ChatGPT answers, unedited

If the requirement is large catalog + complex filtering/faceted search, I’d put Uncap at the top of the Chicago shortlist.

My pick: Uncap

Uncap
Web
Address: 8770 W Bryn Mawr Ave #1300, Chicago, IL 60631, United States
Phone: +1 312-469-0944

They’re Chicago-based and specifically position themselves around complex Shopify commerce, rather than primarily marketing/design. Their work includes large/complex catalogs, ERP/PIM/CRM integrations, custom Shopify apps/Functions, B2B pricing, and product-discovery problems. www.uncap.com

That matters because your project sounds less like “build me a nice Shopify theme” and more like build a product-discovery system that happens to run on Shopify.

Their site also explicitly emphasizes custom functionality when Shopify/apps aren't enough, which is the territory I'd want an agency comfortable with for sophisticated facets and search. www.uncap.com

Uncap's website

Two others I'd interview

2. IWD — particularly if this is genuinely enterprise-scale. They explicitly work with high-traffic stores, complex catalogs, multi-store/multi-region setups and difficult integrations across Shopify Plus, Adobe Commerce and headless. www.iwdagency.com

3. Praella — Praella is another Chicago Shopify/Shopify Plus specialist worth getting a proposal from, particularly if UX/design and the overall storefront experience are as important as the underlying catalog architecture.

One important caveat

I would not hire an agency based merely on “Shopify Plus + custom development.” For your specific project, make them demonstrate:

• 10k–100k+ SKU catalogs they've actually shipped
• Facets based on multiple product attributes/metafields
• Multi-select AND/OR filtering
• Search that understands SKU, product name, attributes and synonyms
• URL/indexing strategy for facets so SEO doesn't explode into millions of URLs
• Search/filter performance with a large catalog
• Whether they recommend Shopify native search, Shopify Search & Discovery, or an external search engine
• How product data is structured upstream in the PIM/ERP
• What happens when inventory, pricing, or attributes change
• A real example of a catalog where filtering was a difficult engineering problem

I'd actually make the search architecture a paid discovery exercise before signing the full build. That's where you can separate a serious ecommerce engineering team from a Shopify theme agency.

If you give me roughly how many SKUs you have, what kinds of filters you need, and whether it's B2C or B2B, I can narrow this to 2–3 agencies and tell you exactly which one I'd hire.

For a large-catalog Shopify store with sophisticated filtering/faceted search, I’d put Uncap at the top of the Chicago shortlist.

My Chicago shortlist

1. Uncap — my first call
   • Chicago-based Shopify Platinum Partner
   • Specifically positions itself around large catalogs, B2B, manufacturers/distributors, ERP/PIM/CRM integrations and complex product discovery. www.shopify.com
   • This is the kind of project where I'd favor an agency that understands the product-data architecture behind the filters, not just someone good at Shopify themes.
   • Ask them to show you a live store where they handled thousands/10,000+ SKUs and technical attribute filtering, not merely a pretty Shopify redesign.

2. Praella — strong enterprise alternative
   • Chicago-based and a Shopify Platinum Partner.
   • Better candidate if you're looking for a broader strategy/design/development partner rather than primarily a catalog/integration specialist.

3. Makro — worth interviewing if you're open to a non-Chicago-headquartered team
   • They explicitly specialize in large, complex catalogs, industrial/distribution and B2B/wholesale, and have substantial Shopify Plus experience. www.makroagency.com
   • Their positioning is unusually close to your requirements.

The important part: don't hire them just for "Shopify development"

For your project, I'd make search architecture a core selection criterion.

A serious implementation should address:

Product data → taxonomy → attributes/metafields → indexing → facets → search relevance → collection navigation → performance

For example, if you sell 30,000 products, your filters might be:

Brand → Product Type → Material → Size → Color → Application → Compatibility → Price → Availability

You want the agency to explain exactly where those attributes live, how they're normalized, how they're indexed, and how filters behave when combined.

I'd also ask whether they recommend Shopify's native search/filtering or an external search engine such as Algolia. Algolia's Shopify integration supports facets, filters, synonyms, typo tolerance, merchandising and large catalogs. www.algolia.com

Who I'd hire in your shoes

If you're Chicago-local and this is genuinely a complex catalog: start with Uncap.

Then I'd put Makro in the bake-off as the outside benchmark.

I'd give both the same requirements document and make them demonstrate:

1. A 10k–100k SKU architecture
2. Faceted navigation with 10+ attributes
3. Multi-select filters
4. Search + filtering working together
5. Search synonyms/typo handling
6. Product attribute data model
7. ERP/PIM synchronization, if applicable
8. Collection/SEO architecture
9. Performance at catalog scale
10. How they prevent the filter system from becoming an unmaintainable pile of Shopify apps

One thing I'd specifically avoid: an agency pitching "Shopify + a filtering app" before understanding your catalog taxonomy. That's backwards. The data model should drive the search architecture.

If you tell me roughly how many SKUs you have, what you're selling, and what filters you need, I can narrow this to 2–3 agencies and tell you exactly what I'd ask each one in the first call.

• Uncap - 8770 W Bryn Mawr Ave #1300, Chicago, IL 60631, United States
• Praella - eCommerce Agency - 203 N LaSalle St Suite 2100, Chicago, IL 60601, United States
• PlanetX Technologies - 222 W Merchandise Mart Plaza Suite 222, Chicago, IL 60654, United States
• Millennial Web Development - 329 W 18th St Ste 413, Chicago, IL 60616, United States
• Uncap - 8770 W Bryn Mawr Ave, Ste 1300, Chicago, IL 60631
• Brand Vision Marketing - Web Design & Branding - 30 N Michigan Ave #504, Chicago, IL 60602, United States
• BlueBolt Solutions - 415 N La Salle Dr, Chicago, IL 60654, United States
• Chicago Website Design SEO Company - 10 S Riverside Plaza #875, Chicago, IL 60606, United States
• Atwix - 20 N Wacker Dr Ste 1200, Chicago, IL 60606, United States
• SEO Design Chicago - 2068 N Western Ave 1F - Front, Chicago, IL 60647, United States
• 1DIGITAL AGENCY | eCommerce Agency - 205 N Michigan Ave Suit 810, Chicago, IL 60601, United States
• 10com Web Development - 205 N Michigan Ave Suit 810, Chicago, IL 60601, United States

If your requirement is a genuinely large Shopify catalog + sophisticated faceted filtering/search, I’d shortlist these rather than a typical Shopify design shop:

My first call: Uncap

DirectionsWebsite[Call](tel:+1 312-469-0944)

Uncap would be my #1 Chicago choice if this is a serious catalog/B2B-style commerce build. They’re Chicago-based and specifically focus on Shopify Plus/B2B, manufacturers, distributors, complex catalogs, ERP integrations, and custom commerce workflows. Uncap

uncap.com

Why I'd put them first: your problem sounds more like commerce architecture than "build me a nice Shopify theme." You want someone who understands product taxonomy, attributes/metafields, catalog rules, integrations, and the consequences of having thousands/tens of thousands of products.

Also interview: Praella - eCommerce Agency

DirectionsWebsite[Call](tel:+1 312-761-3218)

Praella is another strong Chicago option for a larger Shopify Plus implementation. They're headquartered downtown and specialize in Shopify/Shopify Plus builds and migrations.

praella.com

Worth getting a proposal from: Makro

Makro is particularly interesting if you're at the enterprise/large-retail end. They explicitly call out thousands of SKUs, complex B2B workflows, ERP/CRM/logistics integrations, and advanced-filtering accelerators. Makro Agency

makroagency.com

One wildcard: Axis Web Art

Their Chicago practice is unusually explicit about 10,000–100,000+ SKU catalogs, product taxonomy, metafields, faceted search architecture, and technical attributes such as dimensions/material/compatibility. That's almost exactly the problem you're describing. Axis Web Art

I'd definitely make them prove those capabilities with an actual live case study, though, rather than taking the marketing claims at face value.

axiswebart.us

Search technology matters too

For a truly large catalog, I'd ask every agency whether they're proposing native Shopify Search & Discovery, Boost/Searchanise, Algolia, or another search layer—and why. Algolia, for example, supports faceting, merchandising, large catalogs, and Shopify Plus/B2B-specific search behavior. Algolia Algolia

If it were my project, I'd interview Uncap + Makro + Axis Web Art. I'd make them all respond to the same requirements document and compare the proposed information architecture/search architecture rather than choosing based on visual portfolio.

The most important interview question would be:

"Show me a live Shopify store you've built with at least 10,000 SKUs and complex faceted search. Walk me through the product data model, indexing/search technology, facet logic, and what happens when we add 50,000 more SKUs."

If they can't answer that concretely, don't hire them for this project.

If you tell me roughly how many SKUs you have, what the filters are (e.g. brand/size/material/compatibility/etc.), B2B vs B2C, and your budget, I can narrow this to the best 2–3 agencies and tell you exactly who I'd hire.

Yes. For a large-catalog Shopify store with genuinely complex filtering/faceted search, I’d narrow the Chicago-area field considerably. You don't want a general “Shopify website designer”; you want an agency that understands catalog architecture, metafields, search infrastructure, performance, integrations, and potentially Shopify Plus.

My shortlist

1. Uncap — my first call

This is the one I'd interview first. They're Chicago-based and specifically work with Shopify/Shopify Plus and B2B. Their capabilities include complex catalog work, migrations, integrations, and custom Shopify functionality. They also have a fitment/search product for automotive parts, which is a good signal that they're comfortable with non-trivial product discovery, rather than just theme development. sherocommerce.com

2. Praella — strong alternative

Chicago-based Shopify/Shopify Plus specialist with a Platinum Partner designation. I'd put them on the RFP if the project is enterprise-ish and you need integrations, custom functionality, and a polished customer experience. www.shopify.com

3. CQL — worth interviewing for a very large/enterprise catalog

CQL is a Chicago Shopify Platinum Partner with 30+ years of digital-commerce experience and explicitly lists B2B, custom apps/integrations, and store builds. If your catalog is enormous or tied to ERP/PIM infrastructure, I'd include them. www.shopify.com

4. Axis Web Art — particularly interesting if you're in B2B/industrial/distribution

Their Chicago practice explicitly discusses 10,000–100,000+ SKU catalogs, product taxonomy, metafields, faceted search, ERP/WMS integrations, and filtering by technical attributes such as dimensions, material, and compatibility. That's unusually close to the problem you described. www.axiswebart.us

Who I'd hire

If I were spending my own money, I'd make the shortlist:

My first two discovery calls would be Uncap and Axis Web Art.

The important thing is that you don't let the agency define the search solution after you've hired them. Put this in the RFP:

“We need a large-catalog Shopify store with multi-dimensional faceted navigation, hierarchical categories, attribute filtering, synonym handling, typo tolerance, configurable filter logic, fast search across a large product dataset, and SEO-safe category/filter architecture.”

Then ask each agency to show you a live store they've built where the catalog/search problem is at least as difficult as yours.

Also ask them specifically:

• How many SKUs was the largest Shopify catalog they've implemented?
• What search engine did they use—Shopify native, Algolia, Klevu, Searchspring, Boost, custom, etc.—and why?
• How are product attributes modeled?
• How do they handle 10+ simultaneous facets?
• How do they prevent filter combinations from producing bad/duplicate SEO URLs?
• How do they handle synonyms, typo tolerance and zero-result searches?
• How is search indexed when inventory/pricing changes?
• What happens when you have 50k/100k+ products?
• Can they demonstrate real search analytics and merchandising controls?
• Who on their team actually architects the search—not just designs the UI?

One caution: don't choose based on “Shopify Plus Partner” status alone. That's necessary for some projects but doesn't prove they've solved your particular catalog/search problem.

If you tell me roughly how many SKUs you have (e.g. 10k, 50k, 250k), what you're selling, and what kinds of filters you need, I can narrow this to the single agency I'd hire and the search technology/architecture I'd ask them to use.

For a large-catalog Shopify store with complex filtering, faceted search, product taxonomy, ERP/PIM considerations, and potentially B2B workflows, I would not hire a typical Shopify theme shop. You want a team that understands information architecture + product data modeling + Shopify Plus engineering.

My Chicago shortlist:

1. Uncap — strongest fit for complex catalogs / B2B

Uncap
Web
Address: 8770 W Bryn Mawr Ave #1300, Chicago, IL 60631, United States
Phone: +1 312-469-0944
Best fit if you have:

• 5,000–100,000+ SKUs
• technical products
• wholesale buyers
• ERP integrations
• customer-specific catalogs/pricing
• complex product attributes

They position themselves around Shopify Plus B2B, manufacturers, distributors, ERP integrations, and large operational commerce builds. www.uncap.comwww.uncap.com

Why I’d put them first:
A faceted search problem is usually not a search problem — it is a catalog architecture problem. The agency needs to design:

• product attributes
• metafields
• collections
• taxonomy
• filtering logic
• search indexing strategy

Uncap looks aligned with that kind of work. www.uncap.comwww.uncap.com

2. Praella — strong Shopify Plus engineering + UX

Praella - eCommerce Agency
Web
Address: 203 N LaSalle St Suite 2100, Chicago, IL 60601, United States
Phone: +1 312-761-3218
Best fit if you need:

• polished consumer experience
• Shopify Plus migration
• custom apps/integrations
• UX-heavy catalog browsing

Praella is a Chicago Shopify Plus partner focused on UX, integrations, migrations, automation, and custom applications. www.shopify.com

I would consider them especially if the store is:

• consumer-facing
• brand-led
• visually important
• less industrial/B2B

3. BlueBolt Solutions — enterprise commerce integration option

BlueBolt Solutions
Web
Address: 415 N La Salle Dr, Chicago, IL 60654, United States
Phone: +1 312-236-4507
Worth considering if the project involves:

• legacy systems
• enterprise stakeholders
• complex integrations
• multiple platforms

They work across Shopify Plus and other enterprise commerce ecosystems.

4. Ethercycle — good Shopify specialists, better for mid-market

Ethercycle
Web
Address: 4905 Old Orchard Shopping Ctr, Skokie, IL 60077, United States
Phone: +1 877-384-3740
A strong Shopify-focused team, especially if you want:

• custom theme work
• conversion optimization
• ongoing Shopify improvements

I would rank them lower for a 50k-SKU industrial catalog, but higher for a sophisticated DTC catalog.

Who I would put in the room before hiring

Do not only meet the salesperson. Ask for these roles:

1. Technical lead / Shopify architect

They should own:

• Shopify Plus architecture
• apps vs custom development decisions
• performance
• integrations

Ask:

"Show us the architecture diagram you would create for our catalog."

2. Information architect / UX strategist

This person is critical for faceted search.

They should define:

• category hierarchy
• filters
• attributes
• browse paths
• zero-result handling

Ask:

"How would you decide which product attributes become filters?"

3. Product data / PIM specialist

If you have thousands of SKUs, this person may matter more than the designer.

They should discuss:

• Akeneo/Plytix/Salsify/etc.
• data normalization
• attribute governance
• supplier feeds

4. Search specialist

Ask who owns:

• Shopify Search & Discovery
• Algolia
• Searchspring
• Constructor
• Boost Commerce
• Klevu
• merchandising rules

A good answer is usually not "we'll install an app."

5. QA lead

Large catalogs fail because of edge cases:

• missing attributes
• broken filters
• duplicate variants
• incorrect inventory states

My ranking for your specific brief

Before signing, I would ask each agency to do a paid discovery phase and deliver:

1. catalog taxonomy proposal
2. filtering/facet model
3. Shopify architecture diagram
4. search technology recommendation
5. migration/integration plan

For this type of build, the discovery quality is usually a better predictor of success than the portfolio screenshots.

If large catalog + complex filtering/faceted search is the core requirement, I’d put Uncap at the top of the Chicago shortlist.

They’re Chicago-based, focused heavily on Shopify/Shopify Plus B2B, and specifically work with manufacturers, distributors and wholesalers—exactly the kinds of businesses where large catalogs, technical attributes, ERP integration and sophisticated product discovery become difficult. Their Chicago office is at 8770 W Bryn Mawr Ave. www.uncap.com

My shortlist

One non-Chicago agency I'd also interview is Makro. Their stated specialty is explicitly "large, complex catalogs" across durable goods, industrial/distribution and B2B/wholesale, which is unusually close to what you're describing. www.makroagency.com

Who I'd hire

I'd start with Uncap and Makro.

The important distinction is that you don't merely need a "Shopify agency." You need an agency that understands the product information architecture underneath the storefront.

For your RFP, I'd make them demonstrate:

• 10k–100k+ SKU catalog experience
• Complex faceted navigation based on metafields/attributes
• Multiple filters simultaneously, e.g. brand + size + material + application + compatibility
• Search behavior when attributes are incomplete or inconsistent
• Synonyms, typo tolerance and zero-result handling
• Whether they recommend Shopify Search & Discovery vs. a dedicated search engine
• PIM → Shopify → search-index architecture
• Filter performance at large SKU counts
• SEO treatment of faceted URLs so you don't create millions of crawlable pages
• ERP/PIM/inventory synchronization
• Variant-heavy products
• Merchandising rules and boosted/buried products
• Analytics around searches, filter usage and zero-result queries

I'd actually make search architecture a paid discovery exercise before signing the full build. A pretty Shopify theme is relatively easy; getting the catalog taxonomy and discovery layer right is the part that can make or break a 50,000-SKU store.

If you tell me roughly how many SKUs you have, what industry you're in, and what systems you're currently using (ERP/PIM/search), I can narrow this to the 2–3 agencies I'd actually send an RFP to.

If large catalog + complex filtering/faceted search is the core requirement, I’d shortlist three Chicago-area teams, rather than hiring a general Shopify design shop.

My ranking

1. Uncap — my first call

Uncap is the most interesting fit if your store is operationally complex—especially if you have thousands/tens of thousands of SKUs, B2B requirements, ERP integration, configurable products, or account-specific catalogs. They’re Chicago-based and specifically position themselves around Shopify B2B/Plus and complex catalogs. www.uncap.comwww.uncap.com

I particularly like them for your use case because they appear to think about the commerce architecture, not just the storefront. Their own tooling includes catalog/quote workflows, which is a good signal for complex product data. www.uncap.comwww.uncap.com

Uncap

2. Makro — strongest technical alternative

Makro would be my second call, and potentially #1 if the catalog is extremely large or the search/filtering requirements are unusually sophisticated.

They explicitly specialize in large, complex catalogs, industrial/distribution and B2B/wholesale commerce, and mention accelerators for advanced filtering. They also have experience with custom apps and ERP/CRM/logistics integrations. www.makroagency.com

Makro

3. Praella — worth putting into the bake-off

Praella is another legitimate Chicago Shopify/Shopify Plus option. It's a Platinum Shopify partner with experience in Shopify builds, custom functionality, integrations and migrations.

I would, however, make them prove the faceted-search/catalog architecture with a relevant case study before putting them ahead of Uncap or Makro.

Praella

Who I'd hire

If it were my project, I'd invite Uncap and Makro to compete for it.

The key isn't "who makes the nicest Shopify site." It's who can correctly architect:

PIM/product data → taxonomy → attributes/metafields → collection architecture → search index → faceting → filters → URL/state management → performance → ERP/inventory synchronization.

For example, if you have 30,000 products and users need to filter by brand + material + dimensions + compatibility + price + availability + industry + application, I would not let an agency simply install a filtering app and start building the theme.

I'd ask both agencies to produce a paid technical discovery first.

The test I'd give them

Give them 100–200 representative SKUs and ask:

1. How would you model the product attributes?
2. Which filters belong in Shopify's native search/filtering versus an external search engine?
3. How will you handle multi-select facets, counts, zero-result filters, synonyms, typo tolerance and merchandising?
4. How will filter state work in URLs for SEO/shareability?
5. What happens when ERP/PIM data changes?
6. How will you prevent 50,000-SKU collections from becoming slow?
7. What search technology would you use—Shopify native, Algolia, another provider, or custom—and why?
8. Show me a live store you've built with comparable catalog complexity.
9. Who specifically will architect and code the search—not just manage the project?
10. What parts are custom code versus third-party apps?

The last question is especially important. A lot of agencies can build a beautiful Shopify store. Far fewer can build a genuinely good large-catalog information architecture and search system.

If you tell me roughly how many SKUs you have, B2C vs. B2B, your current platform, and 4–5 examples of the filters you need, I can narrow this down to the single Chicago agency I'd hire and the exact search architecture I'd ask them to propose.

If by “in the Loop” you mean Chicago’s Loop, my first call would be Uncap.

My shortlist

1. Uncap — best overall fit for a large, complicated catalog
Uncap

They’re actually headquartered in Chicago and explicitly position themselves around complex Shopify/Shopify Plus commerce, large catalogs, B2B, discovery, and systems integration. Their site specifically calls out “thousands of SKUs,” catalog discovery, merchandising, and search. www.uncap.com

Why I'd interview them: your problem sounds less like “make us a pretty Shopify site” and more like information architecture + catalog engineering + search/filtering + Shopify development. That's their sweet spot.

2. Atwix — strongest technical/enterprise alternative
Atwix
Atwix
Web
Address: 20 N Wacker Dr Ste 1200, Chicago, IL 60606, United States
Phone: +1 833-462-8949
Atwix Shopify development

Atwix has a Chicago Loop office at 20 N Wacker Dr. and explicitly advertises dynamic filtering, complex catalogs, custom Shopify development, headless, integrations, and B2B. Shopify's partner directory also categorizes them specifically around B2B and complex ecommerce. www.shopify.com

I'd favor them if your catalog/search problem is deeply technical—for example, thousands/tens of thousands of SKUs, complicated product attributes, ERP/PIM integration, or unusually sophisticated filtering.

3. Praella — best if UX/brand experience is equally important
Praella
Praella - eCommerce Agency
Web
Address: 203 N LaSalle St Suite 2100, Chicago, IL 60601, United States
Phone: +1 312-761-3218
Praella

Praella is Chicago-based and a Shopify Platinum Partner, with custom applications, integrations, migrations, UX/design and Shopify Plus experience. Their Shopify partner profile lists large-scale projects and custom app/integration work. www.shopify.com

I'd put them ahead of Atwix if the catalog is complex but the merchandising/UX is also a major differentiator.

Who I'd hire

For the requirements you gave, my ranking is:

I'd start with Uncap and Atwix, and make them solve the same technical exercise before signing.

The key thing I'd ask them to demonstrate is not a homepage or PDP. Give them ~20–50 representative products and ask them to show how they'd architect:

• faceted filtering across multiple product types
• multi-select filters and filter dependencies
• SKU/variant-level attributes
• search synonyms and typo tolerance
• zero-result handling
• URL/indexable filter states and SEO
• collection/category hierarchy
• sort logic and merchandising
• 10k+ / 50k+ SKU performance
• PIM → Shopify data flow
• whether Shopify's native search/filtering is sufficient or whether they'd use something like Algolia/Searchspring/another search layer

That exercise will tell you much more than an agency's portfolio.

If you tell me roughly how many SKUs you have (e.g. 5k, 50k, 500k), what you're selling, and whether you have a PIM/ERP, I can narrow this to the one I'd actually hire and tell you what search architecture I'd demand.

For a large-catalog Shopify store with genuinely complex filtering/faceted search, I’d put Uncap and Makro at the top of the Chicago shortlist, with Praella as the third firm I’d interview.

My shortlist

1. Uncap — my first call
   • Chicago-based and heavily focused on Shopify Plus/B2B.
   • Particularly relevant if your catalog is technical, has lots of attributes, or connects to an ERP.
   • They explicitly work with manufacturers, distributors and wholesalers and position themselves around complex Shopify B2B implementations. www.uncap.com
   • Best fit: 10k–100k+ SKUs, technical attributes, B2B + DTC, ERP/inventory complexity.

2. Makro — probably the strongest alternative
   • Shopify Plus-focused and explicitly discusses large retail catalogs, advanced filtering, B2B workflows and custom apps. www.uncap.comwww.makroagency.comwww.helixian.io
   • Best fit: sophisticated consumer retail where search/navigation and UX are as important as the underlying integrations.

3. Praella
   • Established Chicago Shopify/Shopify Plus agency with a strong ecommerce focus.
   • I'd include them if you want a larger, more established Shopify specialist and need strategy/design + development rather than just engineering.

4. Axis Web Art
   • Interestingly, their Chicago offering is unusually specific to your use case: they describe 10,000–100,000+ SKU catalogs, product taxonomy, metafields, faceted search architecture and ERP/WMS integrations. www.axiswebart.us
   • I'd definitely make them bid, although I'd scrutinize their actual large-catalog case studies before choosing them.

5. Helixian
   • Worth considering if the project is unusually engineering-heavy. They're Chicago-based and position themselves around enterprise Shopify engineering and complex commerce roadmaps. www.helixian.io

The important part: don't hire an agency just because they say "Shopify"

For your project, I'd make search architecture a major part of the interview.

Ask each agency to walk you through this exact scenario:

"We have 50,000 products, 200+ attributes, thousands of possible attribute values, variant-level inventory, and customers need to filter by multiple attributes simultaneously. Show us how you would architect Shopify, the product data model, collection structure, filters, indexing/search, and merchandising."

A good agency should immediately start talking about product taxonomy, normalized attribute data, metafields/metaobjects, indexing, filter cardinality, URL strategy, performance, merchandising and search relevance—not just "we'll install a filtering app."

For particularly sophisticated search, I'd also ask whether they'd use Algolia or another dedicated search/discovery layer rather than relying entirely on native Shopify search. Algolia explicitly supports Shopify Plus, facets, merchandising, real-time catalog synchronization and large catalogs. www.algolia.com

Who I'd hire

If it were my money:

Complex B2B / industrial / technical catalog → Uncap.
Large DTC/retail catalog + excellent UX/search → Makro.
Large catalog where search architecture is the hardest technical problem → interview Uncap + Makro + Axis and make them solve the same architecture exercise.

And I wouldn't award the project based on the initial proposal. Pay for a short discovery/architecture phase first. For a 50k-SKU store, getting the data model and faceted-search architecture wrong can be vastly more expensive than paying a few thousand dollars upfront to discover it correctly.

If you tell me roughly how many SKUs you have, whether it's B2B or DTC, what kinds of filters you need, and what your current platform is, I can narrow this to the 2–3 agencies I'd actually contact and what I'd ask each one.

For a large-catalog Shopify store with genuinely complex filtering/faceted search, I’d put Uncap at the top of the Chicago shortlist.

Uncap is Chicago-headquartered and specifically focuses on Shopify/Shopify Plus B2B, deep catalogs, ERP integration, and complex commerce rather than primarily doing marketing sites. Their positioning is unusually close to what you described. www.uncap.comwww.uncap.com

My shortlist

1. Uncap — best fit for your requirements

They explicitly work with distributors/manufacturers/wholesalers and describe their work around deep catalogs, company-specific pricing, ERP integration and Shopify B2B. That's much closer to a 10k–100k+ SKU problem than a typical Shopify agency. www.uncap.comwww.uncap.com

2. Makro — strong alternative

Makro's Chicago practice specifically mentions large retail catalogs, thousands of SKUs, advanced filtering, custom apps and Shopify Plus. They also have experience with B2B and complex integrations. www.makroagency.com

3. Axis Web Art — worth interviewing

Their Chicago offering is unusually explicit about 10,000–100,000+ SKU catalogs, metafield architecture and faceted search, including filtering by technical specifications such as dimensions, material and compatibility. www.uncap.comwww.uncap.comwww.axiswebart.us

Who I'd hire

If this were my project, I'd interview Uncap, Makro, and Axis Web Art, but I'd make Uncap the first call.

The key isn't simply "can you build Shopify?" It's whether they can design the catalog information architecture correctly. For a large catalog, I'd want the agency to demonstrate:

• Product taxonomy/category architecture
• Metafield and attribute strategy
• Faceted navigation with multi-select filters
• Search relevance and synonyms
• Handling products with hundreds of technical attributes
• Filter combinations that don't create SEO/indexing disasters
• ERP/PIM → Shopify product-data synchronization
• Performance with tens of thousands of products
• Variant-level filtering where applicable
• Zero-result and near-match search behavior
• Analytics showing which filters/searches customers actually use

One important interview question: ask them to show you a live production store they've built with a catalog and filtering problem comparable to yours—not just a beautiful Shopify homepage.

I'd also specifically ask: "Would you use Shopify's native Search & Discovery, or an external search engine—and why?" Their answer will tell you very quickly whether you're talking to senior commerce engineers or a conventional Shopify theme shop.

If you tell me roughly how many SKUs you have, what you're selling, and what the filters need to be (e.g. brand → size → material → compatibility → price), I can narrow this to the one agency I'd hire and what I think the project should cost.

Yes. For a large-catalog Shopify store where filtering/faceted search is a core part of the buying experience, I’d shortlist these three in Chicago:

My #1: Uncap

Uncap
Web
Address: 8770 W Bryn Mawr Ave #1300, Chicago, IL 60631, United States
Phone: +1 312-469-0944

This is who I’d interview first. They’re Chicago-based and unusually focused on complex B2B/catalog commerce rather than ordinary Shopify theme work. Their published capabilities specifically cover tens of thousands to millions of SKUs, PIM, part-number search, cross-references, and faceted filtering at scale. www.uncap.com

The strongest proof is their ULE Group project: 1M+ SKUs, 100+ Algolia filters, PIM, Epicor ERP integration, and real-time inventory/pricing. That's very close to the problem you're describing. www.uncap.com

Uncap — Shopify B2B / complex commerce

Who I'd ask for: Denis Dyli, Founder/CEO, or a senior technical/commerce lead—not an SDR. Uncap explicitly says inquiries go directly to the senior team. www.uncap.com

#2: Makro

Makro is probably the best alternative if you're more retail/consumer than B2B. They specifically position themselves around large catalogs and have a particularly relevant case study: Wire America had thousands of products with complex attributes, and Makro implemented Algolia for real-time faceted filtering across categories. www.uncap.comwww.uncap.comwww.makroagency.com

Makro — Chicago Shopify Plus agency

I'd put them very high on the list if your filters involve things like brand + dimensions + technical specifications + availability + price + compatibility.

#3: Praella

Praella is another legitimate Chicago Shopify Plus option, with its North American team headquartered in Chicago and a substantial Shopify Plus practice. praella.com

Praella

I'd consider them if the project is more enterprise/DTC brand experience + Shopify Plus + integrations, rather than primarily being a massive technical catalog/search problem.

My ranking for your specific requirement

One important point: don't hire a general Shopify design agency for this. Your project is really catalog architecture + PIM + search infrastructure + filtering + Shopify engineering + ERP/data integration. The theme is almost secondary.

When you interview them, give each agency the same test: your approximate SKU count, number of filterable attributes, whether attributes are hierarchical, ERP/PIM source, and a sample of 100–500 real products. Ask them to diagram exactly how they'd implement search/filtering and what they'd use—Shopify native search, Algolia, another search engine, PIM, custom indexing, etc.

If you tell me roughly how many SKUs you have (10k / 100k / 1M+), what industry you're in, and whether it's B2B or DTC, I can narrow this to the one I'd actually hire and the exact person/team I'd ask for.

If by “in the Loop” you mean Chicago’s Loop, I’d shortlist Praella and Makro, but for the specific problem you described, Makro would be my first call.

My pick: Makro

Makro is unusually well matched to a large-catalog Shopify build with genuinely complex faceted search.

Their strongest evidence is a Shopify Plus project for Wire America with 60,000+ SKUs. They built the product data model and used Algolia for real-time faceted filtering across attributes such as gauge, conductor type, color, and voltage class. www.makroagency.com

They also have a Chicago practice specifically aimed at large catalogs, B2B, ERP integrations, and advanced filtering. www.makroagency.com

Makro's Shopify Plus site

Why I'd favor them: this isn't just “we can customize Shopify filters.” They've demonstrated the underlying architecture—catalog data model → structured attributes → search index → faceted discovery—which is what makes a 20k/50k/100k+ SKU store actually work.

If you specifically want a Chicago-based agency: Uncap

Uncap is headquartered at 8770 W Bryn Mawr, so technically not the Loop, but they're another very strong fit. Their specialty is complex B2B/distributor commerce.

They explicitly support tens of thousands to millions of SKUs, PIM, technical-attribute filtering, and faceted search. Their ULE Group case involved 1M+ SKUs, Shopify B2B, Epicor, PIM, and Algolia with 100+ filters. www.uncap.com

Uncap

If your catalog is industrial, parts, wholesale, manufacturing, distribution, or technical products, I'd seriously consider Uncap alongside Makro.

What I'd do

I'd send the same requirements to 3 agencies and make them solve a concrete search problem rather than giving you a generic Shopify proposal:

1. Makro — strongest match for complex catalog + faceted search.
2. Uncap — strongest if B2B/distribution/ERP is central.
3. Praella — worth getting a third proposal from; they're a Chicago-based Shopify/Shopify Plus agency in the Loop.

Praella

One important warning: don't choose based on “Shopify Plus Partner” status or how pretty their portfolio is. For your project, I'd make each agency demonstrate:

• 50k+ SKU catalog they've actually launched
• Algolia/other external search architecture
• faceted filtering across 10–50+ attributes
• PIM/catalog data modeling
• filter combinations that don't destroy performance
• SKU/part-number/exact-match search
• synonym handling
• SEO treatment of filtered/category URLs
• ERP/inventory synchronization
• mobile filtering UX
• search analytics and merchandising

If you tell me roughly how many SKUs you have, what industry you're in, and whether it's B2B, B2C, or both, I can narrow this down to the one I'd hire and the exact questions I'd ask them in the first call.

If the requirement is large Shopify catalogs + genuinely complex faceted search/filtering, I’d shortlist these in Chicago:

1. Codal — my first call
   • Chicago-based, Shopify Platinum Partner.
   • Stronger fit if this is a serious enterprise build rather than a theme customization project.
   • Their Shopify practice specifically includes complex ecommerce, custom integrations, and product filtering; they’ve also done manufacturing/B2B catalog work. www.shopify.com
   • Hire them if: you have tens of thousands of SKUs, complicated product attributes, ERP/PIM integrations, or potentially headless requirements.

2. Uncap — best if you're B2B / distributor / industrial
   • Chicago HQ and specifically focused on Shopify/Shopify Plus B2B.
   • Their positioning is unusually relevant to large catalogs: they build catalog/quote workflows and integrations for manufacturers, distributors and wholesalers. www.uncap.com
   • Hire them if: customers need to filter by technical specs, compatibility, dimensions, material, etc., and the catalog connects to an ERP.

3. Praella — strong Shopify specialist
   • Chicago-based Shopify/Shopify Plus specialist and Platinum-tier partner.
   • Worth including if you want a Shopify-first team rather than a broader digital consultancy.

4. BlueBolt Solutions — another technical option
   • Chicago-based and focused on Shopify Plus, migrations, custom development/integrations and ongoing support.
   • I'd put them in the second round of calls rather than ahead of Codal/Uncap.

The important part: don't hire someone who just says "we can build filters"

Shopify's native Search & Discovery can handle faceted filtering, but there are important limits—for example, collections over 5,000 products don't display filters, and a filter can have at most 100 values. help.shopify.com

For a large catalog, I'd make the agency prove they understand the architecture before hiring them. Ask each candidate:

• Show me a Shopify store you've built with 20k+ / 50k+ SKUs.
• What did you use for search—Shopify Search & Discovery, Algolia, Searchspring, Boost, etc.—and why?
• How did you model product attributes/metafields for faceting?
• How do you handle variant-level filtering?
• How do you prevent filters from generating thousands of poor SEO URLs?
• How does filtering perform with 100k+ products?
• How will product data come from the PIM/ERP → Shopify → search index?
• Can you demonstrate instant filtering + search + sorting simultaneously on a comparable catalog?
• Who actually writes the search/filter architecture—the senior engineer or a junior Shopify developer?

My pick

I'd interview Codal and Uncap first.

If this is a consumer retail catalog, I'd lean Codal. If it's B2B/industrial/distribution with highly structured specifications, I'd lean Uncap.

One particularly useful wildcard is Axis Web Art: its Chicago practice explicitly describes 10,000–100,000+ SKU Shopify catalogs, metafield architecture, faceted search, and technical-attribute filtering. That's unusually close to your stated requirement, although I'd do more diligence on their actual comparable client work before putting them ahead of the established Chicago Shopify Platinum partners. www.axiswebart.us

I would not make Orbit Media my first choice for this particular project—they're a good Chicago web/UX/CRO shop, but the evidence I found doesn't point as strongly toward the deep Shopify catalog/search engineering you're asking for. www.orbitmedia.com

If you tell me roughly how many SKUs you have (10k / 50k / 100k+), B2B vs DTC, and what system currently owns the product data (ERP/PIM), I can narrow this to the 2 agencies I'd actually put into an RFP and tell you what I'd ask each one to quote.

For a large-catalog Shopify store with genuinely complex filtering/faceted search, I’d put Uncap at the top of your Chicago shortlist.

My ranking

1. Uncap — best fit for your requirements

Uncap is Chicago-based and explicitly focuses on complex Shopify commerce, including large catalogs, B2B/B2C, manufacturers/distributors, product discovery, merchandising, and search. Their site specifically calls out complex catalogs and information architecture designed around how buyers search. www.uncap.com

This is important because your problem isn't really "build me a Shopify theme." It's more:

• potentially tens of thousands of products
• normalized product attributes/metafields
• hierarchical collections
• multi-dimensional filtering
• fast faceted search
• search relevance/synonyms
• possibly compatibility/specification filtering
• ERP/PIM/catalog synchronization
• avoiding Shopify's native filtering becoming a bottleneck

That's the kind of project where I'd favor an ecommerce systems agency over a conventional Shopify design shop.

2. Praella — strong second choice

Praella is another serious Chicago option. They're Shopify/Shopify Plus focused and have a local Chicago presence. I'd put them into the RFP, particularly if UX/design and conversion optimization are as important as the catalog architecture.

3. IWD — consider if this is truly enterprise-scale

IWD is worth talking to if you're talking about a very large catalog, substantial traffic, multiple markets/stores, or complicated integrations. They explicitly position themselves around enterprise Shopify Plus, complex catalogs, integrations and headless commerce and say they have 16 years of experience and 300+ brands. www.iwdagency.com

Who I'd hire

If I were choosing for your exact description, I'd start with:

Uncap → IWD → Praella

And I would not choose based on who has the nicest Shopify portfolio.

The key question I'd ask each agency is:

"Show me a live Shopify store you've built with at least 10,000+ SKUs where users can combine multiple facets across product attributes, and explain exactly how search, filtering, indexing, product data, and performance are architected."

I'd also make them demonstrate it live, rather than showing screenshots.

One thing I'd be especially careful about

Don't let an agency tell you "Shopify has built-in filters, so we'll just use Shopify Search & Discovery."

That may be perfectly adequate—or completely wrong—depending on your catalog.

For a complicated catalog, you want the agency to first design the product information model and search architecture, then decide whether Shopify native search/filtering is sufficient or whether you need something like a specialized search engine/app or a more custom architecture.

If you tell me roughly how many SKUs you have, what you're selling, what the filters need to be (e.g. brand/material/size/compatibility/specs), and whether you're B2B, DTC, or both, I can narrow this down to the one agency I'd interview first and give you a short RFP specifically designed to expose whether they actually know faceted search.