Your brand is scaling, traffic is growing, and the ecommerce stack is getting harder to manage by the week. At that point, a Shopify Plus agency stops being a vendor search and becomes a strategy decision, because the wrong partner can add app sprawl, slow launches, and costly rework. The right one can keep your storefront fast, stable, and ready for the next growth stage. If you're also trying to improve visibility and sales, this guide to growing sales on Shopify is a useful companion.

Table of Contents

• 1. Presidio

• 2. Domaine (Formerly Half Helix + Tomorrow)

• 3. Diff Agency

• 4. Fuel Made

• 5. Trellis

• 6. Avex

• 7. Praella

• Top 7 Shopify Plus Agencies Comparison

• Beyond the Build Selecting a Partner for Long-Term Growth

1. Presidio

Presidio fits brands that want a hybrid Shopify agency plus product studio, not just a build shop. That matters on Plus, where the challenge is rarely “can you launch a store,” but “can you launch a store that stays maintainable when teams add markets, apps, campaigns, and new features.”

The strongest signal is its focus on a lean, modular foundation. That approach reduces reliance on extra apps, which usually means less technical debt, fewer fragile dependencies, and a cleaner path for future iteration. Presidio also brings an unusually broad toolkit for a single partner, including premium themes like Broadcast, Palo Alto, and Modular, plus apps such as Quiz Kit, Duplify, and Function Junction.

Practical rule: if your team already feels boxed in by app overload, choose the agency that simplifies the stack before it promises more features.

Presidio's service mix is broad enough to cover the full Plus lifecycle. It handles custom themes, custom apps, headless and composable storefronts, migrations, ERP integrations, UX and CRO audits, and ongoing growth programs. That breadth is useful for enterprise DTC teams that need one partner for architecture, conversion, and post-launch support, not three separate vendors passing tickets around.

The social proof is real too. Presidio says its themes and apps are adopted by 100,000+ merchants, and its client roster includes OUAI, Bobbie, OLIPOP, Momofuku, NOBULL, and Vintner's Daughter. That combination of productized tooling and agency delivery makes it a strong fit for brands that want speed without sacrificing long-term maintainability.

Pros

• Hybrid model: combines agency delivery with in-house products, which can simplify execution and vendor management.

• Maintainability first: the lean build philosophy is well suited to brands trying to reduce app sprawl.

• Full-stack capability: supports themes, apps, migrations, integrations, headless builds, and CRO work.

• Strong proof points: broad adoption, award-winning work, and a client list that signals enterprise familiarity.

• Growth orientation: ongoing optimization, experimentation, and personalization are part of the value, not an afterthought.

Cons

• Custom-scoped work: no public pricing means serious projects require discovery and budget alignment.

• Not a starter-shop option: very small merchants may not need this level of scope or investment.

Presidio is the clearest fit for brands that want a shopify plus agency partner with product depth, not just design output.

2. Domaine (Formerly Half Helix + Tomorrow)

Domaine makes sense when the problem is not a storefront refresh, but a large-scale commerce transformation. The merged Half Helix plus Tomorrow organization is built for brands that need migration depth, unified commerce thinking, and enough delivery capacity to handle complicated stakeholder environments.

Its edge is enterprise complexity. Domaine works across strategy, creative, UX, theme and headless engineering, integrations, POS, B2B, and international setups, which is exactly what you need when the site is only one part of a larger commerce system. For brands moving off legacy platforms, that breadth matters more than polished visuals alone.

The migration story is the differentiator. Domaine's public positioning around 150+ migrations and its focus on SFCC and Adobe to Shopify style transitions point to an agency that understands data mapping, operational dependencies, and the political realities of enterprise replatforms. That is not the same skill set as building a beautiful theme from scratch.

Good enterprise agencies reduce risk before they chase novelty.

That said, this level of capability comes with trade-offs. Enterprise programs usually mean heavier process, longer timelines, and more formal coordination. If your team wants a fast, highly iterative build, the structure can feel slow. If your brand needs multi-region governance, B2B workflows, or POS alignment, the structure is often the point.

Domaine is best for mid-market and enterprise brands that are already thinking beyond launch day. It's the kind of agency you hire when the roadmap includes platform migration, international rollout, and ongoing lifecycle growth, not just a website redesign.

3. Diff Agency

Diff Agency is the right conversation when your business wants conversion discipline backed by larger-scale resources. As a WPP company, it sits in a different lane from boutique Shopify teams. That can be a real advantage if your internal process requires more formal governance, more analytics, and more hands around the table.

Its core strength is the combination of strategy, UX, engineering, and A/B testing under one roof. For a Shopify Plus brand, that matters because the biggest gains often come from disciplined experimentation, not a pile of new features. Diff's platform experience also makes it a fit for merchants that need global rollout support or more complex merchandising work.

The main thing to watch is procurement friction. WPP ownership can be useful when you need scale, but it can also slow down smaller teams that want direct access and quick decisions. If your organization moves fast and hates process overhead, that matters.

For teams evaluating post-launch optimization, Diff is a sensible benchmark against CRO-first thinking. Presidio's own conversion rate optimization perspective is a good reference point here, because the best agencies treat CRO as an operating system, not a one-off test plan.

Where Diff tends to work well

• Large brands with formal stakeholders: useful when approvals, reporting, and governance matter.

• Programs needing experimentation: strong if A/B testing and performance analysis are central to the roadmap.

• Teams needing enterprise support: better suited to merchants who value large-firm resources over boutique agility.

Where it can be a mismatch

• Fast-moving founders: the process can feel heavier than necessary.

• Smaller growth teams: the enterprise structure may exceed what they need.

Diff Agency is a strong shopify plus agency option when you want structured experimentation and are comfortable with the operating style that comes with a major holding-company environment.

4. Fuel Made

Fuel Made is a good fit for brands that want iterative growth support instead of a one-and-done build. Its reputation sits in the overlap between Shopify Plus implementation and Klaviyo Elite lifecycle work, which makes sense for merchants who see revenue as a storefront-plus-retention problem.

The practical advantage is continuity. Fuel Made offers an On Tap support model, which signals a retainer-friendly approach for teams that need ongoing updates, tests, and refinements after launch. That's often more realistic than handing the site over and hoping the internal team can carry the optimization load alone.

Fuel Made is especially appealing if conversion, AOV, and email or SMS coordination matter as much as the front end. The agency's value is less about a giant systems architecture and more about making a store perform better through disciplined design and retention work. That's a smart fit for brands that don't need a heavyweight integrator.

Best retained partners don't disappear after launch, they keep tightening the revenue loop.

The limitation is bandwidth. A boutique team can be sharp, but it won't always feel like the right choice for heavy ERP, OMS, or multi-layer enterprise programs. If your operations stack is already complex, you may need a broader systems partner.

Fuel Made works best for brands that want a stable, measurable retainer relationship. If your internal team already owns product and operations but wants external help to keep the site and lifecycle engine improving, this is a strong lane.

5. Trellis

Trellis is a practical choice for brands that want structure, predictability, and full-service support. The agency's Shopify Plus practice is attractive because it packages delivery in a way that helps control both budget and timeline, which is not always common in complex ecommerce work.

That packaging can be a real benefit for mid-market teams. If your business needs a clear path for migrations, design, development, and performance marketing, a more structured engagement model reduces ambiguity. Trellis also brings B2B and omnichannel experience, which matters for brands juggling multiple sales motions.

The migration angle is important here. Trellis is a sensible option for teams moving from Magento, BigCommerce, or similar systems, especially if they want one partner thinking about strategy, creative, tech, and performance marketing together. That integrated approach can shorten the distance between launch and post-launch improvement.

There is a trade-off, though. Package-based delivery can feel restrictive if your build is unusually custom or your roadmap changes often. Some merchants want more flexibility than a defined scope allows. Others prefer that the agency put guardrails around the project so it ships.

For teams worried about the messiness of replatforming, Presidio's ecommerce migration services perspective is a useful parallel. The broader lesson is simple, the best migration partner is the one that protects continuity while letting the new platform do its job.

Trellis is a solid shopify plus agency pick when your priorities are migration control, B2B support, and a delivery structure your internal team can plan around.

6. Avex

Avex is the kind of partner brands choose when they want creative polish without giving up performance thinking. Its New York base and brand-forward style make it especially relevant for fashion, CPG, and DTC companies that care a lot about how the storefront feels as much as how it converts.

The strongest reason to consider Avex is its balance of internationalization, replatforming, UX, and CRO. That matters on Shopify Plus, where multi-region commerce and post-launch iteration often define success more than the launch itself. A visually strong build that can't support regional complexity is only half a solution.

Avex also fits brands that need a partner comfortable with public-facing brand work and measurable outcomes. That blend is valuable when marketing, design, and ecommerce leaders all need to be satisfied by the same build. In practice, that usually means cleaner creative direction and less tension between brand and performance teams.

The downside is straightforward. Boutique and mid-size agencies often have longer lead times, and premium New York pricing is rarely the cheap route. If your team needs a quick start or a cost-contained engagement, you may feel the friction.

Still, Avex is a strong candidate when the storefront has to look as good as it performs. For many premium DTC brands, that's not optional. It's part of the buying experience.

7. Praella

Praella is a strong option for brands that want modern Shopify implementation plus ongoing support. It's comfortable working across design, development, complex integrations, and retainer-style help, which makes it useful for teams that expect the stack to keep evolving after launch.

Its versatility is the main value. Praella can handle Plus builds, replatforms, and integrations around tools like subscriptions, content systems, and retention platforms. That makes it a sensible fit for brands that don't want a rigid, one-size-fits-all approach to their commerce architecture.

Praella is also useful for teams that want a partner able to support iterative changes rather than only a launch event. That matters because many Shopify Plus programs fail not at build time, but after launch, when the merchant needs someone to keep tuning performance, integrations, and merchandising.

The caution is that it does not always present the same depth of enterprise case detail as some of the largest firms. That doesn't mean it can't handle serious work, but buyers with very large systems programs should press for architecture clarity, team depth, and post-launch ownership before signing.

If the agency can't explain how it will stay useful 12 months after launch, keep looking.

Praella is a good shopify plus agency fit for brands that want flexibility, ongoing support, and a modern stack without locking themselves into an overbuilt enterprise program.

Top 7 Shopify Plus Agencies Comparison

Beyond the Build Selecting a Partner for Long-Term Growth

Choosing a Shopify Plus agency is one of the most critical decisions for a growing brand. The best partner isn't just a vendor for a one-time project, they're a strategic asset for your long-term roadmap. That's especially true now that Shopify Plus has scaled from roughly 25,000 merchants in 2022 to more than 47,000 live websites by 2026, with some summaries placing total Plus sites above 60,000 when historical stores are included, according to Charle Agency's Shopify statistics roundup.

The platform's reach at the top end of commerce also explains why agency selection matters so much. One industry source says Shopify Plus powers 9% of the top one million internet sites, even though it represents only 0.22% of all Shopify stores in the same roundup from Charle Agency. That concentration tells you the complexity is real, and the buyers operating at this level need more than generic development help.

The best decision starts with archetype fit. A hybrid product studio like Presidio is strongest when you want maintainable systems, productized tooling, and ongoing optimization in one relationship. An enterprise integrator like Domaine is more appropriate when the challenge is multi-market architecture, B2B, or a legacy replatform. A CRO boutique like Fuel Made makes sense when your store is stable and the next gains will come from iteration, retention, and testing rather than a full systems redesign.

There's also a timing signal worth respecting. A 340,416-store study found Plus adoption rises from 9.1% below 50K monthly visitors to 79.7% at 50K to 200K and 96.4% at 200K to 1M, with 50K monthly visitors identified as the key upgrade threshold, as reported by StoreInspect's upgrade signals analysis. That doesn't mean every brand at that traffic level needs the same agency type, but it does show where complexity often starts to justify enterprise-grade support.

The most reliable buyers ask one question before anything else. Will this agency still make sense once the site is live, the backlog starts growing, and your team needs a partner for the next 18 months, not just the next launch sprint? If the answer is unclear, keep evaluating.

If you want a Shopify Plus agency that blends storefront build quality with product thinking, maintainable architecture, and ongoing optimization, Presidio is built for that brief. Visit Presidio to see how its themes, apps, and custom Shopify Plus services can support your next stage of growth.