The decision to build your store on a headless commerce stack is significant. The decision of which agency to trust with that build is even more so. The wrong choice at this stage sets back timelines, inflates budgets, and leaves teams inheriting code they cannot maintain. The right choice, however, creates a foundation that lets your business grow without being bottlenecked by technology.

This guide is written for CTOs, business founders, and product owners who are evaluating headless commerce agencies, particularly those working with Medusa.js or similar open-source headless platforms. Knowing which questions to ask and what the answers should sound like separates a well-informed buyer from one who gets burned after signing

Why Agency Selection Matters More in Headless Commerce

Traditional ecommerce platforms like Shopify or WooCommerce have well-established agency ecosystems, standardised workflows, and a body of publicly available documentation that makes quality assessment relatively straightforward. Headless commerce is different. The technical complexity is higher, the number of qualified agencies is smaller, and the consequences of a poor technical decision compound over time in ways that are hard to reverse.

When you commission a headless build, you are not just buying a website. You are building infrastructure, data architecture, API contracts, and a frontend delivery layer that your team will interact with for years.

Questions to Ask About Technical Experience

The first category of questions focuses on the agency's actual hands-on experience. Claims about capability are easy to make. The evidence of real delivery is harder to fake.

How many headless commerce projects have you taken to production?

Agencies that have only done proof-of-concept builds or internal demos are fundamentally different from those that have delivered production stores processing real orders. Ask for the number, then ask to speak with a client from one of those projects. A confident agency will facilitate that conversation without hesitation.

Which headless platforms do you work with, and which do you specialise in?

Some agencies present themselves as platform-agnostic, which can mean they are knowledgeable across multiple stacks or that they are mediocre at all of them. If your project involves Medusa.js, ask specifically about the number of Medusa builds they have completed, the versions they have worked with, and the most complex module or workflow they have implemented on the platform. Specificity in the answer is what you are listening for.

Can you show us your storefront architecture for a recent project?

Not the live URL. Ask to walk through the actual architecture. How did they handle server-side rendering? What CDN strategy did they use? How is the checkout flow structured? How are cart states managed across sessions? An agency that can explain these choices clearly and justify them based on the client's actual requirements is one that was building thoughtfully, not just following a template.

Questions to Ask About Project Process

Technical capability without process discipline is one of the most common failure modes in agency relationships. Ask these questions to understand how the agency runs projects, not just whether they can build the thing.

How do you handle scope changes during a project?

Scope changes are inevitable in complex builds. The question is whether the agency has a clear, fair process for handling them. Look for agencies that can describe their change request process, how they document scope, how they estimate change cost, and how they communicate timeline impact. An agency that has no clear answer, or one that says scope changes are always absorbed, is worth questioning further.

What does your QA process look like for a headless storefront?

Headless storefronts have more integration points than monolithic platforms. API calls can fail, checkout flows can break under load, and frontend rendering can produce unexpected behaviour across devices and browsers. A thorough QA process in a headless project includes integration testing, performance testing under realistic traffic conditions, and cross-device verification before launch.

How do you handle knowledge transfer at the end of the project?

This question is one that many businesses fail to ask until they are already in trouble. After the project is delivered, your team or a future agency will need to understand the codebase. Ask what documentation is produced, what handover sessions are included, and whether the team that builds the project will be available for post-launch support or whether the project is handed to a support team unfamiliar with the implementation.

Questions to Ask About Medusa.js Specifically

If your project is being built on Medusa.js, a growing number of agencies will claim experience with the framework. The platform has attracted significant developer interest since version 2.0, but the gap between agencies that have read the documentation and those that have shipped production stores is wide. Firms like Askan Technologies with dedicated Medusa.js practice areas are worth engaging for a detailed technical conversation before shortlisting.

Have you worked with Medusa.js 2.0's module architecture?

The shift from v1 to v2 was substantial. The new module system fundamentally changes how commerce logic is structured and extended. An agency that built on Medusa.js v1 and has not migrated to v2 in a client project may struggle with the new patterns. Ask which version their most recent delivery used and what challenges they encountered during that build.

How do you handle custom Medusa.js workflows?

The workflow engine in Medusa.js 2.0 is one of its most powerful features for complex order logic, subscription scenarios, and multi-step fulfilment processes. Ask the agency to describe a custom workflow they built, what business logic it served, and how they tested it under failure conditions.

What is your frontend stack for Medusa.js projects?

Medusa.js decouples the frontend, which means the agency needs to bring its own frontend strategy. Most production builds use Next.js with the App Router, but the implementation quality varies enormously. Ask about their routing strategy, how they handle SEO for dynamic product pages, and whether they use server components or rely heavily on client-side rendering.

Commercial and Contractual Questions

The technical evaluation is only part of the picture. The commercial relationship needs to be structured clearly to protect both parties and prevent the kinds of disputes that damage long-term partnerships.

What does your pricing model cover, and what is excluded?

Fixed-price contracts provide cost certainty but create incentives for the agency to cut corners on quality when scope is underestimated. Time-and-materials contracts give flexibility but require trust and governance. Many agencies offer a hybrid model. Understand exactly what is included in the quoted price and what triggers additional billing.

Who owns the code after delivery?

For custom headless builds, the intellectual property question matters. You should own the production code delivered for your project. Ask for explicit IP assignment clauses in the contract. This is standard practice and a reputable agency will not resist it. Explore the full scope of ecommerce development services and how they structure IP ownership in their client contracts before you commit.

What does post-launch support include?

The period immediately after a headless store goes live is often the most demanding in terms of support requirements. Bug fixes, performance issues, integration problems, and user experience gaps all surface in the first weeks. Understand exactly what is covered in post-launch support, for how long, and at what cost before you sign.

Evaluating the Agency's Own Technology Thinking

One quality signal that many buyers overlook is the depth of the agency's own thinking about headless commerce as a discipline. Do they publish technical content? Do their engineers contribute to open-source projects or write about what they have learned in production? Agencies that are genuinely invested in the craft tend to share knowledge publicly, which gives you a window into how they think before you ever speak to them. The Askan headless commerce resource is a good example of the kind of thinking a serious headless agency puts into the public domain.

Ask during your evaluation call whether any of the team members you will be working with have contributed to Medusa.js open-source repositories, presented at conferences, or written technical content about headless architecture challenges. This is not a requirement for quality delivery, but it is often a reliable indicator of teams that stay current with the platform's evolution.

The Shortlisting Decision

After you have run your evaluation calls, you will likely have a shortlist of two or three agencies. At this point, move beyond the technical conversation and think about working dynamics. Which team communicated most clearly? Which one pushed back constructively on your assumptions rather than just agreeing with everything? Which one gave you honest answers about what the project would actually take?

The agency that wins the engagement should be the one you would want to call when something goes wrong three months after launch, not just the one that presented the most polished deck. Headless commerce builds are long-term relationships, not single transactions. Choose accordingly.