How to choose an e-commerce agency: 7 questions
If you are planning a large e-commerce build from scratch, look for an agency or software house that has run a store itself, specialises in one stack, quotes the total cost for the first 12 months and puts post-launch support in the contract. Proposals tend to look alike. The differences show about three months after launch, when the agency has moved on to another project and the store is left with technical debt and a roadmap in a spreadsheet. These seven questions help you see them earlier.
Question 1: have you run a store, or only built one?
This question separates suppliers better than any other. Most software houses and agencies build stores from documentation and the client's brief. That is solid work, but it doesn't teach you what happens at 11:55 pm on Black Friday when checkout stops working.
A team that has run a store sets different architectural priorities. Monitoring is in place from day one, a rollback plan is part of the contract, unit costs are visible on a dashboard instead of in a quarterly spreadsheet, and ERP integrations are designed with data reconciliation in mind.
Question 2: how do you calculate cost per order?
A good agency answers this in five minutes. A weaker one spends twenty explaining that it depends and needs a workshop. Cost per order is hosting, licences, platform fees, support time and campaign cost, divided by the number of orders.
This number shows whether the platform investment pays off. If a supplier doesn't think about it at all, they see your store as a project to deliver rather than a business that has to run.
Question 3: what happens after launch?
Most e-commerce projects end in a formal success: launch on time, a signed acceptance report, and the team moves on to the next client. Three months later the store has outdated dependencies, nobody looks after monitoring and nobody is working through the roadmap.
Ask about the specific operating model after launch. Who watches monitoring and alerts? How are incidents handled outside business hours? Does the contract include a fixed number of hours? If the answer is 'we'll quote when needed', assume the planning will fall to you.
Question 4: what do you specialise in?
An agency that claims full coverage of Shopify, Magento, WooCommerce, Medusa.js, Sylius and custom CMSs at the same time is rarely strong in any of them. Ask for documented live projects on a specific platform and for a reference call with a previous client.
For headless commerce, look for teams with hands-on Medusa.js and Next.js experience. The difference shows at the first unusual case: a custom B2B pricing model, an ERP integration with inconsistent data, or a sales peak hitting an API rate limit.
Question 5: what is not included in the quote?
E-commerce quotes often leave out post-launch maintenance and monitoring, ERP and PIM integration, load testing before peak season, migration of historical order data, and fixes in the first month of operation.
Suppliers who price honestly list these items themselves and show how they priced them. Others add them later through contract amendments. Ask for the total cost of the first 12 months, including support.
Question 6: which project did you turn down?
A good agency can name a project it declined and explain why. It shows they take on work they are actually suited to.
In 2025 we turned down three clients at monkydot. In two cases the GMV didn't justify headless, and we told them so. In the third, the scope was outside our expertise and taking it on would have been irresponsible. A company that accepts every project has little reason to get good at any particular kind of work.
Question 7: what would you do differently on your last project?
This question shows whether a company learns from its mistakes. Good teams give concrete answers: a data model error in an ERP integration, an architectural decision they would reverse, or part of the scope they now handle differently.
'We were very happy with the project and wouldn't change anything' should be a warning sign. Every project has something to improve, and a mature company can talk about it openly.
- Running a store and building one are different skills. Ask about both
- Asking about cost per order quickly shows whether a supplier thinks about the running business
- Post-launch support belongs in the contract. If it isn't there, you will have to plan it yourself