Look first at proven experience, not the number of logos on the website. Ask to see two vue or react three case studies that resemble your technology stack, and then find out which engineers actually built it. An honest provider will introduce you to the people who would work on your project. Evasive answers at this stage almost always mean the delivery team is not the team you were shown.

The agreement deserves a slower read than the pitch. A few clauses carry most of the weight: ownership of the code, the NDA, and exit terms and handover. All the work product has to transfer to you as it is paid for, together with source code, designs and infrastructure as code. Watch for any clause that leaves framework code in the vendor's hands, because that is often the dependency that makes switching painful.

Find out how the estimate was built. A credible estimate arrives with a written set of assumptions, a breakdown per feature and a best case and a worst case. A fixed-bid deal works only when the scope is genuinely frozen; in any other case the vendor adds a risk premium and you pay for uncertainty either way. Hourly billing shifts that risk to you, ecommerce web development agency so it needs a cap, regular demos and transparent reporting.

How the work is run beats team size. Establish what happens when the scope changes, who writes the acceptance criteria and how quality assurance works. A well-run team will be able to show you a working build every one or two weeks. Clear, written acceptance criteria are your only real protection against endless rounds of rework.

Before signing, think about the end of the engagement before it becomes urgent. Insist that the source repository sits under your account from the first commit, and that documentation is written as you go rather than left to the end. A partner who is comfortable with this says yes immediately; a long negotiation over it reveals most of what you need to know.