Arden Koenig

Look first at relevant experience, not the number of logos on the website. Request two or three projects that resemble your technology stack, and then ask who actually wrote that code. A solid partner will introduce you to the engineers. Answers that name nobody at this stage generally mean you are talking to a reseller.

The agreement needs more scrutiny than the proposal. Three clauses do most of the work: intellectual property assignment, rest vs graphql comparison non-disclosure, and notice periods and handover. Every artifact should transfer to you as it is paid for, including documentation, pipelines and deployment scripts. Watch for wording that keeps so-called reusable libraries in the vendor's hands, because this is frequently exactly the piece that locks you in.

Ask where their numbers come from. A serious estimate is accompanied by a written set of assumptions, a task-level breakdown and a range rather than a single number. A fixed-bid deal only makes sense when the scope is genuinely frozen; when the scope is still moving the supplier pads the number and you pay for uncertainty either way. Hourly billing puts the risk on your side, so it needs visible weekly reporting and a spending cap.

The delivery process matters as much as team size. Find out what happens when the scope changes, who writes the acceptance criteria and hire backend developers what the QA setup looks like. A mature team should be able to walk you through a live build at the end of each sprint. Written acceptance criteria are the only reliable protection against the it-was-never-in-scope conversation.

Last, plan for the handover while the relationship is still good. Ask that the repository lives under your account from the beginning, and that the documentation is refreshed in every sprint. A provider confident in its own work says yes immediately; resistance at this point says quite a lot.