Look first at domain experience, not the number of logos on the website. Request two or choosing between laravel and node js three case studies that sit close to your stack, and then ask who actually wrote that code. An honest provider will put you on a call with the tech lead. Vague answers at this stage almost always mean the delivery team is not the team you were shown.
The agreement warrants more attention than the sales deck. Three sections matter more than the rest: assignment of intellectual property, confidentiality, and exit terms and handover. Everything produced should transfer to you on payment, including documentation, pipelines and deployment scripts. Watch for custom government agency software development language that leaves so-called reusable libraries in the vendor’s hands, as it is usually exactly the piece that locks you in.
Ask how they estimate. A serious estimate is accompanied software development by industry a written set of assumptions, a breakdown per feature and an explicit range. A fixed price works only when the scope is genuinely frozen; in any other case the supplier prices the risk in and you fund the buffer regardless. A time-and-materials model moves the risk back to the client, so it requires visible weekly reporting and a spending cap.
How the work is run beats team size. Ask how change requests are handled, who writes the acceptance criteria and what the QA setup looks like. A well-run team should be able to demonstrate running edtech software development services rather than status reports. Acceptance criteria in writing remain the practical protection against an argument at delivery time.
Finally, plan for the day you no longer need this vendor while the relationship is still good. Ask that the source repository sits under your account from day one, and that a readme and architecture notes are kept current as the code changes. A partner who is comfortable with this will agree quickly; a long negotiation over it says a great deal.