Start with domain experience, not the size of the portfolio. Ask for a couple of projects that sit close to your stack, and then find out whether those engineers are still with the company. A serious vendor is happy to connect you with the people who would work on your project. Evasive answers at this stage generally mean you are talking to a reseller.
The contract deserves more attention than the sales deck. A few clauses carry most of the weight: intellectual property assignment, non-disclosure, and notice periods and handover. Every artifact has to transfer to you as it is paid for, including documentation, pipelines and deployment scripts. Watch for fintech software development wording that keeps framework code outside the transfer, as it is usually the part you cannot replace later.
Find out how the estimate was built. A credible estimate is accompanied by a written set of assumptions, a breakdown by feature or module and an explicit range. A fixed-bid deal only makes sense when the scope is genuinely frozen; when the scope is still moving the supplier prices the risk in and you pay for it anyway. Time and materials puts the risk on your side, so it demands visible weekly reporting and a spending cap.
The delivery process matters more than team size. Establish how ai changes software development a new requirement enters the plan, who writes the acceptance criteria and what the QA setup looks like. A mature team will be able to show you a working build every one or two weeks. Clear, written acceptance criteria remain the only reliable protection against endless rounds of rework.
Before signing, consider the handover before it becomes urgent. Ask that the repository sits under your account from day one, and that documentation is written as you go rather than left to the end. A vendor with nothing to hide says yes immediately; resistance at this point says a great deal.
