An estimate that arrives instantly is a warning, docker development services not a service level. Any serious team returns clarifying questions before any number: about who owns the data and what happens on failure. A provider that quotes before understanding the scope is simply working from a template, and the gap becomes a change request later — at your expense.
Be wary of a mismatch between the people you meet and those who eventually appear in the repository. Ask for the names and CVs of the actual team in the contract, with a provision about substitutions. A vendor that only offers a pool of resources and never names people is keeping the right to assign anyone it likes.
Require commit-level visibility from the start. A partner that delivers nothing between demos is asking you to take delivery on faith. Daily commits show you the actual pace far better than any status report. This extends to the CI pipeline: if there is no pipeline, quality claims remain unverifiable.
Vague phrasing around code ownership is never a formality. The contract needs to state explicitly that all outputs produced under it become the property of the client on payment. Look too at which country’s law applies and react custom software development how payments are structured: a request for most of the money up front with nothing due in return for weeks removes the only leverage you have.
Lastly, look at communication. Ask what overlap you will share with your timezone, llm integration who answers questions and on what response times. A few hours of overlap is usually enough; none at all converts every clarification into a lost day. Unclear written communication in the early emails rarely improves once the work starts.