An estimate that arrives instantly should be treated as a warning, not a service level. An experienced provider will come back with a list of questions: about users and volumes. A provider that prices with no clarification is pricing a guess, and that guess becomes a change request later — and you will pay for react native programmers for hire it.
Be wary of a mismatch between the people you meet and the people who will code. Insist on specific people rather than roles in the statement of work, with a provision that requires notice before anyone is swapped. A provider that only offers abstract roles and refuses to name individuals is keeping its own flexibility at your cost.
Ask for commit-level visibility from the first week. A team that hands over a build only at the end of each phase expects you to accept a black box. Regular commits and pull requests tell you the actual pace far better than a slide deck. The same holds for the build and deployment setup: if nothing runs automatically, assurances about quality remain nothing more than words.
Ambiguous wording in the contract around intellectual property is rarely an oversight. The contract needs to state in plain terms that all outputs produced under it belong to your mvp development company as they are paid for. Check also which is better monolith or microservices country's law applies and the payment schedule: a large upfront payment with no deliverable attached removes the only leverage you have.
Finally, examine communication. Establish how much working-time overlap there will be each day, who handles questions and performance php vs python on what response times. A few hours of overlap generally works; no overlap converts every clarification into a day of delay. Careless writing in the early emails does not improve once the work starts.
