An estimate that arrives instantly is a warning, monolith vs microservices not a service level. A competent team returns a list of questions: about who owns the data and what happens on failure. A vendor that prices before understanding the scope is guessing, and native app development a guess becomes a change request later — and you will pay for it.
Be wary of a gap between the engineers on the sales call and the people who will code. Insist on the names and CVs of the actual team in the statement of work, with a provision about substitutions. A provider that talks only about roles and will not commit to people is preserving the right to assign anyone it likes.
Insist on access to the repository from the first week. A provider that shows nothing between demos is inviting you to accept a black box. Regular commits and pull requests tell you the actual pace far better than any status report. This extends to the automated test suite: if nothing runs automatically, assurances about quality are nothing more than words.
Vague contract language around intellectual property is rarely a formality. The document should state explicitly that all deliverables become the property of your business upon settlement of the relevant invoice. Also check which is better laravel or ruby on rails country’s law applies and the milestone terms: a request for most of the money up front with no deliverable attached eliminates the only leverage you have.
Finally, examine communication. Ask what overlap you will share with your working day, which named person answers your questions and how quickly. Four hours of overlap is usually enough; no overlap stretches each small question into a lost day. Careless writing in the proposal rarely improves once the work starts.