An estimate that arrives instantly is a bad sign. Any serious team responds with a list of questions: about who owns the data and next js vs laravel performance what happens on failure. A provider that commits to a figure without asking anything is probably guessing, and that guess becomes a change request later — at your expense.
Be wary of a mismatch between the people you meet and the developers actually assigned. Request specific people rather than roles in the agreement, with wording about substitutions. A vendor that will only describe abstract roles and refuses to name people is preserving its own flexibility at your cost.
Ask for commit-level visibility from the first week. A team that delivers nothing difference between laravel and symfony demos is inviting you to accept a black box. Daily commits tell you how many people are really working far better than a slide deck. This extends to the automated test suite: if it does not exist, quality claims are just talk.
Loose wording in the contract around intellectual property is not an oversight. The document must state explicitly that all deliverables transfer to your business upon settlement of the relevant invoice. Also check the governing law and how payments are structured: a request for most of the money up front with no deliverable attached eliminates your only leverage.
Lastly, swift development services pay attention to how they communicate. Confirm how many hours there will be each day, which person is expected to answer your questions and how quickly. Four hours of overlap generally works; no overlap stretches every clarification into a day of delay. Sloppy written English in the sales phase does not improve once the work starts.