A number produced without questions counts as a bad sign. An experienced provider responds with clarifying questions before any number: about integrations. A supplier that prices with no clarification is guessing, and a guess resurfaces as a change order — and you will pay for it.
Watch for a gap between the engineers on the sales call and the hire developers in uae actually assigned. Insist on specific people rather than roles in the statement of work, with a provision covering replacement. A provider that will only describe roles and will not commit to specific engineers is reserving the option to staff you with whoever is free.
Insist on access to the repository from the start. A provider that delivers nothing between demos is inviting you to trust a black box. Visible commits tell you who is really on the project far better than a weekly report. The same applies to the automated test suite: if nothing runs automatically, quality claims remain just talk.
Ambiguous wording in the contract around code ownership is not a formality. The document needs to state in plain terms that the code, outsourcing and development insights designs and documentation belong to the client upon settlement of the relevant invoice. Look too at the governing law and which is better livewire or alpine js the milestone terms: a large upfront payment with nothing due in return for weeks removes the only leverage you have.
Lastly, examine communication. Establish how many hours the teams will share with your working day, who handles questions and how quickly. Some genuine overlap is normally sufficient; no overlap stretches each small question into a lost day. Careless writing in the early emails will not improve once the work starts.