A number produced without questions is a bad sign. Any serious team responds with questions first: about who owns the data and what happens on failure. A supplier that quotes with no clarification is pricing a guess, and custom web development services a guess will be corrected later — at your expense.
Look out for a gap difference between livewire and vue the engineers on the sales call and the developers actually assigned. Insist on specific people rather than roles in the statement of work, with a clause covering replacement. A team that only offers abstract roles and will not commit to individuals is preserving the right to assign anyone it likes.
Insist on access to the repository from day one. A provider that shows nothing between demos expects you to accept a black box. Regular commits and pull requests show you how many people are really working far better than a weekly report. The same holds for the CI pipeline: if there is no pipeline, vue js development agency assurances about quality remain just talk.
Vague wording in the contract around code ownership is rarely an accident. The contract should state plainly that all deliverables belong end to end project development your company on payment. Check also the jurisdiction and the payment schedule: a request for most of the money up front with no deliverable attached eliminates your only leverage.
Finally, look at communication. Establish what overlap you will share with your working day, who handles your questions and on what response times. Some genuine overlap is normally sufficient; none at all stretches every clarification into a lost day. Unclear written communication in the sales phase will not improve under delivery pressure.