Begin with proven experience, not the length of the client list. Ask for three or four case studies that sit close to your technology stack, and then find out who actually wrote that code. A serious vendor will put you on a call with the tech lead. Evasive answers at this stage generally mean the delivery team is not the team you were shown.
The agreement deserves a slower read than the pitch. A few clauses carry most of the weight: assignment of intellectual property, laravel development company confidentiality, and notice periods and retail software development handover. Every artifact must transfer to you as it is paid for, along with documentation, pipelines and deployment scripts. Watch for wording that keeps reusable components with the vendor, because that is often exactly the piece that locks you in.
Find out how the estimate was built. A serious estimate comes with a written set of assumptions, a breakdown by feature or module and a range rather than a single number. A fixed price vs time and materials price works only when the specification is complete; when the scope is still moving the supplier adds a risk premium and you pay for it anyway. Time and materials puts the risk on your side, so it needs a sprint cadence, demos and a budget cap.
The delivery process beats the number of developers. Ask how change requests are handled, who defines done and how quality assurance works. A team can show you a working build every one or two weeks. Acceptance criteria in writing are the practical protection against the it-was-never-in-scope conversation.
Finally, consider the day you no longer need this vendor while the relationship is still good. Insist that the code repository lives under your account from the first commit, and that documentation is written as you go rather than left to the end. A partner who is comfortable with this says yes immediately; resistance at this point reveals most of what you need to know.