Begin with domain experience, not the size of the portfolio. Request two or three engagements that match your domain and your stack, and then find out which engineers actually built it. An honest provider is happy to connect you with the engineers. Answers that name nobody at this stage almost always mean you are talking to a reseller.

The agreement warrants more attention than the sales deck. Three clauses do most of the work: assignment of intellectual property, non-disclosure, and notice periods and handover. Every artifact must transfer to you once invoices are settled, along with documentation, pipelines and deployment scripts. Look closely at wording that leaves so-called reusable libraries in the vendor's hands, because that is often the dependency that makes switching painful.

Ask how much does it cost to build an app they estimate. A credible estimate arrives with a list of assumptions, laravel vs .net comparison a task-level breakdown and next js development services an explicit range. A fixed-price contract works only when the specification is complete; otherwise the vendor pads the number and you fund the buffer regardless. A time-and-materials model shifts that risk to you, so it requires a cap, regular demos and transparent reporting.

Process matters more than team size. Ask how a new requirement enters the plan, who signs off on a feature and what the QA setup looks like. A team can demonstrate a live build at the end of each sprint. Clear, written acceptance criteria remain the only reliable 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. Require that the repository sits in your organisation from day one, and that a readme and architecture notes are kept current as the code changes. A vendor with nothing to hide accepts it without argument; a long negotiation over it says most of what you need to know.