Begin with relevant experience, not the length of the client list. Ask to see two or three projects that sit close to your stack, and then find out who actually wrote that code. An honest provider is happy to connect you with the engineers. Answers that name nobody at this stage almost always mean the demo work came from somewhere else.

The paperwork deserves more attention than the sales deck. Three sections matter more than the rest: hire php zend developer assignment of intellectual property, the NDA, llm integration and symfony web developer notice periods and handover. All the work product has to transfer to you once invoices are settled, along with documentation, pipelines and deployment scripts. Watch for any clause that leaves reusable components outside the transfer, because that is often the part you cannot replace later.

Ask how they estimate. An honest estimate arrives with a list of assumptions, a breakdown per feature and a best case and a worst case. A fixed price only makes sense when the requirements are stable and documented; in any other case the provider pads the number and you fund the buffer regardless. A time-and-materials model shifts that risk to you, so it demands visible weekly reporting and a spending cap.

The delivery process beats the number of developers. Ask how a new requirement enters the plan, who defines done and what the QA setup looks like. A mature team can show you running software rather than status reports. Acceptance criteria in writing remain the only reliable protection against an argument at delivery time.

Before signing, plan for the handover before it becomes urgent. Ask that the repository sits in your organisation from the beginning, and that documentation is written as you go rather than left to the end. A vendor with nothing to hide will agree quickly; resistance at this point tells you most of what you need to know.