Start with proven experience, nextjs development agency not the number of logos on the website. Request two or three projects that resemble your domain and your stack, and then find out who actually wrote that code. A solid partner is happy to connect you with the tech lead. Evasive answers at this stage generally mean you are talking to a reseller.
The agreement deserves a slower read than the pitch. A few clauses carry most of the weight: ownership of the code, the NDA, and it outsourcing germany termination and handover. Everything produced must transfer to you as it is paid for, along with designs, scripts and infrastructure configuration. Look closely at language that leaves so-called reusable libraries hire developers in russia the vendor's hands, because it is usually the part you cannot replace later.
Ask how they estimate. A serious estimate is accompanied by the assumptions behind it, a breakdown by feature or module and an explicit range. A fixed-price contract is only reasonable when the requirements are stable and documented; in any other case the provider pads the number and you fund the buffer regardless. Hourly billing shifts that risk to you, so it needs visible weekly reporting and a spending cap.
Process matters more than team size. Find out how change requests are handled, who signs off on a feature and what the QA setup looks like. A well-run team should be able to show you a working build every one or two weeks. Written acceptance criteria remain the only reliable protection against the it-was-never-in-scope conversation.
Finally, consider the handover before it becomes urgent. Require that the source repository lives in your organisation from the beginning, swift development agency and that documentation is written as you go rather than left to the end. A vendor with nothing to hide says yes immediately; a long negotiation over it says a great deal.
