Start with relevant experience, not the number of logos on the website. Request two or three projects that resemble your stack, it outsourcing russia and then find out who actually wrote that code. An honest provider is happy to connect you with the people who would work on your project. Evasive answers at this stage almost always mean the demo work came from somewhere else.
The paperwork needs a slower read than the pitch. Three sections matter more than the rest: assignment of intellectual property, the NDA, and exit terms and handover. Every artifact should transfer to you as it is paid for, including designs, scripts and infrastructure configuration. Look closely at language that leaves reusable components in the vendor's hands, since it is usually exactly the piece that locks you in.
Find out how the estimate was built. An honest estimate is accompanied by a written set of assumptions, a breakdown per feature and a best case and a worst case. A fixed-price contract only makes sense when the scope is genuinely frozen; in any other case the vendor prices the risk in and you pay for it anyway. A time-and-materials model shifts that risk to you, so it demands a sprint cadence, demos and a budget cap.
The delivery process beats headcount. Find out what happens when the scope changes, who defines done and hire web2py engineer how testing is organised. A well-run team can demonstrate a working build every one or two weeks. Written acceptance criteria are the practical protection against the it-was-never-in-scope conversation.
Finally, mvp development mistakes to avoid think about the end of the engagement while the relationship is still good. Ask that the code repository sits under your account from day one, and vue js or angular that a readme and architecture notes are kept current as the code changes. A vendor with nothing to hide says yes immediately; a long negotiation over it says a great deal.
