Begin with domain experience, not the size of the portfolio. Ask for two or three projects that match your stack, and then find out which engineers actually built it. A solid partner will put you on a call with the people who would work on your project. Answers that name nobody at this stage almost always mean the demo work came from somewhere else.
The agreement deserves a slower read than the pitch. A few clauses carry most of the weight: ownership of the code, confidentiality, and termination and handover. All the work product should transfer to you as it is paid for, along with designs, scripts and infrastructure configuration. Look closely at language that keeps framework code outside the transfer, as it is usually exactly the piece that locks you in.
Find out how the estimate was built. An honest estimate arrives with a list of assumptions, a breakdown by feature or module and an explicit range. A fixed-price contract is only reasonable when the specification is complete; otherwise the vendor pads the number and edtech web development you pay for uncertainty either way. A time-and-materials model puts the risk on your side, so it needs visible weekly reporting and a spending cap.
Process matters more than the number of hire vue.js developers. Find out how change requests are handled, who defines done and what the QA setup looks like. A well-run team should be able to demonstrate a working build every one or vue.js software development two weeks. Written acceptance criteria are the only reliable protection against an argument at delivery time.
Last, plan for the end of the engagement at the start rather than at the end. Require that the code repository sits on infrastructure you own from the beginning, and that a readme and architecture notes are kept current as the code changes. A partner who is comfortable with this says yes immediately; hesitation here says most of what you need to know.
