Ask HN: Any recommendations for full-service web dev vendors?

I have some tech experience and a product idea that I think is economically viable. I don’t want to build/run it myself though. My ideal scenario is to hire a company that would handle all design/tech, both in the building stages and on-going maintenance, on-call, everything. Basically paying the company to be my dev team. It would be a relatively simple web application along with auth, payment, etc.

Is this realistic? Are there such companies you know of or have worked with? Toptal? Others? What is pricing like?

Much appreciated!