From my experience, it really helps to look at the full spectrum of web development services. You’ll want solid UI/UX design, reliable front-end and back-end development, and sometimes even DevOps support if you expect your platform to scale. I came across this guide recently, which gives a clear overview of the main services you might need: https://weelorum.com/services/web-development-services/. It was really useful for planning a project and understanding what to prioritize.
