It's not much about tech stack (just pick whatever your team is familiar with first), forget about performance for now (go, rust,...). Stick to industry standar

It's not much about tech stack (just pick whatever your team is familiar with first), forget about performance for now (go, rust,...). Stick to industry standards: OpenAPI, Types, FP patterns. What's more important is the architecture. It doesn't need to be complicated, but sane enough for you to break it down later in case you want to grow.