I do a lot of coaching as part of my role as a manager and enjoy rubber-ducking and helping people solve problems & learn better ways to solve them on their own in the future.
I've done a lot of work at scale (1M+ users) with PostgreSQL and Apache Kafka using Go or Python, as well as written algorithms in C++ to support rendering of billion-triangle objects.
I will want to understand your problem, give you pointers and start from broad context so that you understand where it is, and then give more specific advice once I'm confident you can use and build on it.