Dowwie

Learn how to really use a relational database, relational data modeling, and SQL. Not knowing of their capabilities may lead you to unnecessarily complicating your tech stack. You can go a really long way with just this domain of expertise. From there, do the same with whatever key-value store interests you (for me, it's Redis). Python isn't known for high performance but when a django web app uses a cache and relational database effectively, it can achieve a very acceptable peformance. Case in point: the Zulip chat platform: zulipchat.com.

Aside from the database domain, I really enjoy using Rust and recommend it as the next language for anyone to learn, but only after taking time for in-depth relational database training. :).

vishnu_ks
Since Zulip was mentioned, I like to point folks who are interested more to the Architecture overview docs of Zulip. The docs has details on how Zulip make use of Django, PostgreSQL, Redis, Tornado, RabbitMQ etc for building a scalable chat application.

https://zulip.readthedocs.io/en/latest/overview/architecture...

Zulip is Open Source, so do take a look at our GitHub page if you folks want to dive deeper or want to get some hands on experience. We are a welcoming community to new contributors :)

https://github.com/zulip/zulip

Disclaimar: I work at Zulip.