I am more interested in seeing how complex software is built from scratch, using best practices, than any specific programming language.
Code grows, decisions get made, and practices are adopted.
I am working on my fourth iteration of what turns out to be my largest undertaking.
Step 1. Idea 2. Hack something 3. Commit, comment. 4. Hit a wall 5. Rewrite, commit, repeat. 6. Grow until new problems are discovered 7. Modules, tests, etc to avoid future problems. 8. New problems caused by complexity. 9. Go to 5.
Read this from Roblox's outage. https://blog.roblox.com/2022/01/roblox-return-to-service-10-...
My recent example - I thought I could get away with 3 VMs to run my SaaS. Yes, I could, although my storage capacity guesses were 100x less than required.