I like to understand what I'm working with
Seamless communication between designers and developers is crucial for successful products. I've always written code to have a good understanding what the developers can do and cannot do, what is easy and what is difficult, and what they need from me as a designer.

I write mostly Elixir (web projects), Rust (crypto projects), Swift (mobile projects) and JavaScript/TypeScript/React (web & prototyping).
Elixir is probably the best choice for web projects these days. Not because of the language itself, but because of the BEAM virtual machine. This thing can run millions of processes in parallel, effectively utilize all available CPU cores, if one process gets stuck, it won't affect the performance of the whole system, if process crashes, it won't crash the whole system. This system is battle tested over the last 2 decades in telecommunications, and there's probably nothing that comes even close, if you need to build highly resilient projects that can handle huge volume of traffic.

LiveView is quite a novel way of writing web applications that need reactive real-time front-ends. This is typically written in React/Vue/Angular and communicates with backend via API. But LiveView uses very different approach, where the front-end is super lightweight and any changes on frontend are streamed via sockets. It's such a great idea, that it has been replicated in pretty much all web frameworks already, including Rails, Django, Laravel, etc.

Here is a side project I've written in Elixir & LiveView called Organizer - it's basically just a todo list, but it works in realtime thanks to LiveView and sends you an email when all todos are completed. The idea is you create a todo list for someone else, share it with them, and then get notified as soon as they finish it. See
Rust is ultra-fast universal language that lets you build almost anything including whole operating systems. It's one of the modern languages combining all the goodies from various other places. It is surprisingly similar to Elixir in many ways, especially the terminology is very similar. Rust is also used to write smart contracts on Terra blockchain and Solana blockchain - this is how I started working with it.

Here is one repository with my "rock paper scissors" game for Terra blockchain:

Josef Richter 2023