Over the years, I have been using Ruby, Elixir, JavaScript, and a bit of Rust, and played with other languages (Clojure, Python, etc.).
Past projects involved me in learning new, exciting domains. ERP/CRM systems, financial and legal services, e-commerce, to name a few. Every team I worked with comprised great people to learn from and sometimes to teach. Extra experience working as a “one-man army” dev, which I gained on a few projects, has enriched my technical and management skillsets.