I have never had the luxury of one stack.
Eight companies, seven industries, and a consultancy of my own since 2020. Telecom test automation in C and Erlang. Payment gateways and insurance systems in Java and Spring. A Django microservice fronting core services at FreshBooks. Industrial AI, event ticketing and construction ERP now — Python, Django and FastAPI on one side, TypeScript, React and Next.js on the other.
Different domain, different stack, same job: get useful fast, then ship something the next person can maintain.