The languages I think in. TypeScript is home — strict types, discriminated unions, and the satisfaction of a compiler that catches mistakes before they become bugs. JavaScript everywhere because the runtime matters. Python for ML work and scripting. Go for compiler projects, because it compiles fast and stays out of the way. Java from the enterprise trenches at Publicis Sapient and Capital One, Scala from the graduate ones. SQL because data has structure whether you model it or not.