Is it an issue that Codesmith only teaches Javascript?

Not at all no! There are two paths for jobs: 1. Smaller company that is looking for existing knowledge of a specific stack. JavaScript w/React (frontend) and Node (backend) is a pretty board coverage for a lot of companies, like agencies. 2. Larger companies that are more language agnostic, because they expect to train you on their stack and frameworks - often because they are so complex and large that knowing a language might not even help much. So by focusing on JavaScript only you are losing out on non-JS smaller companies, but for this bucket you are better off being stronger in one framework than weaker in two.