&gt; Should I focus on one language and become really good at it or work in multiple languages and stay mediocre?<p>Both.<p>Master one, but learn enough to be able get around with the others. Also, learn <i>the language</i>, not just the tools or the new and shiny things. Tools and frameworks come and go, but the language itself will always progress.<p>&gt; I feel like I am not doing much designing and not really learning a lot.<p>Work-related code, especially the monolithic, enterprise-y variants, isn&#x27;t the best place to try something new. Try contributing to open-source projects. They&#x27;re always in need of additional hands and move relatively fast enough that new stuff comes out regularly.