One thing that helped me a lot was getting involved in competitive programming. Back then it was just the ACM contests but now there are multiple sites like Top

One thing that helped me a lot was getting involved in competitive programming. Back then it was just the ACM contests but now there are multiple sites like Topcoder, Codekatas, Codewars, etc. Working through different levels of challenges in different languages helps push your language and algorithm knowledge. Reading other people's solutions is also a huge help.