It's that time of year, when the Advent of Code goes live. This is a daily coding contest that starts the first of December, with a new exercise released each day leading up to Christmas. You can still join in, and even go back and look at previous years (2019, 2018, 2017, 2016) and go through them. It's a good exercise for your mind.
To be fair, I've never completed the challenge in any year. Usually life gets in the way, and I get distracted. I've gotten through 15-20 in some years, but often the time required to work through the complex algorithms gets me a little discouraged. I'm not a 10x programmer, but I try.
One thing I've done most years is to try and work through the problems in multiple languages. Typically my approach has been to try and solve each item three times, using T-SQL, Python, and PowerShell. I find it interesting to compare the languages and see how to handle the test data and also get the solution to work in each environment. I also think it's neat to start with a different language each day.
If you want to stretch your programming mind and have some fun, give the challenge a try. Posting your solutions to a blog or even open a GitHub repo (or other VCS platform). It's a good way to showcase your knowledge, at whatever level it is. You might even learn something if others comment on your solutions.