In addition to the many other suggestions here, there's plenty of ways to practice improving your current apps. Some examples I can think of from your descripti

In addition to the many other suggestions here, there's plenty of ways to practice improving your current apps. Some examples I can think of from your description: How are you doing deployments right now? Do you have a bunch of manual steps that have to happen in the right order, can you do a rollback quickly if you have to? Try learning some better deployment technologies that fix those problems. You might not have been bitten hard by any of them yet, but you never know when it could happen. How about logging and monitoring, have you integrated with any tools that could allow you to monitor performance and error rates from all of your sites? That's also worth doing if you haven't already. Are you using source control best-practices and CI/CD systems? Are your repos set up such that a new contributor could get onboarded to them easily? If not, do that. Try spinning up a VM or something and getting your repos set up on them, and fix or clarify as many manual steps as possible.