Learning deep dive into linux networking [https://sysplay.in/index.php?pagefile=lnd_weekend_workshop] /system programming[https://sysplay.in/index.php?pagefile=lsp_online_training] / algo-DS etc. Mostly through online courses in second half of 2019. Wasn't that enthused about them previously, but having attended one, those are not bad and have lot of flexibility in terms of schedule and not having to travel.