HackerPen - What is HackerPen?
Huntathon - Browse and submit Product Hunt Global Hackathon projects
HackerRank - HackerRank is a platform that allows companies to conduct interviews remotely to hire developers and for technical assessment purposes.
Foundler - Online hackathon weekends. Attend every other week.
Coding View - Coding View is live collaborative coding environmentdesigned for technical phone interviews. It features web version of Visual Studio Code, as well as access to real terminal. It has a built-in compiler for most popular programming languages.
Confs.tech - Open source list of tech conferences: JS / Ruby / Data etc.