Foundler - Online hackathon weekends. Attend every other week.
Goodreads - See what your friends are reading.
Confs.tech - Open source list of tech conferences: JS / Ruby / Data etc.
LibraryThing - A home for your books.
HackHub - Host tech events and hackathons with ease 👨💻🛠
GoodBooks.io - Largest curated collection of 8,500+ book recommendations.