Findnlink - Find people to work with on your ideas.
Foundler - Online hackathon weekends. Attend every other week.
Founders Nation - Find or become a startup cofounder
HackHub - Host tech events and hackathons with ease 👨💻🛠
Find A Maker - find a partner for your next project
Confs.tech - Open source list of tech conferences: JS / Ruby / Data etc.