What technologies or languages in your opinion should a full stack developer know.

Nodejs, angularjs

If you call yourself a full stack developer you must know at least one backend language in which you are thorough enough to write services along with keeping very important things in mind like security, authentication etc. One JavaScript framework is necessary and HTML/CSS is kind of understood here. Also at least one sql and no-sql database is must. These are the bare minimum requirements of being a full stack dev. To be a good full stack dev there is much more you should be familiar with like basic devops, scaling, deployment/testing tools, and mobile apps is a huge plus.