[anotheryou]

You asked for the hardest, no good solutions to those:

- dev with low self-esteem causing social issues: problem ongoing, helping though: speaking about it, more focused tasks he can take ownership over and finish without that much communication and trouble.

- dev generally not nice to people (and not that compenent): people started avoiding him and he quit... Should not have come through the probation period, but I wasn't in change of that (see next point).

(it's also not that easy firing someone in germany btw)

- ownership of product and progress, but no say in direction (which changed every 2nd week) and not officially team lead: I quit.