I wrote some notes after having a conversation with a long time OTP user here: https://github.com/pavlos/gen_fsm/issues/13#issuecomment-212320106

I guess that I am fairly excited about :gen_statem.

From the new documentation of gen_statem:

The gen_statem behaviour is intended to replace gen_fsm for new code. It has the same features and add some really useful:

• State code is gathered
• The state can be any term
• Events can be postponed
• Events can be self generated
• A reply can be sent from a later state
• There can be multiple sys traceable replies

Some highlights can be found here, and there you can find the link to full release notes.

I don’t know too much, but what do you think is the most exciting part about OTP 19.0?