This year Firebird Conference  (October 17-19, Berlin) is devoted to the Firebird 4 features (in Day 1) and to the advanced performance and development topics (Day 2-3).
The special focus of the conference is the very big databases.
The speakers are Firebird core and driver developers and industry experts from IBSurgeon, IBExpert, RedSoft, and IBPhoenix.

The detailed schedule is available here: https://firebirdsql.org/en/firebird-conference-2019/