@Дилян-Палаузов said in according to a user report, “performance with 120 calendars is very bad”:
Was this achieved solely by code reorganizarion,
Yes. The UI code has been changed from Loaders and ListView to ViewModel and RecyclerView, which is much more performant. Was much work on this never ending project. The next thing is to migrate to the Room database which is almost finished… and then there are about 10.000 enhancements, bugs and minor problems left.