There are some threads here looking for advice on how to substitute the missing EEPROM on the Arduino 33 BLE and BLE Sense. I think I came up with a nice solution, but the threads are all closed so I post this in a new thread.
I wrote a library called NanoBLEFlashPrefs. It allows to store parameters and preferences persistently between program restarts and even reprogramming.
The Arduino boards mentioned above use a nRF52840 microcontroller from Nordic Semiconductor. This chip features a very simple file system for flash storage. This is used in the library to store and retrieve an arbitrary struct of preferences of your program.
Please take a look at the GitHub repository of NanoBLEFlashPrefs. Comments welcome!