Why is my Arduino running out of SRAM?

An Arduino Uno project behaves unpredictably—frequent resets, corrupted variables, or unexpected behavior. Suspecting low SRAM, especially since the Uno only has 2KB available, and the sketch uses several global arrays, strings, and external libraries.

What are the best practices to reduce dynamic memory usage and avoid fragmentation?

• How to monitor or estimate SRAM usage during runtime?

• Should String objects be avoided in favor of character arrays?

• When and how to use PROGMEM for storing large constant data?

Looking for effective ways to keep the project stable and memory-efficient.