What modern approaches to search for zero day vulnerabilities do you know?

Question

Information Security

Lord! I would like to hear the opinion of people who understand this issue or work in this area.
The question itself is in the title.
What modern approaches for searching for zero day vulnerabilities do you know?
For example:
-Fuzzing
-Disassembly of program code and subsequent search for errors
What other approaches or methodologies are there today? Maybe someone will recommend useful literature. Thank you!