https://docs.oracle.com/javase/7/docs/api/java/io/Serializable.html
When and why JPA entities should implement the Serializable interface?
According to the Java specification, to write an object in jvm to a file, etc., it is said that serializable must be implemented.
However, this is clearly an incorrect explanation. So far, I have never implemented serializable when putting data into redis cache, session, or RDB.
Even if you don't implement serializable, it is normally written outside the JVM memory, such as a file, so I don't understand why you need to implement this. As I said before, I've never used serializable and it's been working fine so far.