Scala

It is more idiomatic in scala to use Option, i.e. Some and None instead of null. Using Some(null) instead of None defeats the entire purpose of Option. However, there might be certain scenarios where this is a legitimate approach, such as when dealing with Java-based libraries, to improve compatibility.

Carefully consider whether using Option with null is necessary before doing so.

It is suggested that you do not use wildcards in the import statements. This defeats the entire purpose of properly packing the code into different classes and packages. Rather, import only what you need.

Scala allows you to import entities from same package in separate statements. However, it is generally recommended that you group such imports together. Doing so makes the code more readable and easier to navigate.

A class cannot extend an object thereby making the final modifier redundant. It is therefore recommended that you drop the said modifier.

Methods with return type Option should either return Some if a suitable value exists or None if not. Returning null from such methods can have unintended side effects.