A really effective way to handle nullable fields is an Optional<T> which forces the user to handle a null value for that field, this is very useful when working in a team and dealing with objects that someone else spent time creating, it won’t get rid of null but it definitely hints the user at “hey this field may be null so I should go ahead and handle this before I even get to testing my code”
Edit: You would want to implement these in your getters for fields that may return null