Prefer data structures

Use Data Structures with a specific name and structure instead of anonymous or generic instances.

When you pass around raw maps, lists, or generic objects, your code becomes unclear and harder to maintain. A Map<String, Object> might work quickly, but six months later nobody remembers what keys exist or what values they hold. Giving data a name and structure makes the code self-explanatory and much safer.

Bad example:

Map<String, Object> user = new HashMap<>();
user.put("id", 42);
user.put("active", true);

What is inside this map? You need to dig into other parts of the code to find out. Adding or changing fields becomes error-prone.

Better approach with a record:

public record User(int id, boolean active) {}

Now the structure is explicit, concise, and immutable by default. You get equals, hashCode, and toString for free. The compiler helps you, the IDE can auto-complete, and new developers immediately understand what a User is. You can still extend it later with methods for validation or domain logic if needed.

Every time you commit, check if you used a raw collection or anonymous object where a record (or class) would communicate intent better. This simple step will make your code cleaner, easier to refactor, and much less error-prone.