Record-based error responses

// Verbose error class
public class ErrorResponse {
    private final int code;
    private final String message;
    // constructor, getters, equals,
    // hashCode, toString...
}

public record ApiError(
    int code,
    String message,
    Instant timestamp
) {
    public ApiError(int code, String msg) {
        this(code, msg, Instant.now());
    }
}

📏

Concise

Define error types in 3 lines instead of 30.

🔒

Immutable

Error data can't be accidentally modified after creation.

📋

Auto toString

Perfect for logging — shows all fields automatically.