Controller annotations

Constructor injection - controller

Constructor injection - service

ResponseEntity return types

CREATED status on POST

Request body validation

DTO as Java record

Bean validation on DTO

@ControllerAdvice handler

Validation exception handler

@Transactional on write

@Service annotation

@EnableCaching on config

@Cacheable with value and key

@CacheEvict usage

@EnableAsync on config

@Async annotation

CompletableFuture return type

SLF4J logger declaration

Structured log format

Error log with exception

EntityNotFoundException on miss

Bucket4j dependency

ConcurrentHashMap for buckets

getRemoteAddr() for client IP

No direct X-Forwarded-For

429 on rate limit exceeded

OncePerRequestFilter for logging

Structured request log fields

Exponential backoff formula

InterruptedException handling

Max retries enforced

Bandwidth.classic with Refill.greedy