5 Spring Boot Patterns That Separate Senior Developers From Juniors

 1. Configuration Properties Binding over Scattered Injections@Value

What juniors often do:

@Value("${app.name}")
private String name;

@Value("${app.timeout}")
private int timeout;

@Component
@ConfigurationProperties(prefix = "app")
public class AppProperties {
  private String name;
  private int timeout;
  // getters and setters
}

# application.yml
app:
  name: MyApp
  timeout: 30

2. Constructor Injection over Field Injection

What juniors often do:

@Autowired
private OrderRepository orderRepository;

What seniors do:

@Service
@RequiredArgsConstructor
public class OrderService {
    private final OrderRepository orderRepository;
}

3. Using for Environment-Specific Beans@Profile

You wouldn’t hardcode your database password, right?

But what about behavior?

What juniors often do:

if (isProd) {
    sendRealEmail();
} else {
    logEmail();
}

What seniors do:

@Profile("prod")
@Service
public class RealEmailService implements EmailService {
  public void send(String msg) {
    // actual logic
  }
}

@Profile("dev")
@Service
public class MockEmailService implements EmailService {
  public void send(String msg) {
    log.info("Mock email: " + msg);
  }
}

spring:
  profiles:
    active: dev