Have I participated in integrating with external or internal services in my projects?

Yes, I have participated in integration with external and internal services in several projects. For example, I integrated REST APIs of third-party services to retrieve data, and also connected microservices within the company via HTTP and message brokers (such as RabbitMQ). I used Spring RestTemplate and WebClient libraries for integration, as well as JSON serialization through Jackson.

Example of calling an external REST API using Spring WebClient:

WebClient client = WebClient.create("https://api.example.com");
String response = client.get()
    .uri("/data")
    .retrieve()
    .bodyToMono(String.class)
    .block();
System.out.println(response);

I also implemented error handling and retries for temporary failures, which is important for reliable integration.