What integrations have you worked with? API integrations with what?

In my practice, I have worked with integrations via REST and SOAP APIs with various systems:

• Payment gateways (e.g., Stripe, PayPal) for processing transactions.
• CRM systems (Salesforce, Bitrix24) for synchronizing customer data.
• Internal microservices via REST API for data exchange and business logic invocation.
• Integrations with monitoring and logging systems (Prometheus, ELK).

Example of REST API integration in Java using HttpClient:

HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
    .uri(URI.create("https://api.example.com/data"))
    .header("Authorization", "Bearer token")
    .GET()
    .build();

HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
System.out.println(response.body());