My passion is the application programming interfaces and data exchange. Ever since I learned about the possibility to combine several services together for a quick implementation of powerful solutions, I can not imagine how we can do without it. I have designed several SOA-based projects, both consumer and producer services. My latest work is the backend part of service https://icons8.com/ It has multi-layered RIA architecture and uses XML/JSON-RPC services https://api.icons8.com/ alongside with 12 other online services through HTTP: payment systems, analytics systems, online storages, media processing and other. In my practice I encountered great difficulties in using a variety of third-party producer services, which arise from the fact that services may become unstable and slow or even fail. I solve them all using polling and pushing, multi layer cache, queues, repeating retries, and other techniques.