aiohttp is asynchronous HTTP client and server library built on top of asyncio. The library allows to write user friendly code which looks like well-known linear one (requests library for client and Django/Flask/Pyramid for server) but utilizes the power of non-blocking sockets and supports websockets natively. The intro describes basic programming patterns for both client and server API as well as more advanced techniques. Tips and tricks for writing asyncio-based code are included as well. The main target of the talk is displaying an alternative to people who want to avoid classic WSGI frameworks (Django/Flask/Pyramid etc) limitations but found Twisted and Tornado too cumbersome. Dive into aiohttp usage with the library author.