I think async and aiohttp are game changes for Python 3.5. After working with Twisted callbacks for over a decade, it&#x27;s a pleasure to write async code that does not use the callback approach (granted Twisted is a mature environment with lots to offer).<p>I&#x27;ve switched to Python3.5 and aiohttp for all new web service applications. The coding style is clean, enjoyable to write, and easy to debug.<p>Plus, I&#x27;ve never once been stymied for speed. I know there&#x27;s applications out there where people expect to to be handling zillions of connections -- but the bulk of my use cases think 100 transactions per second is a huge through-put, and aiohttp handles that with ease.