It's from 10 years ago but surprisingly explains exactly what the new twitter owner was referring to a day or two ago:
> Rendering even the simplest web page on twitter.com requires the collaboration of dozens of network services speaking many different protocols. For example, in order to render the home page, the application issues requests to the Social Graph Service, Memcached, databases, and many other network services. Each of these speaks a different protocol: Thrift, Memcached, MySQL, and so on. Additionally, many of these services speak to other services — they are both servers and clients. The Social Graph Service, for instance, provides a Thrift interface but consumes from a cluster of MySQL databases.
> Rendering even the simplest web page on twitter.com requires the collaboration of dozens of network services speaking many different protocols. For example, in order to render the home page, the application issues requests to the Social Graph Service, Memcached, databases, and many other network services. Each of these speaks a different protocol: Thrift, Memcached, MySQL, and so on. Additionally, many of these services speak to other services — they are both servers and clients. The Social Graph Service, for instance, provides a Thrift interface but consumes from a cluster of MySQL databases.