“The move from a distributed microservices architecture to a monolith application helped achieve higher scale, resilience, and reduce costs” – Prime Video Tech Blog

A surprisingly forthright statement on the cost of cloud computing and the frenzied drive to microservice all the things, from Amazon no less. The headline really says it all, but let’s keep digging. They are discussing an automated video streaming quality control service.

We designed our initial solution as a distributed system using serverless components, which was a good choice for building the service quickly. In theory, this would allow us to scale each service component independently (but) the overall cost of all the building blocks was too high to accept the solution at a large scale…The two most expensive operations in terms of cost were the orchestration workflow and when data passed between distributed components…We realized that distributed approach wasn’t bringing a lot of benefits in our specific use case, so we packed all of the components into a single process…Moving our service to a monolith reduced our infrastructure cost by over 90%. It also increased our scaling capabilities.

Emphasis mine.

There is no free lunch. Doubly so in the cloud. It’s great for small projects just starting out that don’t want to manage their own infrastructure. It works well for production environments with small, predictable traffic or wildly unpredictable traffic. But if you need all the power all the time, you’re going to pay dearly for it. This also reminds us that cloud services eventually have to run on an actual computer, and moving data between processes is expensive (both time and money, especially the way AWS nickels and dimes you for every byte you move) no matter how many layers of abstraction you stack on top.