Cloud Native vs Microservices

Many software developers and even authoritative voices in the software industry use the terms cloud native and microservices interchangeably. While studying with the excellent book Cloud Native Spring, I decided to dig deeper into the differences between those two approaches.

The experienced Thomas Vitale emphasizes that the book is about building cloud native applications, and not necessarily about microservices. He points out that he adopts a service-based architectural style. He explains that this allows for services of any size: small, big, and everything in between. I inferred from it that a system built using the microservices-based architectural style must consist of all small/micro services.

I decided to give the matter further thought to further understand the differences, going beyond just the size of services difference. Here is what I concluded:

1. A cloud native system consists of one or more services of any size. It could be a monolith that is modular, many small/micro services, or anything in between. Microservices must consist of many small/micro services, each loosely coupled and highly cohesive, each separate and doing one thing.
2. A cloud native system must leverage the cloud. It's in the name. Microservices don't have to. They can be hosted fully on premise.
3. A cloud native system leverages elasticity, i.e. auto-scaling that comes with using the cloud as the platform. Microservices don't have to.

The cloud enabled more systems to go the microservices path, but it doesn't require systems to do that in order to leverage the benefits of the cloud, i.e. become cloud native. Going cloud native is more that just the size of each service. It's about achieving the goal of better scalability, better resilience, higher speed to market, and lower costs, using the cloud as the platform, and utilizing the practices of automation, continuous delivery, and DevOps.