How Microservices Work

We have all heard the word microservices and how it has helped major companies create larger, more complex applications that are better developed and managed as a combination of smaller services. When applying for a software development role, the phrase “designing and developing microservices” is sure to be on the list of responsibilities and objectives. But what is microservices and how does it work?

To understand the term microservice, also referred to as “microservice architecture” I do believe we need to go back to how applications were built before the term became so popular.

Before Microservice
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Traditionally, software developers created and maintained large monolithic applications. Most enterprises start by designing their infrastructures as a single monolith or several tightly interdependent monolithic applications. With monolithic architectures, all processes are tightly coupled and run as a single service. This implies that if one process of the application encounters a spike in demand, the entire architecture must be scaled. Adding or improving a monolithic application feature becomes more complex as the code base grows. This complexity makes upgrades a time consuming and expensive process and makes it difficult to execute new ideas. Monolithic architectures add risk for application availability because many dependent and tightly coupled processes increase the impact of a single process failure.

Microservices solve these challenges of monolithic systems by being as modular as possible. In the simplest form, they help build an application as a suite of small services, each running in its own process and are independently deployable.

What are Microservices?
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Microservices also known as the "microservice architecture" is an architectural style that structures an application as a collection of loosely coupled services, each of which implement business capabilities. The main idea behind a microservice architecture is that applications are simpler to build and maintain when broken down into smaller pieces that work seamlessly together. When using microservices, you isolate software functionality into multiple independent modules that are individually responsible for performing precisely defined, standalone tasks like search, reservation, billing, tax calculation, etc. This approach increases flexibility for example, updating the code of a single function without having to refactor or even redeploy the rest of the microservices architecture.

It also enables an organization to evolve its technology stack, scale and be more resilient with time. Microservice architecture advocates for developing a single application into a collection of loosely associated services. These units also enable the continuous delivery and deployment of large, monolithic applications with minimal need for centralization. These modules communicate with each other through simple, universally accessible application programming interfaces (APIs).

Benefits of Microservices

Greater Agility

They support the separation of responsibilities critical for building highly scaled applications, allowing work to be done independently on individual services without impacting the work of other developers in other groups working on the same overall application.

Faster Defect Isolation

When a test fails or service goes down, developers are able isolate the issue or spin up another component while the rest of the application continues to function independently. This capability gives developers the freedom to develop and deploy services as needed, without having to wait on decisions concerning the entire application.

Relationship to the Business

Microservice architectures are split along business domain boundaries, organized around capabilities such as billing, reservation, etc. This increases independence and understanding across the organization. Different teams can utilize a specific product and then own and maintain it for a lifetime.

Drawbacks of Microservices

Increased Complexity

Microservices are a much more complicated system, and the learning curve can be steep to climb. The architecture brings additional complexity as the developers must mitigate fault tolerance, network latency, and deal with a variety of message formats as well as load balancing. The microservice architecture is not always the best solution for an application. For some it might be too complex than what is required.

Greater Security Risks

Because microservices will exist through different environments on different running machines with different API call, they offer more points of contact to get in and damage the system.

What you need to know

Microservices is a strategy that is beneficial to the code development process, and overall business organization strategy. Microservices help organize teams into units that focus on developing and owning specific business functions. This granular focus improves the overall business communication and efficiency. Though microservices do present a host of challenges, they are easier to build, test, deploy and update compared to monolithic apps. This approach allows business to react faster to new demands as different parts of the development team can work concurrently on products, in an agile manner, and deliver value to customers immediately.