Microservices Architecture

Gui Alvarenga - June 13, 2023

What Is Microservices Architecture?

A microservice-based architecture is a modern approach to software development that breaks down complex applications — sometimes called monolithic applications — into smaller components that are independent of each other and more manageable. The approach has gained popularity because of the advantages it brings to agile software development and application security.

In this post, we’ll explore the core concepts and benefits of microservices architecture. As a first stop in our journey, let’s consider the origins and history of microservices.

The Evolution of Microservices

Traditionally, software developers would build applications using a monolithic architecture. Following this approach, all of an application’s components are tightly integrated into a single, large unit. This results in several limitations, including challenges in scalability, maintainability, and deployment.

As systems built upon this approach grew in size and complexity, these challenges became increasingly difficult to manage. Building new features, fixing bugs, and maintaining the application became more and more time consuming and resource intensive.

Microservices architecture emerged to address these challenges by providing a more flexible and scalable way of building software applications. With a microservices architecture, a software application comprises loosely coupled and independently deployable services that communicate with each other using lightweight protocols. Let’s look more closely at what’s involved in this approach.

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Key Characteristics of Microservices Architecture

An application built on a microservices architecture has:

  • Loosely Coupled Services: Each microservice is designed to be independent and self-contained.
  • Single-Responsibility Principle: Each microservice focuses on just one responsibility or domain. This ensures that each microservice remains easy to understand and maintain.
  • Independent Deployment: Individual microservices can be deployed, updated, and scaled independently of one another, which reduces the risk of system-wide failure at any stage. In addition, independent deployment simplifies the process of updating specific parts of an application.
  • Decentralized Governance: With teams working on different microservices, each team has the autonomy to choose the most suitable technologies and tools for their microservice’s specific requirements.
  • Fault Isolation: If one microservice experiences a failure, this does not necessarily lead to the failure of the entire application. This promotes overall application resilience, as many parts of an application remain available while the team works to restore the failing microservice.

Microservices Architecture vs. Service-Oriented Architecture (SOA)

Microservices architecture is often compared to service-oriented architecture (SOA). SOA is a related approach to software design, with some key differences. Both architectures emphasize modular design, but they differ in terms of granularity, deployment, and inter-service communication.

SOAs are typically coarser-grained, with services that may be responsible for multiple functions. This is in contrast to microservices, which are more granular and lightweight, each focusing on their respective responsibilities. Also, applications built on SOA often deploy services together as part of a single, larger application.

Lastly, SOA often uses an enterprise service bus (ESB) for communication and data transformation between services, while microservices typically communicate through messaging queues or lightweight protocols like HTTP with REST APIs.

APIs are fundamental to microservices, allowing them to communicate while remaining decoupled from one another. The use of APIs, as opposed to a central ESB (as in SOAs), prevents dependence on a single point of failure.

Containerization is another essential aspect of microservices architecture that SOAs lack. Containerization and orchestration technologies (like Docker and Kubernetes) let teams package and deploy their microservices in isolated environments. Containerization brings portability, scalability, and resource efficiency to the deployment of microservice-based applications.

Learn More

Read our post comparing service-oriented architectures with microservices architecture to further understand the differences.  Read: SOA vs Microservices

Benefits of Adopting Microservices

What are the benefits of adopting microservices?

The key characteristics of a microservices architecture translate very clearly to benefits, which include:

  • Scalability: Because microservices can be scaled independently, your organization can allocate resources efficiently based on the demands of each service. This granular control over which microservice resources to scale up (and down) can yield more optimal resource allocation.
  • Flexibility: The decentralized governance of the microservices approach increases the freedom afforded to developers and their teams. This flexibility to choose the best tools and technologies as needed lets developers work more quickly, unhampered by technology decisions from other teams, thereby fostering innovation and adaptability.
  • Faster Time to Market: Changes in one microservice don’t require a full system rebuild and deployment. When microservices can be independently deployed, you get faster delivery of new features and updates.
  • Easier Maintenance and Updates: The single responsibility principle makes it simpler for developers to understand, maintain, and update individual microservices. They can focus on the microservice for which they’re responsible, using the microservice’s API as the contract through which other microservices will interface.
  • Resilience: Fault isolation helps ensure that the failure of a single microservice doesn’t bring down the entire application. This promotes system reliability and improves availability and uptime, leading to bottom-line benefits for your organization as a whole.

A microservices architecture also presents some advantages over a monolithic architecture in terms of application security as well:

  • Isolation: Because each microservice runs in its own isolated environment, an exploited vulnerability in one service does not necessarily result in the compromise of other services. This isolation potentially limits the blast radius of an attack.
  • Fine-Grained Access Control: As separate entities, microservices can have specific authentication and authorization policies based on each one’s unique needs and requirements.
  • Easier and Faster Patching: Because microservices can be independently updated and deployed, the discovery of a vulnerability in a microservice can quickly be handled with immediate patching and redeployment of that service. There is no need to take down, patch, rebuild, and redeploy the entire application.

Although a microservices architecture brings certain security advantages, there are a couple of weaknesses to consider. Specifically, the distributed nature of microservices and the increased number of inter-service interactions might increase an application’s surface area for attack.

Best Practices to Secure Microservices

To secure your microservices, follow these best practices:

  • Implement API Security: As the interface between microservices (east-west traffic) and, at times, for external requests (north-south traffic), APIs must be secured through robust authentication, authorization, and input validation mechanisms.
  • Use TLS: Data in transit to and from microservices must be encrypted to prevent unauthorized access or tampering.
  • Incorporating Zero Trust principles: Incorporate zero trust principles to secure service-to-service communication. Assume that no microservice can be trusted by default. By applying strong authentication and authorization methods, you can ensure that only legitimate microservices can communicate with one another.
  • Implement Monitoring and Logging: Continuously monitor and log service-to-service interactions. This will enable you to detect and respond to potential security incidents effectively.
  • Incorporate Container Security Tools: These container security tools ensure that containers are configured correctly and are regularly scanned for vulnerabilities, providing an additional layer of defense.

How CrowdStrike Can Help

Incorporating container security tools like CrowdStrike Falcon® Cloud Security can significantly bolster the security posture of applications built on a microservices architecture. The platform provides detailed insights into your cloud workloads, containers, images, registries, and libraries, enabling rapid and precise detection, response, and investigation of threats. This ensures no aspect of your cloud environment goes unmonitored.

CrowdStrike Falcon® Cloud Security seamlessly integrates with CI/CD workflows to provide robust security without hindering DevOps speed or performance. By leveraging these capabilities, organizations can enhance the security of their microservices-based applications.

To learn more about the best approach to secure your microservices architecture and cloud infrastructure specific to your organization, schedule a free CrowdStrike Cloud Security Health Check.


Guilherme (Gui) Alvarenga, is a Sr. Product Marketing Manager for the Cloud Security portfolio at CrowdStrike. He has over 15 years experience driving Cloud, SaaS, Network and ML solutions for companies such as Check Point, NEC and Cisco Systems. He graduated in Advertising and Marketing at the Universidade Paulista in Brazil, and pursued his MBA at San Jose State University. He studied Applied Computing at Stanford University, and specialized in Cloud Security and Threat Hunting.