Although headless and microservices architecture share a lot in common when it comes to instilling operational independence and development flexibility, the specific development approach each one entails does them suited to different use cases.
Let's look at a breakdown of the similarities and differences between headless and microservices architecture, along with guidance on which to use to best support your application.
What is headless?
In application development, headless architecture is a software design strategy that separates an application's front end from the back end. For instance, you could build a headless content management system that lets the interface users see when they log in to operate separately from the interface that handles back-end concerns like data storage and content publishing processes.
A headless architecture separates components at the code level, letting developers modify and deploy the application's front end without directly affecting operations in the back end. Both the front- and back-end components of the application still interact with each other, and both need to be present for the application to maintain full functionality. However, the code for each end of the application can operate independently and be updated without wholly disrupting the other.
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What are microservices?
Microservice application development is an approach to building software in which large applications are split into independent modules of function-based components. For example, a typical microservice-based application might encompass one service responsible for connecting to a database, another that processes data after it is pulled from the database and a third that transmits the processed data to the front-facing UI. Meanwhile, another independent service might handle specific front-end functions like serving up video or HTML-based content.
Headless vs. microservices
There are many shared concepts that sit behind microservices and headless development as well as some benefits:
- Simplified development experiences. Developers can make changes to one part of the application without having to modify or recompile the entire application.
- Easier deployment processes. Individual parts of the application can be deployed separately.
- Higher levels of resiliency. Individual component failures can be isolated, which lets other parts of the application remain operational.
Although they share core characteristics, headless and microservices are not the same architecture. They are profoundly different in several key respects, such as their degree of modularity, degree of decoupling, and types of design and management challenges.
Structure and management
Microservices provide modularity by breaking applications into many different pieces rather than just splitting the front and back end like headless architecture does. In this respect, microservices arguably offer a higher degree of flexibility and modularity than a headless architecture design. However, microservices also feature a deeper level of decoupling than headless architecture, which means that a microservices-based architecture often represents a more daunting and complex management challenge than the headless approach does.
Microservices typically interact over the network using internal API calls. This means that microservices belonging to the same application can be deployed on different services. With headless architecture, both the front end and back end typically must run on the same server. There is no rule that says you can't build a headless architecture where your front end and back end use internal APIs to interact in a "microservice fashion," but that approach is less common.
In general, the microservice-based approach requires that architects and developers determine exactly which microservices to build, which is not an easy task. Software teams must carefully assess how to achieve the best balance between application complexity and modularity when designing a microservices application. There are also few standards or guidelines that dictate the exact number of individual microservice modules an application should embody.
While including too many microservices can add unnecessary development and operations overhead as well as compromise the architecture's flexibility, a headless architecture is much easier to design since there is still a clear definition between the front and the backend. Division of responsibilities will remain much clearer, and the relationship between components is less likely to get lost in translation.
A single microservice-based application can easily represent dozens of individual services running across a complex cluster of servers. Each service must be deployed and monitored separately because each one could impact the performance of other microservices. It might not be easy to trace that as the web of services grows and changes over time.
As a result there are generally many more moving parts to contend with in a microservices application than a headless application. Headless only aims to separate the application's front-end and back-end functionality.
Choosing between headless and microservices
When deciding whether to adopt a headless or microservices-based architecture design approach, first consider how much modularity your application needs. Using a microservices architecture makes sense if the related applications are likely to experience high degrees of scaling due to constant fluctuations in demand. However, a headless architecture may serve you better if the application does not need to scale up and down frequently but could simply benefit from a reasonable separation of concerns.
Also consider how many development and operations resources are realistically available to your software team at any given time. Headless applications can be simpler to implement and manage than microservices, making them a good fit for organizations that can't devote as many resources to application implementation. However, organizations that do have sufficient access to resources could be selling themselves short by not pursuing the microservices approach when they are in a reasonable position to do so. Headless simply cannot match the sophisticated level of component segmentation provided through microservice-based development.