Monolithic to Microservices: Advantages, Disadvantages, and the Real Reason Companies Migrate

monolithic-to-microservices

When developers discuss monolithic-and microservices-based architectures, a third “M” word tends to appear: migration.

Microservices grew in popularity from 2014 on—especially as companies like Netflix, Amazon, and Etsy made microservices a focal point both for their architectures and for their long-term abilities to iterate. Migration became the headline topic. If you were on a monolith, how were you going to migrate? When? It had to be soon.

But as the microservices trend became a norm and many companies—across different industries and scales—tried out the approach, it often failed to live up to its hype. Many companies, including teams Amazon and Uber, have shifted away from a microservices architecture.

As with many technology trends, microservices seem destined to neither flare out as a fad nor take over as a universal expectation. Backed by the experiences of others, companies can now rigorously evaluate the advantages and disadvantages of each architecture approach and see beyond the false dichotomy the two options imply. For many companies, the best option might be neither.

What is monolithic architecture?

Monolithic architecture describes a model of software design that involves building an application as a single, unified unit. The monolithic approach is traditional—dating back to mainframe-focused software development in the 1950s and 1960s—and many developers and companies have encountered monolithic applications and their limitations.

Monolithic architecture is a traditional model for building software that’s entirely self-contained. Monolithic applications operate off of one codebase that handles the front- and back-end experiences of your ecommerce storefront. Updating a single component requires you to access your storefront’s entire codebase before deploying an updated version of your application.

Advantages of monolithic architecture

Monoliths have a bad reputation, but there are still advantages to a monolithic design. But these advantages are often only seen after companies try a new design.

  • Reduced overhead: Especially compared to a microservices approach, a monolithic architecture can require relatively little overhead. Monoliths can often be simpler than other approaches because the consolidated nature of a unified application tends to mean less management, coordination, and orchestration.
  • Maintenance: Because all components of a monolithic application are housed in a single, unified codebase, debugging and testing tend to be more streamlined. When there are issues, developers often have an easier time tracing flaws, discovering bugs, and finding dependencies.
  • Simplicity: Monoliths can offer a surprising level of simplicity for businesses in their infancy that are looking for simpler code management and deployment methods. However, this benefit quickly evaporates when your business requirements evolve and become more sophisticated.

Disadvantages of monolithic architecture

The disadvantages of monoliths are what have driven much of the interest in microservices and other architecture designs. Other designs are often counterposed to the disadvantages of monoliths, but companies need to be wary of assuming the issues they might be encountering are an inevitable part of monolithic architecture.

  • Inefficient development workflows: Monolithic applications, because they’re designed as a single unit, tend to create tightly coupled relationships between different components. Often, that results in developers feeling frustrated because dependent components supported by other teams can frequently block their development work.
  • Expensive scalability: Monolithic applications can still benefit from cloud-based resource allocation, but scalability tends to be expensive because resources have to flow through the entire application. Even if increased strain resulting from an uptick in users is focused on a particular part of the application, developers can’t allocate resources to that component alone.
  • Shared technologies: In a monolithic design, applications share the same languages and primitives and tend to reuse much of the same tooling. The requirement to share these technologies sometimes results in inefficiencies as teams rely on technologies they wouldn’t have otherwise chosen. For example, if the main application is built in a stable, well-supported framework, the application’s fundamental features might benefit, while the ability to rapidly develop new features and experiences might suffer.

What is microservices architecture?

Microservices architecture describes a model of software architecture design that decomposes the components of an application into separate isolated services that communicate with each other via API.

The three defining characteristics of microservices are:

  • Individual technology stacks: Each service has its own codebase that can be managed by smaller development teams.
  • Reliance on communication protocols: Each service communicates via an API layer, which is especially useful as the number of applications or services you’re using grows.
  • Organized by business capability: The separation of services is decided by business capability, so each service is responsible for a relatively small portion or function of the overall application.

In the years since 2015, when companies were winning awards for microservices work, more organizations have adopted the design and, in many cases, found more disadvantages than anticipated. In some cases, companies have migrated back to a monolithic design or to a different architecture altogether.

Advantages of microservices architecture

The advantages of microservices architecture design come primarily from how it separates and isolates services. This emphasis on separation creates a loose coupling between different parts of an application at a level even a well-designed monolith likely can’t achieve.

  • Flexibility and agility: By separating an application into services, companies make it easier for development teams to update each service. Development teams can build new features and functionalities without worrying about other teams and deploy them without disturbing other parts of the application. In theory, this flexibility means teams can turn around updates rapidly as well as experiment and iterate more often over time.
  • Autonomy: Because each service is separate and uses a distinct codebase, development teams can be more autonomous and worry less about coordinating work across teams. Development teams can pick their preferred frameworks, languages, and tooling, and they can deploy their work at a pace that suits them.
  • Scalability: In a monolithic application, resources are allocated across the application. In a microservices-based design, developers can allocate resources only to the services that need them. This makes each service more scalable and improves the overall scalability of the application by ensuring faster responses to particular strains and cheaper costs by only using additional resources as necessary.

Disadvantages of microservices architecture

Most of the disadvantages of a microservices approach emerge from complexity that’s either too overwhelming for some companies to manage or so burdensome that the consequences of complexity outweigh the benefits of microservices altogether.

  • Increased maintenance costs: A consequence of splitting an application into isolated services is that each isolated service tends to require separate maintenance, troubleshooting, and testing work. Distributed systems are often harder to test, especially when service dependencies make it difficult to run a local environment altogether.
  • Organizational complexity and overhead: The agility and flexibility of microservices introduce organizational complexity and drive up overhead costs. Because developers are using different tech stacks, there’s more pressure on managers to set and maintain responsibilities and specifications. Over time, if complexity isn’t kept in check, development teams can end up less efficient than before, as shared standards, patterns, and knowledge is lost.
  • Coordination complexity: Ideally, microservices require little coordination, because each service is exposed via API. But in reality, separate services have to reliably work in conjunction to form an application, and for many companies, it becomes a struggle to maintain cross-service dependencies and manage API versioning issues. The application, despite its decentralization, can end up being brittle.

Read more: How to Reduce Maintenance Costs For Your Ecommerce Site

The emergence of blended commerce platforms

The lists of pros and cons for monolithic and microservices architecture often muddy the waters for retailers searching for the right solution for their business. Monoliths require less overhead, but they’re difficult to scale. Microservices architecture gives you more flexibility and development control, but they can be unwieldy to manage, and fully custom builds may create performance issues and failure cascades.

But above all else development teams loathe being locked into a single architecture—and developers are taking it upon themselves to research new technologies.

While it’s been widely accepted that developers are constantly searching for platforms that grow with them, research now shows this is far from anecdotal. According to the 2023 Stack Overflow Developer Survey, over 80% of respondents said they investigate new technology purchases on their own instead of relying on a list provided to them. Additionally, a report by IDC found that 38% are exploring possibilities or planning changes to their commerce architectures, while another 29% have already decided to change their commerce architectures.

Many commerce platforms specialize in full stack, modular, or headless commerce solutions. However, it’s clear that this one-size-fits-all approach no longer meets the needs of growing enterprises. In response, Shopify offers a suite of headless, composable, and full-platform commerce options that give you as much (or as little) flexibility as you need. This suite reduces unnecessary complexity and helps you go to market faster with a flexible stack that meets your business’s unique needs.

Shopify for enterprises gives brands a unique combination of connectivity, optionality, and innovation. Businesses get access to our high-performing commerce components, such as our checkout, cart, search, and internationalization, just to name a few. Commerce Components by Shopify also gives you the flexibility to integrate your existing services with Shopify’s modular components via an API layer, which creates a clear path to building unique customer experiences across all devices and touchpoints. All of this is backed by Shopify’s global infrastructure, ensuring you have fast and resilient storefronts that deliver best-in-class experiences to customers around the world.