Application modernization is the process of taking existing legacy applications and modernizing their platform infrastructure, internal architecture, and/or features.
The benefits of application modernization can typically be summarized as improving the velocity of new feature delivery, exposing the functionality of existing applications to be consumed via API by other services, and re-platforming applications from on-premises to cloud for the purpose of application scale and performance as well as long-term data center and IT strategy.
Why modernize applications?
Legacy applications are also often monolithic applications. Monolithic applications have two characteristics that make it desirable to modernize them: they are difficult to update, and they are difficult and expensive to scale.
Monolithic apps are difficult to update for architectural reasons. Because all of an application’s components ship together, it is difficult and costly to add features given the overhead of complexity and integration challenges.
They are challenging and costly to scale for similar reasons. If even one component of an app is facing load and performance challenges, it can become necessary to scale up the entire app only to serve the most-demanding single component. This approach comes with considerable wasted compute.
By modernizing an application to more of a microservices architecture, components are smaller, loosely coupled, and can be deployed and scaled independently of one another. While bringing its own set of challenges, this approach is where much of the core value in modernization can be found.
Application modernization patterns
There are a handful of well-known approaches to application modernization that focus on a combination of the platform, the application’s architecture, and exposing an application’s functionality via API.
From monolith to microservices. The most common pattern of application modernization involves refactoring and breaking down a monolithic application into a collection of small, loosely coupled microservices.
In the above example of microservices architectures, a retail application was broken down from a single, n-tier application to a collection of microservices of all of the individual services within the app, each with their database and data model.
One approach in this space is known as the “strangler pattern.” Instead of breaking down the monolith all at once, the strangler pattern is about taking the application apart bit by bit, pulling out the easiest and most valuable parts first, and as this approach progresses, eventually there’s nothing left of the monolith.
Cloud migration. Often part of refactoring to microservices, replatforming or rehosting applications is almost always part of the modernization process. While it’s possible to simply lift-and-shift applications without doing much of a substantial rewrite, more often, the value is found in restructuring the application to better take advantage of cloud models, often leveraging containers and Kubernetes. (Learn more about cloud migration.)
Expose functionality via APIs
Finally, another approach to modernization can involve leaving an application in place but securely exposing its functions or data via APIs. This approach, based more heavily on integration than migration, enables new, cloud native applications to simply take advantage of the capabilities of existing systems and data.
Leave a Reply