Coming off the COVID pandemic, it's still urgent that companies meet consumer demand for reliable experiences, but in an uncertain economy this likely means keeping applications running with fewer resources. Legacy applications — those that aren't built on, and cannot easily interface with, modern infrastructure — are hindering digital transformation, can no longer meet enterprise needs, and can be financial and security liabilities.

The only way for companies to stay competitive is to modernize applications, yet there's no denying that bringing apps into the modern era can be challenging. Major obstacles to modernization include the high costs involved, disruption or downtime of critical functions, and the cost and time required for employee retraining.

Despite the perceived challenges, modernization efforts can yield big business benefits. They can result in long-term gains that offset short-term costs through stronger security, faster deployment, better performance, and more efficient resource usage. There are a few ways to modernize apps, and the specific approach you choose will heavily determine the benefits and trade-offs you experience.

Let's look at a few ways to modernize applications and consider what new obstacles and opportunities 2023 presents.

Application Rehosting

With this strategy, you move an application wholesale from legacy infrastructure (such as an on-premise mainframe) to more modern infrastructure, like the cloud. This is merely a stopgap measure, since the application itself is still not modernized. It can be useful for eliminating capital expenses, however.

Given that digital transformation is ongoing across every industry, this low-risk, low-reward strategy is likely insufficient for most use cases. If your legacy applications offer a poor user experience, low agility, excessive maintenance, or difficulty adapting to new use cases before rehosting, these shortcomings will persist after rehosting.

Rehosting in 2023 does offer the possibility of rehosting applications to edge compute solutions. For companies that need to see quick improvements at a low cost, an edge migration can help reduce latency by moving functions closer to end users or improving and preparing the applications to easily navigate throughout different types of infrastructures, including cloud.

Application Re-architecting and Rebuilding

These two approaches are substantially more drastic. Re-architecting involves changing substantial portions of an application to move to a new architecture, while rebuilding, as the name suggests, involves rebuilding an application entirely. Companies that undertake this task by themselves may find it costly and time-consuming, and that a skilled team is required for upkeep.

Whether re-architecting or rebuilding is the best fit for you depends on the current state of your legacy applications. If they are difficult to change, rebuilding may be ideal. Otherwise, re-architecting may be sufficient.

Application Replacement

If your current application cannot be feasibly re-architected, and rebuilding is prohibitively expensive, another strategy is to purchase a software-as-a-service (SaaS) product that accomplishes the same purpose as the outdated application without the costs of recreating it yourself. It can serve as a temporary solution until you have the resources to rebuild (or are able to finish the rebuild process), or it can serve as a permanent solution.

Take note: In 2023, many of the SaaS products you might employ run the risk of vendor lock-in and do not provide the flexibility enterprises need to customize features. Even if you later want to move away from them, the cost and effort required to shift to another provider could render this infeasible. Considering how valuable business agility is, this is a significant risk. Make sure to check that any platform you use adheres to open standards so that you can easily shift your application elsewhere as needed.

Application Refactoring

Application refactoring involves making small improvements to the code and architecture over time, though you (ideally) don't change app functionality at all during the process. For many companies that are aware their applications are outdated, this will likely be the best way forward, offering the least impact, a faster learning curve, and the best long-term results. Over time, you can make gradual changes without the need for any disruption. That includes the segregation of specific parts of the code into new microservices or functions, which are easier to maintain, update, and move to different infrastructure providers.

If your applications are severely outdated, such as those lacking standard internet protocols support — like HTTP — refactoring may not be enough. In that case, you'll need either to pay the price of rebuilding or replacing them, or consider implementing a new front-end component based on modern application architectures and incorporating a connector to your existing legacy application. This can substantially simplify the process while splitting it into multiple phases, and allows you to offer a strong user experience from the start. In turn, that will buy you more time to work on issues that don't impact users from day to day.

Getting Started

The reality is that most companies' daily duties prohibit the heavy burden required to stop everything and start the application development from scratch.

According to McKinsey, in 2023, companies in the top quartile of the Developer Velocity Index (DVI) outperformed others in the market by four to five times, proving that attracting and retaining developers is a critical need. Developers value the chance to work with modern tools and will likely be dissatisfied if they don't have access to them.

Relying on an edge platform — one that builds and maintains global infrastructure that its clients can use on an as-needed basis — is a great first step. By implementing a proxy architecture in front of your applications — such as the ones found on edge platforms — you can easily observe an application's behavior and potential starting points for making improvements. This approach also allows companies to run the entire refactoring process without needing to rehaul their infrastructures (such as migrating to the cloud or moving from one cloud to another).

While each of these modernization strategies has its own pros and cons, none of them can work unless you get buy-in from your organization's leaders. This means advocating for improvements that can impact the bottom line, explaining how new tools can substantially improve the developer experience, enabling faster and more straightforward development, and improving the customer experience.

Acknowledging the value of a modern architecture, shifting to the edge, and employing open standards can all go a long way toward ensuring a company has a financially sustainable application that developers can effectively use and evolve over time.