While cloud adoption in general has been on the rise, the migration of business-critical legacy application workloads to the cloud has been relatively cautious. Apart from financial risk, the primary reason for this precaution is the inherent risk to business operations.

Customers who venture into application refactoring have broadly two options:

A) Big-Bang Refactoring

The traditional approach to convert legacy applications into micro-services is tedious & time-consuming. It involves a manual process to rewrite/recode the entire application in order to run it in the new cloud environment. Apart from being time-consuming, this big-bang rewrite of application poses a significant risk for the organization. Refactoring applications with millions of lines of code, written over decades, have a higher probability of exhibiting unknown side-effects. These unknowns are discovered much later in the big-bang refactoring approach which leads to lost time and cost.

“The only thing a Big Bang rewrite guarantees is a Big Bang!” – Martin Fowler

B) Phase-wise Refactoring

Executing application refactoring in a phase-wise manner eliminates the majority of the risks associated with big-bang refactoring. In this approach, the monolith legacy application is first broken down into underlying processes. Each process is then containerized separately. These processes can further be decomposed into micro-services over a period of time.

Application Refactoring RISK Chart

Key observations from the chart above

• Running legacy applications in their As-Is state entails security risks, due to outdated software stack and underlying platform vulnerabilities.
• Phase-wise refactoring reduces this risk by allowing the application to run on the latest platform in the cloud with minimal changes.
• The overall risk is lowered in a phase-wise approach as the process is automated. It also allows for unknowns to be discovered earlier in the process.

Conclusion

While digital transformation is driving organizations to rapidly undertake application modernization, they can hedge the inherent risks associated with application refactoring by following a phase-wise automated refactoring approach.

To read more about automated phase-wise refactoring, visit – Link.