Application Re-Engineering is a key method in the digital transformation journey of an application. The existing application is re-engineered to make it scalable, flexible, and adaptive to new technological enhancement. This may involve complete uphauling of backend architecture, refactoring codes, introduction of third party cloud services and tools and much more. Application re-engineering modernize legacy systems and helps to build efficiency and optimize processes.
What Leads to Application Re-Engineering
Database migration
For legacy applications using on-prem database performance starts to lag as scalability is difficult to achieve. Sooner or later database migration becomes a necessity for business sustainability. This usually happens by migrating to a cloud database or third party large data warehouses which support scaling as required. Third-party databases may have different schema and methods of handling data than the traditional on prem database. This gives rise to the need of refactoring or re-engineering the legacy code to support smooth integration of databases and fast data exchange.
Cloud adoption
Legacy applications switch to a cloud based platform for improved productivity however they may have certain hardware and software dependencies, getting rid of dependencies and making them cloud-native requires re-engineering or refactoring. Even an existing cloud-native application may decide to switch their vendor for taking advantage of the cloud pricing model and optimize cost. This will in turn lead to some re-engineering to minimize resource usage, re-orient security protocols, and integrate new services and tools. Planning and executing the migration and re-engineering process carefully is essential to achieve the full benefits of the cloud.
DevOps integration
The integration of DevOps practices often exposes the limitations and inefficiencies in existing applications and processes. DevOps integration to cloud-native applications can improve the application performance by a million folds. The cultural shift associated with DevOps adoption warrants changes in how applications are designed, developed, and operated. To fully realize the benefits of DevOps, organizations may need to invest in re-engineering their applications to align with the principles and requirements of DevOps, making them more agile, efficient, and capable of delivering software at a faster pace.
Microservices adoption
Monolithic applications are slow, easily disrupts, and cumbersome to scale or upgrade which gives rise to microservices adoption. Microservices functions in a service based delivery model where each service works separately and isolated from each other. Converting a monolith to microservices involves breaking down the large codebase into smaller chunks of code working on a small service. This involves re-engineering to integrate and maintain a lot of features like defining service boundary, establishing communication channels between services, introducing automation, implementing fault tolerance mechanism, and much more.
Methods of Application Re-Engineering
Refactor
Refactoring is changing a part of the code to make it suitable for the upgraded environment. Refactoring is opted for when code restructuring would bring significant benefits in terms of performance, maintainability, and cost. The refactoring methods can be further classified into red green refactoring, refactoring by abstraction, composing method.
Replatform
Replatform involves migrating the codebase to a new platform with minimal changes introduced. Replatforming is attempted when the code is of relatively good quality and changing the environment will introduce significant improvements. Replatforming a on-prem application to a cloud platform like AWS or Microsoft Azure brings significant improvement in performance, speed of delivery, and cost reduction.
Rebuild
Rebuilding is typically attempted during the re-engineering of applications when the existing codebase or architecture is deemed too outdated, inefficient, or incompatible with the desired goals of the re-engineering process. Rebuilding involves creating a new application from scratch rather than making incremental changes to the existing codebase.
Steps to Application Re-Engineering
Assessment
The initial phase of the re-engineering process involves conducting a comprehensive inventory of all operational business applications, accompanied by detailed descriptions.
The primary objective of this stage is to gain insight into the current utilization of the software, identify the principal factors motivating the modernization efforts, and grasp the envisioned future state of the re-engineered application or technology stack.
Reverse engineering
The primary goal of this stage is to gain a precise understanding of the requirements and determine the optimal approach for the re-engineering process. By arming, the developers re-engineering the software, with this knowledge, it facilitates the assessment of the viability of planned changes to the application and the formulation of an effective path forward.
System transformation
The system transformation phase of application re-engineering involves strategic decisions regarding code refactoring, code replatforming, and, in some cases, code rebuilding to enhance efficiency and adapt to modern requirements. This phase is critical for shaping the application’s future.
Test
The test phase after application re-engineering is crucial for identifying and rectifying any issues, ensuring the reliability, security, and performance of the re-engineered application, and validating that it meets the desired objectives and specifications.This phase helps ensure a successful transition to the new system.
Deploy
After application re-engineering, deployment policies involve phased or incremental rollouts to minimize disruptions. Robust roll-back procedures are in place as a safety net. Extensive testing in a staging environment precedes full production deployment, ensuring a smooth transition to the re-engineered system.
Conclusion
Application re-engineering is a cost and resource saving process of overhauling an application by reusing the existing codebase. Application re-engineering is attempted when there is a chance of code reusability or complete overhauling of the application would be a very costly affair.
