As a part of the legacy modernization process, application refactoring is a crucial step for businesses aiming to stay competitive while the market is changing rapidly and user demands are constantly evolving. As a business owner, you might need help with managing technical debt and outdated applications that threaten your ability to adapt quickly. Furthermore, the lack of visibility and scalability in your current technology infrastructure can make sustainable innovation seem unrealistic.
This article explores strategies, challenges, and best practices for application refactoring, addressing these common pain points directly. Leveraging MobiDev’s 14 years of expertise in building and modernizing applications, we provide practical advice and real-world examples to guide you through a successful refactoring journey.
Understanding application refactoring
Application refactoring is a crucial aspect of app modernization process that involves restructuring the existing codebase without changing its external behavior. The primary goal of refactoring is to improve the internal structure of the application, making the code more efficient, maintainable, and scalable. By addressing issues like code complexity, duplication, or outdated practices, refactoring can enhance the overall performance and adaptability of the application.
As a software modernization technique, refactoring extends the application’s lifespan while improving performance, adding new functionalities, and strengthening security. Eventually, it can broaden the application’s reach by making it available across app stores on various platforms.
Developers often employ application refactoring to increase code modularity, making it easier to use, update, and maintain. These modular code segments can be reused directly or integrated into a cloud-native application that leverages microservices and APIs to combine multiple modules seamlessly.
This article can give you more insights on leveraging microservices for app modernization
Guide to Migration to MicroservicesWhen and why to refactor applications
Application refactoring often refers to legacy systems. Legacy code refers to outdated code that isn’t up to the standard of newer technologies or practices. It often includes source code written for operating systems or platforms that are no longer supported. Also, if the code is written by inexperienced developers, the system won’t take into account the future growth of the product.
In different cases, legacy code can include:
- code inherited from previous developers or older software versions
- code that is no longer maintained by its initial developers
- code written for unsupported operating systems, hardware, and file formats
- outdated software or code that is difficult to understand
App refactoring is most suitable in the following cases:
- Modernization and adding new features. If you want to upgrade the product, refactoring is a must-do in order to clean up code issues before they start to become critical for the application. Consequently, you save time and money for yourself or your development teams in the long run.
- When bugs and issues emerge. Messy code affects customer experience as no one will use the application if it doesn’t work right. Moreover, business processes can be at risk due to security breaches that may occur when bugs show up in systems.
So now that it’s clear that considering app refactoring can be a good idea, let’s get to the benefits it brings for businesses.
Benefits of application refactoring for business
Once you are familiar with the definition of refactoring, you’ll recognize its importance in your development workflow. Identifying the ideal time for refactoring depends on many factors. Here are some common scenarios where refactoring is beneficial.
1. Enhances system architecture
As you improve your code and gain a deeper understanding of your project, you’ll discover simpler and more efficient ways to write it. After a few months, you might find that the approach you initially took is no longer the best. By revisiting your code and adhering to best practices, you can enhance your application’s overall design. While poorly designed software might seem beneficial in the short term, it can lead to significant problems in the long run. Investing time in code improvement now can help you avoid future issues.
2. Refactoring makes code easier to understand
Adding new features to an application can be difficult, but maintaining outdated code in a legacy application is even more problematic. Iterative refactoring can reduce technical issues in legacy code, making it easier to understand and use. This process includes:
- removing unnecessary complexity or features
- deleting unnecessary code snippets
- breaking down larger classes and functions into smaller ones
3. Increased application efficiency & performance
One of the main reasons businesses choose refactoring is to increase efficiency. Tangled, voluminous code can waste developers’ time during bug fixes and updates. Refactoring streamlines the code, making systems more responsive. This results in faster completion of tasks, more satisfied users, and can increase revenue in the long run. Investing in refactoring now can save significant time and money later.
4. Refactoring speeds up code writing
Refactoring not only improves the structure of the code but also speeds up the coding process. For larger projects, refactoring might seem time-consuming initially, but it pays off by organizing your current code, making it easier to modify and recycle. This accelerates bug fixes and simplifies the code structure, enhancing the team’s ability to maintain high code quality.
5. Lowers technical debt
Application refactoring helps businesses save costs. The cost of software development increases as new features are added, often leading to technical debt. By refactoring, businesses can reduce the costs of dealing with technical debt and save time.
6. Easier product improvement
To stay competitive, it’s essential to design products that can be easily updated with new features. Refactoring reduces the risk of breaking the entire program while making these updates. This ensures that your products receive top-notch upgrades and popular additions, potentially boosting sales.
Exploring 7 application refactoring techniques
Let’s examine seven effective refactoring techniques that can significantly streamline and optimize your codebase for better outcomes.
1. Red-Green refactoring
Red-Green is one of the most well-known refactoring techniques in application development. This approach follows a “test-first” strategy, foundational for all forms of refactoring. Developers integrate refactoring into the test-driven development cycle, by following three specific steps:
- Red: start by writing a failing “red” test. This helps identify what needs to be developed
- Green: write just enough code to pass the “green” test
- Refactor: improve and enhance your code while ensuring the test remains green
Essentially, this technique consists of two parts: adding a new function to your system and refactoring the code that implements this function. Both tasks should not be done simultaneously during the workflow.
2. Refactoring by abstraction
This technique is used when a large amount of refactoring is needed, typically to reduce code redundancy. It involves creating abstract layers and reducing redundancy through class inheritance, hierarchy creation, and method extraction.
Examples of abstraction refactoring include:
- Pull-up method: moves code into a superclass to eliminate duplication
- Push-down method: moves code from a superclass down to subclasses
- Encapsulated field: uses code to access fields through getter and setter methods
- Generalize type: creates more general types to allow code sharing and replaces type-checking code with state or polymorphism
3. Composing methods
Composing methods focuses on breaking down large methods into smaller, more manageable ones. This makes the code easier to understand and maintain.
- Extract method: create a new method from a code fragment and replace the fragment with a call to the new method
- Inline method: replace method calls with the method’s content when the method is no longer needed
This technique reduces complexity and enhances code readability.
4. Simplifying methods
There are two techniques involved in this approach:
- Simplifying conditional expressions: this is simplifying logic to make the program easier to understand. Examples include consolidating conditional expressions, decomposing conditionals, and replacing conditionals with polymorphism.
- Simplifying method calls: this is making method calls simpler and easier to understand by modifying the interaction between classes and simplifying interfaces. Examples include adding, removing, or introducing new parameters, parameterizing methods, and preserving whole objects.
5. Moving features between objects
This technique involves creating new classes and moving functionality between old and new classes while concealing implementation details from public access.
You can choose this approach when:
- a class has too many responsibilities
- a class is unnecessary and does nothing substantial
Examples include moving a field, extracting a class, moving a method, inlining a class, and hiding delegates.
The good news is that you don’t need to be an expert in refactoring techniques to ensure your project’s success. At MobiDev, our experienced engineers will select the most appropriate refactoring methods tailored to address your specific business challenges. Our team will handle all the technical details, allowing you to focus on your core business objectives while we improve your application’s performance, maintainability, and scalability.
Application Refactoring Process
MobiDev’s refactoring process is a proven approach that has demonstrated its effectiveness over a decade of successful products delivery. Below we are sharing a detailed step-by-step guide to our application refactoring process.
Let’s take a look at each step closely.
Step 1. Assess the current state of the application
Review the existing source code thoroughly to understand its structure, dependencies, and functionality. Utilize tools for static code analysis to identify problematic areas. Determine parts of the code that are hard to maintain, have high technical debt, or show poor performance. At MobiDev, we ensure the Code Assessment stage is supported by thorough and transparent documentation. This documentation is designed to be clear and understandable, allowing clients to easily follow the assessment process and its findings. Moreover, the documentation is verifiable, meaning that all the conclusions and recommendations provided can be backed up with evidence and data.
Step 2. Set clear objectives for application refactoring
Establish specific, measurable objectives for the refactoring process. These could include improving performance, enhancing readability, reducing complexity, or increasing test coverage. Rank refactoring tasks based on their impact and urgency to ensure the most critical issues are addressed first.
Step 3. Create a refactoring roadmap
Outline a comprehensive roadmap detailing the refactoring tasks, their arrangement, and the expected outcomes. Ensure the plan aligns with the overall project timeline and resources. Allocate sufficient time for each refactoring task within the project schedule to avoid rushed and incomplete work. You don’t need to stop feature development to start refactoring. According to our experience, it is enough to devote 30% of development time to make good progress in refactoring.
Step 4. Set up a testing environment
Implement automated tests to validate the functionality of the application before, during, and after refactoring. Unit tests, integration tests, and end-to-end tests are essential to ensure that refactoring does not introduce new bugs. Execute all existing tests to establish a baseline for comparison post-refactoring.
Step 5. Refactor using the chosen refactoring approach
You might start with small, gradual changes to the codebase. Refactor one module, function, or class at a time to minimize risk and make debugging easier. After each change, run your automated tests to ensure that the code still works as expected.
Step 6. Prepare the documentation
Keep the project documentation up to date with the changes made during refactoring. This includes code comments, README files, and any other relevant documentation. Regularly update your team on the progress and changes made to ensure everyone is on the same page.
Step 7. Review and optimize
Conduct code reviews to validate the quality and correctness of the refactored code. Peer reviews help catch issues that automated tests might miss. Look for additional opportunities to improve the code. This could involve optimizing algorithms, reducing code duplication, or enhancing readability further.
Step 8. Deploy and monitor
Roll out the refactored code to production gradually. Monitor the application closely for any issues that might appear. Track performance metrics to ensure the refactoring has achieved its intended goals without introducing new problems.
By following these steps, you can systematically and effectively refactor your application, improving its maintainability, performance, and scalability.
Best practices for refactoring applications
To make refactoring projects succeed, consider using the following best practices:
1. Better assessment, better results
Before initiating refactoring, thoroughly review the source code to ensure a comprehensive understanding of the application’s components. Utilizing a sequence diagram can help visualize the steps involved in the code.
2. Time planning is a key
Refactoring can be time-consuming, so it’s crucial to plan the timeline carefully. Identify the steps needed to complete the project within a reasonable timeframe. Refactor code only when you are confident it can be made more efficient and maintainable to avoid additional technical debt.
3. Always test
Although refactoring doesn’t change the program’s functionality, testing is essential to ensure the new code doesn’t introduce bugs. Involve testers and QA in the refactoring process to avoid inadvertently affecting the product’s functionality.
4. Focus on the process, not perfection
Accept that you may never be 100% satisfied with the refactoring results. View the process as ongoing maintenance, requiring regular cleaning and organization of the code.
MobiDev success stories: real-world application refactoring examples
Refactoring is usually a starting point for any project that requires legacy app modernization services, and the quality of the work that is done while implementing this step will impact the future of the entire app development process. Here are several examples of how it looks in practice from MobiDev experience and what business outcomes it can help to achieve.
CASE STUDY 1: REFACTORING A HEALTHCARE APP TO PREPARE IT FOR ADDING NEW FEATURES
The primary objective of this healthcare application modernization project was to develop and implement new features. However, a technical audit conducted by MobiDev engineers revealed that the system’s low code quality and technical issues were hindering its correct operation. Faced with strict deadlines and budgets, adding new features to the existing system could have introduced new bugs. Therefore, we recommended starting with refactoring key modules to accelerate the development process and ensure the application’s stable operation.
How we delivered:
- Conducted code refactoring and bug fixing: Using ESLint, our engineers identified and fixed code issues. A prioritized task plan was created, focusing on refactoring key project modules. This effort resolved critical bugs, improved code readability, and standardized the code style, making it easier and faster to add new features and enhancing the system’s stability.
- Optimized database: The project utilized MongoDB, and our task was to organize the database more efficiently and enhance its performance. We removed unused values and fields and added validation to all forms on both the back end and front end, preventing the creation of incomplete entities and ensuring users filled in all necessary fields.
- Prepared the product for adding new features: The primary issue preventing new features was poorly structured and confusing source code, known as spaghetti code. We applied the Single Responsibility Principle to each component, which initially had business logic divided among the controller, services, and repository. We also deleted unused code and outdated dependencies, improving the project’s structure and reducing its vulnerability.
The low quality of the code can become a serious obstacle in the further development of the product because the system must be up-to-date in order to add new functionality. Refactoring and optimizing the code allowed us to reduce this risk and significantly improve the stability, maintainability, and security of the application. The client continues to work with MobiDev and we are currently working on some exciting new features.
Business outcomes:
- Increased operational efficiency: Refactoring critical modules and optimizing the database significantly enhanced the application’s stability and performance, resulting in faster processing times and more reliable operations.
- Reduced maintenance costs: Addressing low code quality and system inefficiencies reduced long-term maintenance burdens, lowering operational expenses and minimizing the need for frequent fixes.
- Improved scalability: Implementing the Single Responsibility Principle and removing outdated dependencies facilitated the seamless addition of new features, ensuring the application can grow with the business and adapt to future advancements.
- Enhanced security and compliance: Updating libraries and implementing robust validation and error handling improved the application’s security, ensuring compliance with industry standards and regulatory requirements.
CASE STUDY 2: REFACTORING AND REARCHITECTING A CRM APPLICATION WITHIN TIGHT DEADLINES
Our cooperation with the client began with a request to resolve issues with their existing CRM product and improve its performance. The application needed to be updated within a month. Given the short timeframe, it was impractical to refactor the entire system, so we opted for a selective and gradual improvement approach.
How we delivered:
- Updated the highly outdated framework version: The Codeigniter version of the framework was no longer supported, so our PHP developers suggested a gradual migration to a newer version. We prioritized and divided all functionality into modules, each isolated in a new project with up-to-date dependencies and environments.
- Improved code quality with refactoring: The poor quality of the code required extensive time to understand the logic of each method. Due to the project’s size, we couldn’t fix everything at once. Instead, we refactored only the functionality we were currently working on, meeting the deadline and saving the client money. Within six months, approximately 80% of the code was covered.
- Built a new scalable architecture: To provide application rearchitecting, we moved the database and file storage from the server to remote services (AWS RDS, AWS S3), which are more stable and secure. We then wrapped the architecture with Docker and isolated each service (NGINX, PHP, and Socket) into containers, enabling stable automatic code delivery (CI/CD) and optimizing server resources.
Initially, the project only had a month’s work to do. It was difficult to fit all the necessary improvements into such a limited period of time, and it was a really interesting challenge for us to choose what was the most critical.
As a result of a month’s work, the client decided to continue cooperation with our team, and it made it possible to improve the code according to the plan prepared earlier without stopping the delivery of new functionality.
Business outcomes:
- Improved customer experience: Addressing legacy code issues enhanced user experience and satisfaction, reducing support costs. Faster loading times, minimal downtime, and robust scalability contributed to a better user experience and opportunities for upselling or cross-selling additional features.
- Lower maintenance costs: Modernizing the application significantly reduced ongoing support expenses by eliminating outdated technologies and compatibility issues, streamlining maintenance efforts, and optimizing resources.
- Enhanced scalability: The new architecture allows for adding new functionality to meet growing user needs and adapt to evolving business goals.
By refactoring and modernizing these applications, MobiDev ensured that the clients could continue to develop and expand their software solutions efficiently, maintaining high standards of quality and performance.
Read the full case study:
MODERNIZING AND REFACTORING A LEGACY CRMQ&A Section
1. How to combine refactoring with developing new functionality?
Break down the refactoring assignment into as many smaller tasks as possible. Identify the core functionality required for all tasks and address it first. This approach helps to parallelize the tasks, making them independent and allowing for separate releases. This is a significant advantage because tasks can be released along with new features without needing to complete everything beforehand.
If new functionality is continuously being developed, perform refactoring tasks once the new functionality tasks are completed or when developers are blocked by other factors (such as waiting for design changes or back-end updates).
2. How much time does it take to refactor an application?
The time required depends on the number and type of components that need restructuring. However, when organized correctly, this process should not affect the development speed. Different software projects require different approaches, but effective planning and implementation ensure minimal impact on overall progress.
3. Does refactoring come with risks or downtime?
When done carefully and with proper testing, refactoring minimizes risks and downtime. Thorough testing of all changes before deployment helps mitigate potential issues. Modern refactoring tools and techniques also assist in automating and validating these changes.
4. How to prioritize which parts of the application should be refactored?
Prioritization should be based on factors such as spots with frequent bugs or maintenance issues, sections of code that are difficult to understand or modify, performance bottlenecks, or modules that will be expanded or integrated with new features. Focus on areas that provide the most significant business value and improvement in software quality.
5. What are the costs associated with refactoring, and how to calculate them?
Refactoring costs include developer time and resources required for making changes and testing them. However, these costs are often outweighed by the benefits, such as reduced maintenance costs, improved developer productivity, and increased customer satisfaction. Justification is based on long-term benefits and ROI rather than immediate cost savings.
6. How to choose trusted engineers for app refactoring?
Selecting reliable engineers for app refactoring involves evaluating their experience with similar projects, understanding their approach to refactoring, and ensuring they have a good understanding of modern refactoring tools and techniques. Look for a proven track record of successfully modernized applications and positive references from past clients or employers.
How MobiDev application refactoring services can help you succeed
Since 2009, MobiDev has been dedicated to developing, scaling, and modernizing software solutions. Our vast experience across numerous industries and projects of various complexity makes us a reliable team for your application refactoring projects.
MobiDev’s team of in-house consultants and engineers excel at auditing your software and current infrastructure. We develop detailed refactoring plans customized to meet your specific needs and implement them effectively, ensuring your operations face minimal disruption. Let us help you fully realize the potential of your legacy application and meet your business goals!
