React Upgrade and Modernization Services
Don’t let your software silently decay and affect your business. Leverage our React upgrade and modernization services to innovate without major user disruption and at a reasonable cost. We will help you with React version migration, legacy code refactoring, and performance optimization to make your app easier to evolve and maintain.
When React Upgrade and Modernization Become Essential
The release of a new React version doesn’t necessarily mean you need to upgrade. Likewise, if your app relies on an older architecture, this factor alone doesn’t call for modernization. However, they become essential in the following scenarios:
- Accumulated security vulnerabilities are critical to your business and impossible to mitigate without an upgrade;
- Your application is built on a Create React App toolchain, which is no longer maintained, and key ecosystem libraries don’t support your current React version, delaying feature delivery and security fixes;
- App maintenance requires increasingly more effort because small changes often cause regressions that are difficult to fix;
- Large JavaScript bundles, unnecessary re-renders, and inefficient state management make your app interface feel sluggish, resulting in higher user churn;
- Your application stops passing Core Web Vitals, which lowers its search rankings and reduces new user acquisition.
For over 16 years, SysGears has accumulated extensive experience in modernizing legacy software used by SMEs and enterprises across multiple domains. Our team has launched more than 350 projects, most of which involve frontend development with React. Our ultimate aim is to build extensible and maintainable applications that serve businesses in the long term.
Benefits of Keeping Your React App Up-to-Date
Faster Performance
Make your app frontend run faster and improve responsiveness through targeted architecture modernization. If your app is built with React 16 or other older versions, consider upgrading. This will give your development team access to newer capabilities for performance optimization.
Improved Security
Remediate React vulnerabilities before they affect your app’s operation. New versions include the latest security patches for newly discovered risks, so your app keeps running reliably.
Cost-Effective Maintenance
Keep React app technical debt under control and optimize maintenance effort in the long run. Legacy React application modernization helps you reduce workarounds and architectural inefficiencies, making future changes easier to implement.
Access to New React Features
Leverage new React capabilities to accelerate the development and optimize engineering effort based on the latest React best practices. New features may simplify both implementation and maintenance, while supporting more optimal app operation.
Our React Upgrade Services: What’s Included
React Code Audit & Refactoring
If your React application has accumulated technical debt that makes it increasingly fragile, our React developers can help you revitalize it. We will inspect your codebase, identify risk areas, prioritize them by severity, and refactor your application to make it easier to maintain and extend as your business needs evolve.
Gradual Version Upgrade
SysGears can upgrade your app from React 16/17 to the latest versions or migrate projects from CRA to Next.js, using an incremental approach. This means your application continues to function without interruption while we transition the codebase in phases, handling compatibility issues and breaking changes.
If your web app loads slowly, our team can find the root cause and optimize its performance. We develop a tailored optimization strategy for every project, with common practices including reducing unnecessary re-renders, splitting large JavaScript bundles, optimizing state management, and removing unused dependencies.
Security Upgrade
SysGears mitigates outdated React version security risks by patching vulnerable dependencies, replacing unmaintained packages, and removing deprecated code paths. If broader security hardening is required, we can also review unsafe HTML rendering, client-side token storage, exposed credentials, and API interaction patterns.
Upgraded App Testing
Modernize the React codebase confidently while running regression tests all throughout the process. Our QA team will verify that your app continues to function as expected after dependency updates, breaking changes, architectural modifications, and new feature implementations. We combine manual and automated testing to optimize QA time and reduce the risks of hidden defects reaching production.
App Maintenance After the Upgrade
Our team can provide ongoing maintenance for your upgraded React application to ensure it remains viable and competitive. As part of our service, we can implement targeted fixes, launch new features, and optimize performance, while adjusting the size of our team to each project stage.
Other React Modernization Services We Offer
Application Re-Engineering
In addition to upgrading framework and libraries, our team can rearchitect your application to accelerate feature implementation and simplify further maintenance.
New Feature Implementation
As part of React app modernization services, our engineers can implement new features or enhance existing ones, so your application remains relevant as your user requirements change and your business evolves.
UI Enhancement
SysGears modernizes outdated app interfaces to improve visual consistency, responsiveness, and usability across target devices. We can replace legacy styling with Tailwind CSS and create reusable UI components, enhancing user interactions without compromising performance.
CI/CD Orchestration
We can implement production-ready CI/CD pipelines in your React project, automating builds, tests, and the deployment workflows to accelerate delivery and catch and fix issues early.
Why Hire SysGears For Your React Upgrade and Modernization Project
Senior React Engineering Expertise
Founded in 2010, SysGears has helped over 350 businesses worldwide achieve their goals through high-quality software development, including React implementation and modernization. Our internal engineering culture is built around continuous learning, knowledge sharing, retrospectives, and participation in open-source initiatives. By hiring specialists from SysGears, you gain access to up-to-date skill sets, rigorous quality standards, disciplined development practices, and openness to feedback.
Focus on Your Business
We measure every technical decision against its prospective value for your business. To see the full picture, our engineers carefully study your needs, establish consistent feedback loops, and modernize your React application incrementally. This way, we can track progress, assess the impact of each stage, and adjust the upgrade plan as needed.
Responsible Use of AI Tools
Our React developers use modern AI tools to increase productivity, while architecture, security, and overall strategy remain in human hands. This enables us to accelerate the modernization lifecycles without compromising quality.
Flexible Collaboration Models
SysGears offers three engagement opportunities that can be further adjusted to your business needs and budget. We can allocate a senior React developer for code audit, planning, and tech leadership. A dedicated modernization team can handle both implementation and business alignment. Alternatively, you can fully outsource your app development to SysGears to handle modernization, expansion, and ongoing maintenance.
Our React Expertise in Client Stories
React-Based Certification Management System
The Australian construction company hired SysGears to develop a document management platform that enables employees and managers to track active certifications, request certification renewals, and select appropriate candidates for each project. In particular, our React developers implemented a convenient certification status tracker and a leaderboard providing visibility into a team’s suitability for a particular job. Since the client’s company uses the Microsoft ecosystem, our team created a single sign-on option, enabling users to access the system with their Microsoft account. Besides implementing the solution, our engineers deployed it to SharePoint, enabling the client to manage all their digital tools through a single platform.
Animal Blood Bank BPA App Built with React
The SysGears team developed a custom web application to automate the essential business workflows for the North American Veterinary Blood Bank, including appointment scheduling, pet profile creation, donor eligibility checks, and application processing. Special attention was dedicated to product security, as it was vital to keep sensitive client details private. We also laid the foundation for the multi-language support required to expand the service in the future.
React SPA For Crop Growth Cycle Management
SysGears developed a crop growth cycle management application to enable smarter crop planning, reduce waste, and improve farm management during seasonal peaks. The solution provides recommendations on soil preparation, crop planting, cultivation, and harvesting, enabling farmers to choose plants suitable for their landscape and maximize yields. Users can track growth in real time through an interactive timeline and invite colleagues and partners to join the process by assigning tasks, providing access to the necessary data, and sending notifications. Due to scalable architecture and lightweight configuration, the application is easy to maintain and extend to enter new markets.
What Our Clients Say
5.0
“Their knowledge of the technology was the most impressive. They were able to offer suggestions and implementations that we were not aware of due to their experience.”
Jennifer Harding
Director of Interoperability & Integration, Crisis Logic
5.0
“Their exceptional creativity and inspirational ideas consistently deliver remarkable results, even in situations where our requirements may not be clearly defined. They have an innate ability to offer a plethora of options to choose from. Furthermore, we highly value their conscientious approach towards the business aspect of our collaboration. Their dedication to not only completing specific tasks but also achieving our overall objectives is truly appreciated.”
Executive
MotionElements
5.0
“They went above and beyond to understand the vision, and foresaw implementation complexities well in advance.”
Joseph Corey
Founder & CEO, Subspace
Breathe new life into your React application with SysGears.
Our React Technology Stack
Core Frontend Technologies
JavaScript
TypeScript
React
NestJS
Libraries
React Router
React Hook Form
Axios
Zod
Yup
Day.js
Date-fns
Lodash-es
State Management
Redux
MobX
Apollo GraphQL client
Testing Tools
Jest
React Testing Library
Cypress
Enzyme
Mocha
Chai
Puppeteer
UI frameworks
Material UI
Tailwind CSS
Ant Design
Build & Development Tools
webpack
Vite
Turbopack
Babel
SWC
npm
pnpm
Yarn
Git
Docker
Performance & Monitoring
Lighthouse
Sentry
Datadog
New Relic
LogRocket
Fullstory
Our Upgrade and Modernization Process
Discussing Your Needs
First, we hold a call to learn more about your React app modernization needs and the business goals behind this initiative. You also get more information about our service offering, React expertise, and current pricing policies. Once aligned, we sign an NDA and a Service Agreement, assign specialists with the relevant experience, and start our work.
Studying the Current Setup
Our engineers begin with a codebase audit to identify outdated libraries, performance bottlenecks, and security gaps. When broader modernization is required, we look for code inefficiencies, architectural flaws, and violations of React best practices. We also carefully document data sources, APIs, and integrations. Careful inspection of the system’s components helps us prioritize upgrade and modernization phases.
Developing an Actionable Roadmap
Once key issues are identified, our team creates a detailed upgrade and modernization roadmap around them. It includes goals, phased delivery milestones, success metrics, resource estimates, and risk mitigation strategies. This step is vital to prevent surprises down the line.
Gradual Implementation
For a version upgrade, we incrementally update outdated dependencies, replace deprecated features with newer alternatives, and migrate your app to a newer React version, using intermediary versions as a bridge (e.g., moving from React 16 to React 18.3 before React 19).
In case of broader modernization, our engineers gradually refactor legacy modules, revamp state management, improve the architecture, remediate security vulnerabilities in the code, and enhance the UI and accessibility as needed.
Before the release, we run manual and automated tests to ensure the application runs correctly after changes. As a standard step, we prepare backups and rollback plans to reduce production risks.
Deployment and Support
We deploy your updated application to the live environment. Our engineers can further support the stable operation of your application through bug fixes, security updates, and new feature implementation.
Other Services We Offer
FAQ
Do I need to upgrade my React app if it’s still functioning?
Running an application on an older React version doesn’t call for an immediate upgrade. However, it becomes necessary once the current version exposes the app to uncontrolled security risks, prevents necessary dependency and framework updates, and causes compatibility issues with browsers and devices. All this may increase development and maintenance effort, limit the engineers’ abilities to introduce new features and fix bugs, and lead to decreased user adoption and retention.
If you deal with technical debt, inefficient architecture, and poorly implemented code, a version upgrade alone won’t solve the problem. These issues also require broader modernization. SysGears can handle both. We can conduct a gradual upgrade and improve your app’s maintainability, so it delivers long-term value.
What does React application modernization involve?
The scope of every modernization project may vary, depending on the goals set. It typically begins with a code audit, which includes a review of dependencies and third-party packages, a code maintainability and extensibility assessment, and the identification of security risks. Based on the findings, we evaluate modernization risks and edge cases, map out mitigation scenarios, and develop an optimal modernization plan, enabling phased implementation of changes. The modernization itself may also include code refactoring, architecture re-engineering, and performance optimization.
How do you upgrade a React 16 or 17 application to React 18 or 19 without breaking existing functionality?
We perform the upgrade incrementally, first updating compatible dependencies and then resolving deprecations and compatibility issues. When moving to React 19, we use React 18.3 as an intermediary version because it introduces warnings for changes that must be addressed before the React 19 upgrade. Migration work is performed in a separate Git branch and validated in a staging environment. We cover critical workflows with unit and integration tests, run regression testing throughout the process, and use controlled deployment and rollback procedures to reduce production risk.
Who performs the React codebase audit before the upgrade begins?
Before deciding on any changes, the engineers responsible for an upgrade will carefully audit your current codebase. This will help them more precisely identify problem areas, determine risks, and take them into account during upgrade planning.
What’s the difference between React modernization and a full application rewrite?
React modernization involves an incremental upgrade of dependencies, components, and architectural patterns, while the architectural foundation remains intact. In case of a full rewrite, the application is rebuilt from scratch, using a different architecture (e.g., microservices instead of a monolith) and technology stack (e.g., Angular to React migration).
A full rewrite is relatively rare, with partial rewrites being more common. It may be justified when the current architecture can no longer support new business requirements, and staffing becomes problematic due to an outdated technology stack.
How much does React application modernization typically cost?
The overall cost of a React modernization and upgrade project depends on its scope, complexity, the number of specialists involved, and their qualifications. For instance, a targeted feature update involving one engineer will generally cost less than a comprehensive modernization initiative with a full code audit, refactoring, dependency remediation, and security upgrades, conducted by a dedicated team.
Before estimating the costs, we need to get a detailed understanding of your needs. Contact us using the form below, an on-page chat, WhatsApp, or email info@sysgears.com. You can also book a call directly in our calendar.
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