
Swapnil Patil
Verified Expert in Engineering
Front-end Developer
Pune, Maharashtra, India
Toptal member since April 14, 2021
Swapnil has over ten years of experience working with Fortune 500 companies and infant-stage startups, including three years of remote work. He is experienced in building high-performing reusable components and responsive, accessible, scalable, and secure single-page web applications from scratch. He has worked on refactoring legacy codebase and improving application performance. Swapnil's been freelancing remotely on three continents, successfully managing multiple time zones.
Portfolio
Experience
- JavaScript - 8 years
- ECMAScript (ES6) - 6 years
- React - 5 years
- Webpack - 4 years
- ES7 - 4 years
- React Redux - 4 years
- Redux - 4 years
- TypeScript - 2 years
Preferred Environment
Slack, Visual Studio Code (VS Code), React, UI Development, JavaScript, Redux, ES7, ECMAScript (ES6)
The most amazing...
...thing I've developed was a payment integration with Western Union that is used to transfer money by millions of people around the world.
Work Experience
Lead Front-end Engineer
Cybersecurity Platform
- Led the design and implementation of scalable, performant, and accessible front-end applications within a complex cybersecurity platform ecosystem, reducing page load times by 35%.
- Designed and reprocessed event pools, increasing the throughput of real-time threat detection pipelines by 40% and reducing false-positive alerts by 25% through improved data correlation accuracy.
- Architected and optimized a natural language query builder using ANTLR, improving analyst query speed by 60% and reducing support tickets related to query syntax issues by 30%.
- Contributed to securing client-server communication by implementing JWT-based authentication flows in front-end applications.
- Integrated 40+ reusable React components and enhanced micro front-end architecture, boosting feature delivery by 50%, reducing build times by 25%, and enabling modular, parallel development across teams.
- Participated in containerizing front-end applications using Docker and automated deployments through CI/CD pipelines using GitHub Actions and Argo CD, ensuring consistent and reliable delivery to Kubernetes environments.
- Developed and architected a correlation rules builder for a cybersecurity alert application (SIEM), integrating MITRE ATT&CK mapping to enhance rule context and visibility.
- Spearheaded event reprocessing pipelines and optimized data import/export using batching and throttling, reducing latency by 60% and supporting real-time ingestion of millions of events per day.
- Followed OWASP best practices during front-end development by validating user inputs, sanitizing outputs, and preventing common vulnerabilities.
Senior UI Engineer
Analytics Platform
- Led the design and development of a micro front-end architecture for the Aera Platform, integrating 5+ core modules (Analytical Platform, Skill Developer, Process Builder, Workbench, and Decision Platform), and reducing deployment dependencies by 40%.
- Identified web-based user interactions and developed highly responsive UI components using React, contributing to a 20% improvement in user engagement across core modules.
- Developed modern, user-facing features using React and built a reusable component library, published as an internal npm package, reducing duplicate code across teams by 35%.
- Built internal tooling and mock API servers using Node.js and Express.js to simulate back-end responses during local UI development and component testing.
- Monitored and improved front-end performance by 15%, documented application changes, and worked on the updates.
- Used Express.js middleware for mocking authentication and routing logic, improving testability and reducing frontend-blocking issues during early development phases.
- Monitored and improved front-end performance by 15%, using Lighthouse audits and real-user monitoring tools to guide optimizations across critical user journeys.
- Utilized modern front-end build tools such as Webpack, Babel, and npm/yarn to improve code bundling, tree-shaking, and dependency management across micro frontends.
- Wrote 100+ unit test cases using React Testing Library and Jest, achieving 75%+ code coverage and reducing UI regression issues by 40%.
- Integrated both RESTful and GraphQL APIs into React applications, improving data handling efficiency and reducing overfetching on critical user interfaces.
Senior Software Engineer
Noissue
- Developed a community module for the project and reusable React components for the module.
- Tracked and fixed bugs using Jira as a reporting tool.
- Handled website loading time, managing image and asset loading time.
- Shared each functionality with stakeholders. Provided my suggestions on functionality and resolved feedback from stakeholders and peers.
Senior Software Engineer
Western Union
- Designed and coded application components in an agile environment, utilizing a test-driven development approach.
- Cooperated closely with project managers, product owners, and other functional team members to form a team effort in development.
- Took responsibility for estimating efforts to implement user stories, plan sprints, prioritize the sprint backlog, manage all the tasks, and report on progress.
- Identified potential obstacles and recommended alternative solutions to team members and a scrum master.
- Used Scrum for agile development and participated in team-led solutions, reviewing peers' code for quality and completeness.
- Collaborated closely with all other team members to take shared responsibility for the overall efforts that the team has committed to.
- Handled a team of five resources and contributed to production-iteration planning.
Senior Software Engineer
Globant
- Communicated with the client to gather requirements for sprint and created stories and subtasks with time estimation.
- Developed a generic Lego component using the AngularJS framework.
- Automated unit testing for the component unit testing.
- Contributed to unit test cases development, testing, debugging, and defect fixing.
- Produced estimations by evaluating instructions, specifications, and discussions with the onsite coordinator.
Consultant
Capgemini India
- Communicated with the client regarding the feasibility of a new finance project requirement in functional HTML. Worked on design changes, bug fixing, and adding functionality.
- Created and added Dojo functionality to web pages to create interactive forms.
- Developed accessibility for web pages as per Web Content Accessibility Guidelines (WCAG).
- Trained and guided team members on the current UI standards.
- Contributed to the responsive design of the websites, making them compatible with all small-screen devices.
- Handled cross-browser issues and provided fixes.
Software Engineer
Cybage
- Created different new and standalone pages using HTML, CSS, jQuery, and AngularJS.
- Converted the complete product from table structure to div structure in HTML.
- Made a non-responsive site responsive with the help of a UI designer. Worked on cross-browser compatibility issues.
- Conducted requirement and design analysis and coordinated with team members for test planning and scheduling.
- Contributed to the project's development phase, which included the user interface, admin functionality, and SEM creations.
- Tested the cross-browser compatibility and fixed the detected issues per business requirements.
Experience
Noissue (via Toptal)
https://noissue.co/It is an online tool where clients can create their designs for required packaging with quantities. Noissue also provides vast community pages to connect with environment-friendly people.
Detection Management
Key objectives:
• Develop a flexible correlation rules framework for detecting complex attack patterns (multi-event, sequence-based, and threshold rules).
• Provide a management console for creating, editing, testing, and deploying detection rules.
• Ensure real-time processing and high performance for threat detection at scale.
• Deliver a user-friendly UI for SOC teams to prioritize, investigate, and respond to alerts efficiently.
Core features:
• Rule authoring and testing: Analysts can write correlation rules using predefined templates or custom logic.
• Rule execution engine: Optimized to handle millions of events per day with low latency.
• Threat detection dashboard: Provides visibility into triggered rules, severity levels, and incident timelines.
• Integration: Connects with log sources, identity providers, and case management systems.
Analytics Platform
I created reusable plug-and-play React and analytics components using third-party tools such as AG Grid and FusionCharts. I have identified potential obstacles and recommended alternative solutions. I collaborated closely with the PO and PM for client requirement gathering and developing technical components.
EXL LifePro
Provenir Application
Western Union Mobile Application
https://www.westernunion.com/us/en/mobile-app.htmlEducation
Master's Degree in Computer Science
Pune University - Pune, Maharashtra, India
Bachelor's Degree in Computer Science
Pune University - Pune, Maharashtra, India
Skills
Libraries/APIs
React Redux, React, FusionCharts, Node.js, Lodash, PrimeNG, Reactstrap, React Query
Tools
GitHub, Git, Webpack 3, Jira, Webpack, Slack, Grunt, Gulp, Mongoose, Figma, Asana, Webpack 4
Languages
JavaScript, HTML, CSS, HTML5, ES7, ECMAScript (ES6), SCSS, TypeScript, JavaScript 6, CSS3, GraphQL, Less
Frameworks
Redux, Angular, AngularJS, Express.js, Bootstrap, Tailwind CSS, Vanilla JS, React-Bootstrap, MUI CSS, Flutter, Bootstrap 3, Next.js, Material UI
Paradigms
Management, UI Design, Responsive Web Design (RWD), Security Software Development, Responsive, Microfrontends
Platforms
MacOS, Visual Studio Code (VS Code), Contentful
Storage
JSON, MongoDB
Industry Expertise
Web Design
Other
Information Technology, User Interface (UI), Front-end, Front-end Development, Teamwork, Fintech, Web Development, UI Development, Software as a Service (SaaS), Algorithms, Axios, Communication, eCommerce, Fintech Consultant, Finance, Responsive UI, Data Visualization, Dashboards, Web Dashboards, AI Tools, Site Speed Optimization, Gatsby, Online Banking, APIs, Mobile App Development, Hybrid Apps, Responsive Design, Web UI, Web UX
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