
Lead Software Engineer - ReactJS, Typescript
at J.P. Morgan
Posted 15 days ago
No clicks
- Compensation
- Not specified
- City
- Bengaluru
- Country
- India
Currency: Not specified
Lead a front-end team building modern React.js applications while maintaining and migrating legacy Ext JS modules. Define front-end architecture, coding standards, and a pragmatic migration path from Ext JS to React, balancing stability, performance, accessibility, and developer experience. Mentor engineers, conduct design and code reviews, and drive delivery in Agile sprints while collaborating with Product, Design and backend teams on REST/GraphQL and WebSocket integrations.
Location: Bengaluru, Karnataka, India
We have an opportunity to impact your career and provide an adventure where you can push the limits of what's possible.
As a Lead Software Engineer at JPMorgan Chase within the Commercial & Investment Bank's Margin & Collateral Technology team you’ll lead a team building modern React.js applications while maintaining and evolving existing Ext JS modules. A core part of the role will be planning and executing a pragmatic migration path from Ext JS to React—balancing stability, performance, accessibility, and developer experience.
Job responsibilities
- Define front-end architecture, coding standards, and best practices across React and Ext JS codebases.
- Drive the roadmap for migrating legacy Ext JS features to modern React implementations.
- Conduct design and code reviews; mentor engineers and elevate the team’s craft.
- Optimize performance (memoization, virtualization, bundle splitting, caching) and run audits with Lighthouse.
- Ensure robust test coverage with Jest and React Testing Library; enable e2e tests via Cypress or Playwright.
- Manage builds and theming via Sencha Cmd and SASS; improve performance and stability of legacy features.
- Implement bridging strategies (embedding React within Ext JS or vice versa) to enable incremental migration.
- Partner with Product and Design to deliver responsive, WCAG 2.1 AA-compliant experiences
- Work closely with backend teams on REST/GraphQL integration, WebSockets, and API contracts.
- Translate product goals into technical plans; break down work and drive predictable delivery in Agile sprints.
Required qualifications, capabilities, and skills
- Formal training or certification on software engineering concepts and 5+ years applied experience
- 10+ years of front-end development experience, with 3+ years in a tech lead or staff-level role.
- Deep expertise in React.js and TypeScript building large-scale, production-grade applications.
- Hands-on experience with Ext JS (6.x/7.x), Sencha Cmd, theming, and performance optimization.
- Proven track record migrating legacy front ends (preferably Ext JS) to React, including micro-frontend patterns.
- Strong proficiency with modern tooling: Webpack or Vite, Node.js, npm/yarn, Git, ESLint, Prettier.
- Solid understanding of accessibility, responsive design, and internationalization.
- Experience with automated testing across unit, integration, and e2e levels.
- Familiarity with RESTful APIs, GraphQL, and client-side performance profiling.
Preferred qualifications, capabilities, and skills
- Next.js (SSR/SSG), design system creation, and token-based theming.
- Data visualization (D3, Highcharts, Recharts).
- Monorepo tooling (Nx, Turborepo), micro frontends, module federation.
- Observability in the front end (logging, metrics, tracing) and bundle analysis.
- Experience in regulated or enterprise environments





