Software Engineer III - Front-End Developer - ReactJS

JPMC Candidate Experience page
Ciudad Autonoma Buenos Aires, AR

About the role
We’re seeking a 602 Software Engineer to build and evolve modern web applications using React and Redux, with a primary focus on GraphQL for data access. You’ll collaborate with product, design, and platform teams to deliver secure, performant, and accessible user experiences at scale. Experience with micro-frontend (MFE) architectures is a plus.

What you’ll do

  • Build, test, and maintain responsive React applications using modern patterns (hooks, functional components, context where appropriate).
  • Implement predictable state management with Redux/Redux Toolkit, including middleware, selectors, and efficient store design; integrate cleanly with GraphQL client caches.
  • Integrate with GraphQL services using Apollo Client or urql: define queries, mutations, and subscriptions; manage normalized caching, pagination (cursor/relay style), error handling, retries, and optimistic updates.
  • Partner with backend teams on schema and API contracts (SDL), versioning, and performance patterns (query batching, persisted queries, avoiding n+1 issues).
    Partner with design to implement accessible (WCAG-compliant) and consistent UI aligned to a design system.
  • Write high-quality, well-tested code (Jest, React Testing Library); automate via CI/CD and follow trunk-based development or GitFlow as applicable.
  • Profile and optimize performance (bundle size, code splitting, memoization, virtualization, lazy loading) and GraphQL network usage (field-level policies, cache keys).
  • Participate in architecture/design reviews, code reviews, and contribute to shared libraries and component systems.
    Document components and patterns for reusability; mentor peers and contribute to engineering best practices.
  • Leverage AI-assisted development tools and prompt engineering techniques to accelerate coding workflows, generate boilerplate, write tests, refactor code, and improve documentation quality.
     

Must-have qualifications

  • Professional experience building production-grade React applications (typically 5+ years or equivalent depth).
  • Strong JavaScript and TypeScript fundamentals; ESNext, modules, and typing best practices.
    Deep experience with Redux/Redux Toolkit and app-level state architecture; familiarity with coordinating Redux state and GraphQL client caches.
  • Hands-on experience integrating GraphQL in production front-ends (Apollo Client or urql): queries, mutations, subscriptions, fragments, cache normalization and policies, pagination strategies, error boundaries, and GraphQL Code Generator.
  • Testing expertise across unit, integration, and component tests; familiarity with mocking GraphQL operations and contract testing.
  • Solid grasp of web fundamentals: semantic HTML, modern CSS (CSS-in-JS, Modules, or utility-first), responsive design.
  • Front-end build tooling (Webpack/Vite), package managers, and linting/formatting (ESLint, Prettier).
  • Understanding of auth flows (OAuth/OIDC, JWT), secure storage patterns, and front-end security basics (CSP, CORS, security headers).
  • Version control with Git and collaborative development in Agile environments.
  • Ability to effectively use AI coding assistants (e.g., GitHub Copilot, LLM Suite) and craft clear, context-rich prompts to improve productivity, code quality, and problem-solving efficiency.

Nice to have

  • Micro-frontend architectures (Webpack Module Federation, single-spa, import maps); experience with shared runtime and dependency governance.
  • Monorepo tooling (Nx, Turborepo) and shared UI libraries/design systems (Storybook).
    Node.js for front-end build tooling or BFFs; familiarity with GraphQL gateways and schema stitching/federation concepts.
  • Observability for front-end (metrics, logging, tracing, error monitoring) and feature flagging/experimentation.
  • Advanced accessibility expertise (ARIA patterns, keyboard navigation, screen reader support).
  • Cloud and CDN basics; understanding of edge caching and performance optimization for APIs and assets.
     

How we work

  • Customer-centric, iterative delivery with clear acceptance criteria and measurable outcomes.
  • Code reviews, pair/mob programming as needed, and continuous improvement through retrospectives.
  • Emphasis on reliability and resilience: meaningful monitoring, alerting, and on-call participation where applicable.
     
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