Frontend Developer

Avanciers are seeking a highly experienced Sr. Front-End Engineer with expertise in React, TypeScript, and Java Spring to lead the development of high-performance web applications and scalable microservices. This role requires a strong front-end focus (60% React) with substantial backend development experience (40% Java/Spring), along with expertise in modern UI architecture, API integration, performance optimization, and engineering best practices., * Lead the architecture and development of complex, user-facing web applications using React, TypeScript, and modern JavaScript.

• Develop scalable microservices and API contracts using Java, Spring, GraphQL, and REST, following front-end-friendly design patterns.
• Establish front-end engineering standards for component architecture, state management, routing, coding conventions, and testing.
• Optimize application performance through bundle optimization, caching, rendering strategies, and Core Web Vitals improvements.
• Build advanced UI capabilities, including data visualization, real-time updates, complex forms, and workflow-driven experiences.
• Implement secure authentication flows and client-side security practices to protect against common web vulnerabilities.
• Lead testing strategies, mentor engineers, and drive code quality, accessibility, and production reliability.
• Leverage AI-assisted development tools such as Claude Code and GitHub Copilot for implementation, refactoring, testing, and debugging while ensuring code quality and security.

Candidates with experience at leading technology, financial technology, or Tier 1 companies such as Meta, Google, Amazon, Apple, Netflix, Goldman Sachs, and Morgan Stanley are preferred., * 12+ years of professional software engineering experience, with significant front-end development expertise and experience leading projects or mentoring engineers.

• Expert-level proficiency in React, including hooks, component composition, context, rendering behavior, and state management.
• Strong TypeScript and JavaScript skills, including generics, type design, and modern language fundamentals.
• Strong hands-on experience with Java, Spring, and microservices development.
• Experience designing and integrating GraphQL and REST APIs, including pagination, filtering, caching, and error handling.
• Expertise in front-end tooling, including Vite/Webpack, Babel/SWC, npm/pnpm/yarn, and build/release pipelines.
• Advanced testing experience with Jest/Vitest, React Testing Library, and Playwright/Cypress.
• Strong understanding of accessibility standards, including WCAG/ARIA, keyboard navigation, and screen-reader compatibility.
• Proven experience with front-end performance optimization, profiling, code splitting, SSR/CSR trade-offs, and caching strategies.
• Knowledge of web application security, including XSS/CSRF prevention, secure authentication/session handling, and dependency management.
• Experience with front-end observability, client-side logging, error reporting, and production debugging.
• Mandatory: Proficiency with AI-assisted engineering tools such as Claude Code or GitHub Copilot for coding, refactoring, test generation, and debugging., * Experience with Next.js, Remix, server-side rendering, and SEO optimization.
• Familiarity with design systems, Storybook, and design tokens.
• Experience with micro-frontends and module federation.
• Knowledge of data visualization tools, advanced tables/grids, D3, Canvas/WebGL, or animation libraries.
• Familiarity with OAuth2, OIDC, and enterprise single sign-on integrations.
• Experience modernizing legacy front-end applications and improving developer experience.

Top Skills: React, TypeScript, Java/Spring Boot, GraphQL/REST APIs, and AI-Assisted Engineering Tools.