Frontend Developer

Job Title: Sr. Front-End Engineer

Experience: 12+ Years
Location: Wilmington, DE
Work Model: 5 Days Onsite

Job Summary

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.

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.

Key Responsibilities

• 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.

Required Qualifications

• 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.

Preferred Qualifications

• 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.