Sr Front-End Engineer

Avanciers Inc.; Wilmington (DE); On-site; USD 180,000 - 240,000; Full time

Job summary

Avanciers Inc. is seeking an accomplished Senior Front-end Engineer to lead the design and development of modern web experiences using React, with backend work in Java Spring.

You will own front-end architecture, drive performance improvements, and establish coding standards across teams. This role requires 12+ years of experience, fluency with GraphQL/REST, and a track record of delivering scalable UI and microservices.

Qualifications

• 12+ years of professional software engineering experience with strong frontend focus and leadership.
• Expert-level React proficiency (hooks, composition, context, rendering behavior).
• Strong Java and Spring skills to build microservices and API contracts (GraphQL/REST).
• Deep experience with modern frontend tooling (Vite/Webpack, Babel/SWC, npm/pnpm/yarn).
• Advanced testing practices (Jest/Vitest, RTL, Playwright/Cypress).
• Accessibility mastery (WCAG/ARIA, keyboard navigation, screen readers).
• Performance engineering (Core Web Vitals, bundling, caching, SSR/CSR).
• API integration with GraphQL and REST (schema-driven, errors, caching).
• Security awareness (XSS/CSRF, secure auth patterns, OIDC a plus).
• Observability for frontend (logging, metrics, debugging).
• Must: Proficiency using AI-assisted tools (Claude Code, GitHub Copilot).

Responsibilities

• Lead development of complex, user-facing web apps using React and own frontend architecture.
• Develop microservices/API contracts with GraphQL/REST using Java and Spring.
• Establish and evolve frontend standards incl. components, state, routing, testing.
• Drive performance and quality: Core Web Vitals, bundle optimization, caching, observability.
• Implement advanced UI features like rich visuals, real-time updates, offline patterns.
• Ensure secure client-side patterns and secure storage, auth flows, and vulnerability protections.

Skills

React

Java

Spring

GraphQL

REST

Vite/Webpack

Testing

Jest

Accessibility

Performance

Security

AI tools

Next.js

Remix

Design system

Storybook

Micro-frontend

Module federation

OIDC

Tools

Vite/Webpack

npm/pnpm/yarn

Job description

Please look profile from FAANG / High Tech & Fin Tech Companies.

Summary

Lead the design and development of modern, high-performance web experiences using React and the broader front-end ecosystem. This role is front-end (React) 60% and backend (Java Spring) 40% focused skills to deliver cutting-edge UI & Microservices capabilities and set engineering standards.

Job responsibilities

• Lead development of complex, user-facing web applications using React, owning the front-end architecture and delivery approach.
• Develop microservices / API contracts (GraphQL/REST) using Java and Spring technologies and front-end friendly design patterns (pagination, filtering, error models).
• Establish and evolve front-end standards: component architecture, state management, routing, code conventions, and testing practices.
• Drive performance and quality: Core Web Vitals, bundle optimization, rendering strategies, caching, and runtime observability.
• Implement advanced UI capabilities such as rich data visualization, real-time updates, offline-friendly patterns, and robust form/workflow experiences.
• Ensure secure client-side patterns: safe auth flows, token handling guidance, secure storage, and protection against common web vulnerabilities.

Required qualifications, capabilities, and skills

• 12+ years professional software engineering experience with significant depth in front-end web development; experience leading projects and mentoring engineers.
• Expert-level React proficiency (hooks, component composition, context, rendering behavior, concurrency-related patterns where applicable).
• Strong Java and Java Spring skills to develop microservices / API contracts (GraphQL/REST) using Java and Spring technologies and front-end friendly design patterns (pagination, filtering, error models).
• Deep experience with modern front-end tooling: Vite/Webpack, Babel/SWC, npm/pnpm/yarn, monorepos (optional), and build/release pipelines.
• Advanced testing practices: Jest/Vitest, React Testing Library, Playwright/Cypress for E2E; test strategy ownership.
• Accessibility expertise: WCAG/ARIA, keyboard navigation, screen-reader considerations, and automated + manual a11y testing.
• Performance engineering: profiling, bundle splitting, SSR/CSR trade-offs, caching strategies, and Core Web Vitals optimization.
• API integration expertise with GraphQL and REST (schema-driven development, error handling, pagination, caching, and client state strategies).
• Security awareness for web apps: XSS/CSRF prevention, dependency hygiene, secure auth/session patterns (OIDC awareness a plus).
• Observability for the front end: client-side logging/metrics, error reporting, and debugging production issues.
• MUST: Proficiency using AI-assisted engineering tools (e.g., Claude Code, GitHub Copilot) to accelerate implementation, refactoring, test creation, and debugging—while validating correctness and adhering to secure handling practices.

Preferred qualifications

• Experience with SSR/meta frameworks: Next.js / Remix and SEO considerations.
• Experience leveraging a design system (Storybook, tokens).
• Experience with micro-frontend patterns and module federation (where relevant).
• Experience with visualization and rich UI: D3, Canvas/WebGL, advanced tables/grids, animation libraries.
• Familiarity with authentication integrations (OIDC/OAuth2) and enterprise SSO constraints.
• Proven track record modernizing legacy front ends and improving developer experience (DX).