Principal Frontend Engineer (ReactJS)

freeC's Client

Frontend Architecture & Development: Design, build, test, and refine modern frontend applications using the latest web technologies.

User-Centric Design: Work closely with product managers and designers to develop accessible, intuitive, and visually appealing interfaces that align with product goals.

Testing & Quality Assurance: Develop and maintain robust testing suites—including unit, integration, and end-to-end tests—using frameworks like Jest, React Testing Library, Cypress, and Playwright to ensure high product quality.

API Integration: Implement seamless and efficient communication between the frontend and backend services, ensuring responsive, real-time, and secure user experiences. This includes implementing reliable authentication and authorization mechanisms.

Performance Optimization: Continuously monitor, profile, and improve frontend performance to deliver a consistent and smooth user experience.

Code Quality: Write clean, maintainable, and thoroughly tested code that aligns with best practices and team standards.

Cross-Functional Collaboration:

• Collaborate with backend engineers to define and refine API contracts.
• Partner with QA engineers to ensure testability and high-quality deliverables.
• Work with data engineers to integrate data visualizations and analytics into the frontend.

Mentorship: Support and mentor junior frontend developers by sharing knowledge, conducting code reviews, and guiding their professional growth.

REQUIREMENTS

Technical Skills:

Essential:

• Minimum 8 years of experience in frontend web development.
• At least 3 years of hands-on experience with React.js and TypeScript.
• Strong understanding of:
• Component-based architecture and modern state management (e.g., Redux, Context API).
• Frontend performance optimization, especially when rendering complex and large-scale data visualizations, including best practices like lazy loading, bundle optimization, critical rendering path management, caching strategies, and profiling.
• Cross-browser compatibility and accessibility standards.
• Web security principles relevant to frontend development (e.g., XSS, CSRF, injection attacks).

Experience with:

• Modern build tools (e.g., Vite, Turbo, Webpack).
• Data visualization libraries (e.g., D3.js, Chart.js, Recharts).
• Integrating GraphQL or RESTful APIs, including secure authentication token management (e.g., JWT) and client-side authorization checks.
• CI/CD pipelines and Git-based workflows.
• Containerized development environments (e.g., Docker).
• Deploying and debugging frontend applications in production.
• Working in Agile development environments.

Preferred:

• Experience with server-side rendering (SSR) to boost performance, SEO, and deliver dynamic content.
• Advanced experience integrating data from multiple backend services in a microservices environment, including orchestration, data consistency, and optimization for high-performance BI applications.
• Ability to read or understand backend code (e.g., Golang, Python) to grasp data structures and services.
• Familiarity with cloud platforms (e.g., AWS) and frontend monitoring tools (e.g., Datadog, Sentry).
• Participation in Agile practices, design reviews, or sprint planning.

Communication:

• Strong teamwork and cross-functional collaboration skills.
• Experience mentoring and supporting other frontend developers.
• Strong sense of ownership, accountability, and a proactive problem-solving approach.
• Business-level proficiency in English (reading and writing required; speaking is a plus).

• Full salary during the probationary period
• Performance and salary review: twice/ a year in June and December
• 13th-month salary
• Monthly and biannual Recognition Awards
• An annual health check is provided
• Various insurances, including Social Security, Health, and Unemployment Insurance, are applied during the probation period. 
• Private health and accident insurance are also included, with additional benefits for family members at the Managing level.
• The hybrid working model allows for 3 days of remote work and 2 days in the office, with flexible start times.
• The facility is well-equipped, providing items such as a MacBook Pro and additional monitors. 
• Employees are entitled to 16-24 paid days off, with extra paternity leave days available.
• The company sponsors foreign language and international technology-related certifications.
• Annual company trips, quarterly team-building activities, and recreational clubs such as billiards and running.
• Employees have access to external and internal training courses, soft skills workshops, and technical seminars.