Senior JavaScript Developer

Montash; Essen; Vor Ort; EUR 80.000 - 100.000; Vollzeit

Zusammenfassung

A leading company is seeking a freelance frontend developer for a customer-facing, product-focused role. Candidates will be responsible for end-to-end development of web applications, emphasizing API integration and creating scalable UI components. This role offers the opportunity to significantly impact product architecture and user experience.

Qualifikationen

• Proven experience leading end-to-end development of complex web applications.
• Strong understanding of API integration and frontend architecture.

Aufgaben

• Contribute to architectural decisions and hands-on development.
• Collaborate closely with backend engineers and product teams.
• Focus on performance, responsiveness, and user experience.

Kenntnisse

API integration

Frontend architecture

Responsive design

End-to-end development

Clean user experience

Jobbeschreibung

Contract Type : Freelance / B2B

Contract Length : 6 months (+ extensions)

Start Date : July 2025

Work Schedule : EU or UK candidates considered

Interview process : 2 Stage (Including live technical assessment)

This is a customer-facing, product-focused role where performance, responsiveness, and clean user experience are top priorities. You’ll contribute to both architectural decisions and hands-on development, collaborating closely with backend engineers and product teams.

Key Skills :

• Proven experience leading end-to-end development of complex web applications
• Strong understanding of API integration and frontend architecture

Bonus Skills :

• Experience working on customer-facing products (web and / or mobile)
• Skilled in integrating and managing API endpoints , including validation and error handling
• Ability to build scalable, reusable UI components and improve existing workflows
• Familiarity with cryptography principles (e.g., symmetric / asymmetric encryption)
• Knowledge of Web Workers and Service Workers

Tech Stack & Focus Areas :

• Frontend Development : Expertise in semantic HTML, CSS styling, and responsive design principles
• API Integration : Comfortable with request lifecycles, status code handling, and tools like AbortController
• Advanced Frontend Concepts : Practical experience with debouncing, memoization, error boundaries, unit testing, and mocking strategies