Senior Front-end Developer

Coolblue; Rotterdam; Hybrid; EUR 90,000 - 120,000; Full time

Benefits offered by this job

Monthly drinks

Snacks on site

Company parties

Hybrid work arrangement

Desk chair & home office setup

Travel allowance

Retirement plan

25 leave days

Office near Rotterdam

Coolblue University courses

Product discount

Job summary

Coolblue seeks an experienced Senior Front-End Developer to lead UI implementation using React/Next.js and contribute to full‑stack work in TypeScript and C#. You will mentor teammates, influence architecture, and ensure excellent user experiences.

You will collaborate with UX designers, participate in CI/CD, and help shape best practices in a dynamic, international team. This role blends strong front-end focus with practical back-end collaboration.

Qualifications

• 5+ years of experience as a Front-end React/Next.js Developer.
• Strong experience with TypeScript, React.js, Next.js.
• Proficient in modern JavaScript, HTML and CSS/SCSS.
• Experience mentoring teams and making technical decisions.
• Familiar with Scrum/Agile software processes.
• Fluent in English.
• Residence in The Netherlands.

Responsibilities

• Lead development of performant, user-friendly UI components using React.js and Next.js.
• Collaborate with UX Designers to deliver high-quality user experiences.
• Contribute to back-end logic when needed (Node.js or C# .NET).
• Make architectural and tooling decisions and ensure maintainability and performance.
• Mentor junior and medior developers and share knowledge.
• Participate in CI/CD and testing to uphold software quality.

Skills

React/Next.js

TypeScript

JavaScript (ES2017+)

HTML/CSS/SCSS

Mentoring

Agile/Scrum

English

Leadership

Education

BSc/MSc in Computer Science or related field

Tools

Node.js

C# (.NET)

Job description

As a Front-End React/Next.js Developer, you will help improve the user experience of our web applications at Coolblue, while being comfortable working across the full stack when needed. This role is primarily front-end focused, with hands-on full-stack expectations including back-end development in TypeScript and C#.

What does a Senior Front-end Developer at Coolblue do?

As a Senior Front-End React/Next.js Developer, you will take the lead in developing user interface components and implementing them using modern front-end technologies, including React.js and Next.js. Your primary responsibility remains the front end, while bringing a strong full-stack mindset to architectural and technical decisions. You will collaborate with UX Designers to create solutions that deliver high-quality user experiences and present them to the team. You will be involved in critical decision-making around architecture, processes, and tools, and be responsible for ensuring the overall performance and maintainability of the solutions. You will mentor junior and medior developers, provide guidance, and share your knowledge with the team. Would you also like to become a Senior Front-End Developer at Coolblue? Read below if the job suits you.

You Enjoy Doing This

• Leading the development and implementation of performant, user-friendly applications using React.js and Next.js.
• Reviewing and improving application requirements, interface designs, and web-based user interactions.
• Contributing to back-end logic such as APIs and server-side functionality using technologies like Node.js or C# when needed.
• Making critical technical decisions regarding architecture, tools, and processes.
• Collaborating with team members across diverse backgrounds and nationalities.
• Working with GitHub and writing automated tests to ensure software quality.
• Leading in a fast-paced Continuous Integration & Deployment environment.
• Coaching and mentoring junior and medior developers to elevate team skills.

You recognize yourself in the following

• You have 5+ years of experience as a Front-End React/Next.js Developer.
• You have a BSc or MSc in Computer Science or a comparable field.
• You have advanced experience with TypeScript and React.js/Next.js concepts.
• You have extensive experience with modern JavaScript (ES2017+), HTML, and CSS/SCSS.
• You are highly proficient with React.js and Next.js.
• You have experience with a Back-End runtime environment such as Node.js or C# (.NET) and understand how back-end choices impact front-end architecture.
• You have experience leading and mentoring teams and making technical decisions.
• Working with Scrum/Agile is second nature to you.
• You are fluent in English.
• You live in The Netherlands.

This is what you’re looking for in a job

• Money.
• Working together in an international environment with colleagues from the Netherlands, Belgium, Spain, Brazil, Mexico, Italy, and many more.
• An extraordinarily good work environment. Where we interact as friends and you can just be yourself.
• Monthly drinks, freshly prepared snacks, legendary Coolblue parties and the best team activities.
• A fine balance between working at the office and working from home. Of course, we’ll help you create the best home-office possible. Including desk chair, laptop, and blue garlands.
• Plenty of room for your own ideas, initiatives and choices. You do your work your way.
• Travel allowance, a retirement plan and an allowance when you work from home.
• 25 leave days. As long as you promise to come back.
• A picture-perfect office at a great location. You could crawl to work from Rotterdam Central Station. We recommend just walking for 2 minutes, though.
• With over 100 training courses in our own Coolblue University, you become a little better every day.
• A discount on all our products.