Back End Developer

Ever built something millions of people rely on daily? Here’s your chance.

Every second, thousands of users log in to one of Europe’s biggest e-commerce platforms.

Your job? Ensure that happens securely, seamlessly, and at scale.

As a Senior Java/Kotlin Developer, you’ll develop robust authentication systems, including login services, identity services, and OpenID.

You’ll work on highly reliable APIs and implement OAuth2 at a framework level, not just as a user.

Your Responsibilities

• Develop and maintain secure login and identity services
• Implement OAuth2/OpenID with deep framework understanding
• Build and optimize high-performance APIs
• Ensure scalability, security, and reliability

Your expertise

Hard Skills

• Strong Java & Kotlin development experience (true senior level)
• Deep expertise in OAuth2/OpenID, including framework-level knowledge
• Proven experience building and optimizing APIs in high-load environments
• Familiarity with JSP or React for better frontend collaboration (nice to have)

Soft Skills

• Proactive problem solver who takes ownership of complex challenges
• Strong communicator who can explain technical decisions clearly
• Team player who thrives in a collaborative environment
• Fluent in English (Dutch is a plus)

What’s in It for You?

• Salary: €74.000 - €88.000 (based on 40 hours per week)
• Hybrid work: 2 office days per week (Tuesday & Wednesday)
• Work on a high-scale authentication system used by millions
• Long-term position with the possibility of a permanent contract

About our client

Our client is a renowned player in the e-commerce industry, offering a wide array of products to customers through an innovative and customer-centric platform.

They are dedicated to simplifying the online shopping experience and empowering businesses to succeed in a rapidly evolving digital landscape.

Join a team that values creativity, collaboration, and making an impact in the lives of millions.

This dynamic and inclusive workplace with plenty of opportunities for growth, the flexibility to innovate, a culture that celebrates success, and a supportive work environment, is a place where your ideas can truly make a difference.

Apply now

Is this the challenge you’ve been looking for? Apply on this vacancy or contact Gavin de Graaf via email at [email protected] or by phone at +31 6 15366790.