Senior Backend Developer (PHP)

• Participate as a Senior Backend Developer in one of four agile Scrum teams focused on in-platform payments, onboarding, and core product innovation.
• Design scalable architectures and implement modular services built for long-term maintainability.
• Mentor junior and mid-level developers, shaping technical strategy and making key architectural decisions to ensure 99.99% availability and industry-leading security.
• Contribute to projects such as:

• In-platform payments: Expanding beyond traditional e-commerce to serve platforms where money moves in new ways.
• Onboarding & compliance: Developing intuitive user journeys while upholding strict security standards.
• Scalability & microservices: Transforming legacy systems into agile, modular components for tens of millions of transactions across Europe, the UK, and beyond.
• Beyond payments: Developing APIs, web applications, and tools that empower platforms to grow and innovate.

• Work with a modern tech stack including PHP, Laravel, Symfony, MySQL, Redis, Docker, Kubernetes, and CI/CD pipelines.

Tech you'll use & how you'll lead

• You'll work with a modern stack including PHP, Laravel, Symfony, MySQL, Redis, Docker, Kubernetes, and CI/CD pipelines.
• You'll design and implement scalable, modular services built for long-term maintainability.
• You'll help shape technical strategy while mentoring junior and mid-level developers.
• You'll contribute to key architectural decisions that ensure 99.99% availability and industry-leading security standards.

This is your chance to join a vibrant, knowledge-sharing community where every line of code directly impacts millions of users. Together, we'll push the boundaries of what's possible in fintech.

3 reasons you should join our backend team:

1. Engineer for reliability and scale - design and maintain a high-availability platform processing millions of secure transactions daily across Europe.
2. Work with robust architecture - contribute to a backend designed for accuracy, security, and long-term maintainability by creating and optimizing (micro)services and improving database performance.
3. Be part of a focused, skilled team - collaborate with 25+ experienced engineers in agile teams, sharing knowledge and solving complex technical challenges in the world of payments.

What started as five people, a small office, and a few nerf guns has grown into one of Europe's fastest-growing fintechs. With 150+ colleagues, offices in Delft, Berlin, and London, and Worldline as our partner, we offer the perfect mix: the power of a global leader with the energy of a scale-up.

At Online Payment Platform, we build the technology that powers the next generation of e-commerce. From eBay Kleinanzeigen to Ikea, tens of millions of users depend on our systems to process payments securely around the clock. This is your chance to join a vibrant, knowledge-sharing community where every line of code has a direct impact on millions of users.

Your track record tells us

• Deep experience with PHP and MySQL in high-stakes environments.
• Mastery of Laravel and/or Symfony frameworks.
• Proven track record with high-traffic platforms and microservices.
• You don't need to look up CI/CD, Docker, or Kubernetes, they're second nature to you as well as cache, queue, scalability, optimization and performance solutions. If you're just as comfortable with Redis, Queues, and scalable microservices, we might even let you choose the next game for team night .
• Ability to communicate complex technical concepts clearly across different departments.
• Residing in the Netherlands.

We provide a total yearly salary of up to €95,000, a modern and flexible hybrid workplace, 24 vacation days plus 2 "supercharge-me" days, a 12-month contract with the possibility of permanent extension, and all the tools you need (MacBook, home office setup, NS Business Card). Enjoy an attractive bike plan for those working 24 hours or more, a developers-only office at Lange Geer 26 in Delft, catered lunches, and regular team drinks.