Application Engineer II

Mollie is building payments and money management products designed to be simple, scalable, and dependable for more than 300,000 businesses across Europe. With 950+ employees across 14+ locations, the company works in small teams with real ownership, autonomy, and a balanced environment focused on long-term impact.

Build with us

Since 2004, we've had one clear goal: to make payments and money management effortless for every business in Europe. Today, more than 300,000 companies use Mollie to get paid, manage money and grow – with products designed to be simple, scalable, and dependable. With 950+ Mollies across 14+ locations, we care deeply about autonomy and craft. So we work in small teams, with real ownership, and we trust you to make the right decisions. We're building for the long term, so we provide the tools you need, processes you can rely on, and a balanced work environment to help you do work you're proud of.

Your impact

At Mollie, data and money movement are at the heart of everything we do — and the engineers who build and maintain these systems are central to our mission.

As an Application Engineer II, you will work on systems that operate at the core of Mollie's platform — from the financial infrastructure that underpins every payment we process, to the data products that help our merchants grow, protect their revenue, and optimise their performance. The work is high-stakes, high-ownership, and highly visible. You will be building systems where correctness, reliability, and scale are non-negotiable — and where the things you ship directly impact more than 300,000 businesses across Europe.

This is not a maintenance role. You will be joining a small, fast-moving team with a clear and ambitious mandate, working in a delivery-first environment where you take ideas from concept to production. You will have real end-to-end ownership, collaborate closely with engineers, product managers, and stakeholders across domains, and contribute to some of the most strategically important work happening at Mollie right now.

What you will be doing:

• Design, build, and maintain backend systems and APIs that operate at high scale and high frequency — where performance, fault tolerance, and reliability are critical.

• Take ownership of features end-to-end, from architecture and estimation through to delivery, production support, and continuous improvement.

• Contribute to ambitious migration and modernisation initiatives, decoupling legacy dependencies and building cleaner, more scalable foundations for the future.

• Transform complex technical and business requirements into well-designed, production-ready solutions — working closely with product and engineering stakeholders to shape what gets built and how.

• Participate actively in agile ceremonies including brainstorming, estimation, and sprint planning, bringing both technical depth and a product-first perspective to the table.

• Identify and resolve complex issues across distributed systems, applying creative problem-solving to challenges that sit at the intersection of engineering excellence and real merchant impact.

What you will bring:

• 5+ years of backend engineering experience, with strong proficiency in Java and ideally exposure to PHP; experience with Go, C#, or Python is also valued.

• Experience building and maintaining large-scale, high-volume systems — with a solid understanding of distributed systems, queuing, caching, concurrency, fault tolerance, and scalability.

• A background in financial systems, payments, or data-intensive applications is a big plus — you understand what it means to build systems where correctness, reliability, and performance are non-negotiable.

• End-to-end ownership mindset — you don't just execute tasks; you take initiative, shape ideas with a product-first approach, and think in terms of outcomes for merchants and the business.

• Strong communication skills, with the ability to work effectively with both technical and non-technical stakeholders across domains.

Grow your way

At Mollie, growth is personal. We believe everyone should have the chance to develop their skills, explore new challenges and shape their career on their own terms.

You'll get regular feedback and performance reviews to support your development, with fair and transparent salary reviews along the way. Many Mollies move into new roles or take on new projects to stretch themselves, and we actively hire from within to help you take the next step.

No matter if you're aiming for promotion, exploring a different career path or building new skills, you'll be supported with the tools, trust and opportunities to grow your way.

AI at Mollie

We believe in Always Be Shipping, and AI brings that philosophy to life across every team, every role, every day.

AI is core to how we build. It helps us move faster, simplify work and make smarter decisions, creating real impact for the businesses we serve. We're looking for people who are excited to use AI to shape the future of finance with us.

Kindly note that relocation support is not offered for this role.

Benefits

• 20 days working from abroad

  Enjoy the flexibility to work from abroad for 20 days a year (excluding high risk countries).

• Wellbeing Budget

  Enjoy €60 per month net towards taking care of yourself.

• Lifestyle and Health Support

  Reach out for coaching and support whenever you need it via OpenUp.

• 26 holiday days

  Time to relax. Plus an extra 2 days off in between 27 and 31 December.

• Commute options

  Receive an NS Business Card and participate in our bike lease plan.

• Birthday off

  It’s your special day! Why spend it at the office?

• WFH Equipment Budget

  One off budget of €400 for new hires.

• Hybrid working

  With WFH and Internet allowance at €60 a month.

• Discounted Lunch

  Hot and cold meals plus snacks available each day for less than €4 and only pay when you use the service.

• Health Insurance

  Insure with ONVZ or receive €125 net towards your own insurance.

• Annual Mollieverse event

  All Mollies get together, connect and have fun.