Application Engineer I
Confirmed on the employer's own hiring board on Nov 14, 2026. First seen by Alion on Nov 11, 2026. Mollie scores A on the Alion truth index.
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 250,000 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.
Sound like your kind of place? Let's build together.
Your impact
As an Application Engineer I in the Hosted Integrations team, you'll help bring e-commerce platform integrations that were built by external consultants back into Mollie's unified e-commerce gateway codebase. You'll work on key high-volume partner integrations, including Shopify, Wix, Lightspeed and Mirakl, and more to come, while we explore a native integration for Salesforce. This is primarily a backend role in Java, where you'll connect services into the wider Mollie ecosystem.
The work matters. By keeping high-volume payment processing smooth across major global e-commerce platforms, you directly support Mollie's commercial goals and partner relationships, and you remove financial friction for merchants. You'll have high visibility and a direct line to key revenue drivers. At this level, you move from individual tasks to owning small projects within the team, maintaining and extending the systems you work on, and speaking up when you need help to get unblocked.
You'll be part of the only engineering team in the Commercial Partnerships domain, so you'll have the chance to help shape the engineering craft there. You'll work with mature core gateway systems, help scale integration architectures, and learn alongside senior engineers who are stepping into technical leadership.
What you'll ship
Get up to speed on the e-commerce gateway system
Bring integrations built by external consultants back into Mollie's unified e-commerce gateway codebase
Streamline and maintain existing e-commerce integrations, so high-volume transactions are processed reliably
Deliver small, clearly defined projects within the team from start to finish
Write testable, readable code and contribute to documentation when needed
Monitor, maintain and extend the systems within the team's scope, and take part in support rotations with help from more experienced teammates
Share progress and blockers with the team and stakeholders, and track the outcomes of your work with relevant metrics
What you'll bring
3+ years of professional in software engineering experience
A strong professional background in full-stack software engineering
Proficiency in Java and object-oriented programming
Proficiency in React and/or React Native
Experience working with scalable applications or gateway systems
A good understanding of cloud environments, with Google Cloud Platform preferred
Excellent English communication skills
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.
Unlock your full potential and join us to eliminate financial bureaucracy
If you're excited by the idea of building what's next, for yourself and for thousands of businesses across Europe, we'd love to hear from you.
Apply with your CV (in English) using the form below.
Want a peek behind the scenes? Check out what life at Mollie is really like.
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.