Senior Fullstack Software Engineer, Growth

Payrails is a global payment software company helping leading enterprises to take control of their payment operations and maximize performance. With deep experience in the payments space and firsthand knowledge of merchants' challenges, we’ve seen how fragmented, complex, and inefficient these systems can become. Now, we are setting a new industry standard for how enterprises around the world manage and optimize payments, with more control, visibility and flexibility than ever before.

Our vision is to reimagine payments from the ground up. We are building a deeply integrated meta layer that spans the entire payment lifecycle with a modular architecture. This helps us give leading brands building blocks to craft solutions to most complex operational challenges, tailor seamless customer experiences and grow their business.

We are backed by some of the world’s top investors including Andreessen Horowitz, HV Capital, EQT Ventures and General Catalyst, who share our mission to simplify payment complexity globally.

At Payrails, we’re committed to building a team of exceptional people - not just talented, but driven to build, solve, and deliver at the highest level. Excellence isn’t just a value here; it’s a way of working. We believe that great people thrive in environments where there’s trust, clarity, and shared purpose. We work openly and collaboratively, with deep respect for each other’s craft. Everyone is encouraged to understand the bigger picture - what we’re building, why it matters, and what stands in the way. When people have that context, they move faster, take ownership, and make better decisions. We care about creating a culture where people feel inspired to do their best work and a deep sense of responsibility to help us bring our vision to life. Success at Payrails means staying focused on the problems that matter most, and executing with purpose.

Payrails is a true tech company: our Product is designed by engineers for engineers. We believe in quality before delivery: our mission is to provide an outstanding Payment experience with a strong eye on automation, resilience, and scalability. Our engineering culture is focused on 3 main pillars: 

• We aim for operational excellence 

• We promote open communication and quick feedback

• We share knowledge and learn continuously

You’ll join a newly formed Growth team, working closely with Product, Marketing, and Data Science. This team’s mission is to drive user acquisition, engagement, and retention by blending engineering excellence with data-driven experimentation.

You’ll have the autonomy to shape the technical direction of our growth initiatives - from revamping our website and improving onboarding flows to building a reliable experimentation infrastructure that scales with our ambitions.

• Leading the design, development, and deployment of features that drive user acquisition, engagement, and retention.

• Architecting and implementing A/B tests to optimize product performance and improve conversion rates.

• Collaborating closely with Product, Marketing, and Data Science teams to identify and execute high-impact growth initiatives.

• Building and maintaining scalable, high-performance web applications using modern fullstack technologies.

• Developing and integrating APIs including CMSs

• Implementing analytics and event-tracking systems to monitor user behavior and measure experiment outcomes.

• Enhancing website performance, SEO, and overall user experience through engineering improvements.

• Driving technical best practices, improving system architecture, and mentoring junior developers.

• You have 7+ years of experience in fullstack development, preferably in a growth-focused or product-driven environment.

• You’re proficient in JavaScript/TypeScript, and have deep experience with React, Node.js, or similar frameworks.

• You have good backend development skills, including experience with APIs, databases (SQL/NoSQL), and cloud infrastructure (AWS, GCP, or similar).

• You have a solid understanding of A/B testing methodologies and experiment-driven development.

• You’re comfortable optimizing queries, managing APIs, and handling performance issues at scale.

• You have experience integrating third-party APIs, analytics tools, and tracking systems (e.g., Google Analytics, Mixpanel, Segment).

• You’re data-driven and passionate about leveraging engineering solutions to improve key growth metrics.

• You have proven track record of leading solutions end-to-end

• You have exceptional communication skills, with the ability to clearly articulate complex concepts to both technical and non-technical teams.

• High impact and high velocity environment with the most talented and ambitious people you will ever work with

• A chance to shape the story of a company and a category from the ground up

• Real ownership. You’ll have the freedom and trust to build, test, and take lead

• A product used by the best brands around the world

• Visa and relocation support for you and your family where required

• Hybrid working with an office in the heart of Berlin

• Regular team events, activities and off-sites

• Discounted Urban Sports Club membership

• Competitive salary and equity package

• 27 days of annual paid vacation