Senior Platform Engineer

Why Polar? It's never been easier to build, ship and scale software. But it's never been harder to monetize it. Modern startups look fundamentally different than prior generations: Smaller teams Exponential revenue growth relative to headcount Higher variability in costs (LLMs) requiring more frequent pricing iterations Laser focused on product development and distribution Delegating and automating everything that is boilerplate – be it in their codebase or business operations. Exceptional billing primitives, APIs and SDKs are essential, but delightful integration is not enough. Startups need a billing platform designed for their speed of iteration. Combining billing and analytics in one platform to offer customer- and feature unit economics in real-time. Offering built-in pricing and cost insights, simulations and optimizations while simultaneously handling international compliance, tax management, fraud prevention and more. That's Polar. We're building the next standard for applied AI startups. Join our small, talented and engineering-led team across Europe as we build the infrastructure powering the next generation of software companies. We focus on shipping at high velocity to serve startup founders scale their businesses. Everything else is secondary. Role & responsibilities: What you will do We’re hiring a Senior Platform Engineer to architect and evolve the Polar platform - ensuring the system remains fast, resilient and operationally sound as we scale. Polar operates as a merchant of record, meaning our platform sits directly in the critical path of global payments, billing infrastructure and financial workflows. Reliability, uptime and correctness are essential - while still maintaining the ability to move quickly and ship product improvements. You’ll work across the platform, application and infrastructure layers that power Polar - from core infrastructure and observability, to shipping new core primitives that are used within the platform by our customers. In close partnership with the team, you’ll ensure the system scales to handle increasing traffic, architectural complexity and regulatory demands without compromising stability, performance or developer velocity. This role is ideal for someone who loves to deal with both infrastructure and cloud components with reliability as a product requirement and scalability as an architectural discipline. As well as doing deep systems engineering experience with a passion for building reliable, scalable platforms and empowering engineering teams through strong abstractions and automation. While this role focuses primarily on the foundational layers of our platform, we value engineers who are comfortable moving across the stack when needed to ship quickly and maintain momentum. You’ll work with the team to: Ensure Platform Reliability & Uptime: Design and evolve systems that maintain high availability, predictable performance and operational stability. Drive improvements in uptime, resil