Senior Product Engineer (Europe)

Remote from: Europe
Annual salary: Undisclosed
Salary information is not provided for this position. Check our Salary Directory to estimate the average compensation for similar roles.
Department: Software Engineering
Employment type: Full Time,
Job posted: 16 Jun 2026
Apply before: 16 Jul 2026
Experience level: Senior
Views / Applies: 33 / 7

About company

About Polar

Polar is the financial layer for a new generation of intelligent software.

Computer Software
2023

Actively Hiring

AI Summary

Polar is an open-source monetization platform for developers, and they are hiring a Senior Product Engineer to join their remote-first team in Europe. The role involves shipping features across the full stack (frontend, backend, infrastructure) with high autonomy and a focus on fast iterations. Ideal candidates have 5+ years of experience, a startup background, and strong skills in React, Python, and cloud infrastructure. The team values speed, quality, and developer experience, with a culture of high ownership and minimal bureaucracy. Compensation is competitive but not specified, and the role offers equity, remote work, and a generous workspace allowance.

Role DNA

Job Complexity

Easy Hard

Pace & Pressure

Relaxed Fast-paced

Autonomy Level

Guided Full Ownership

Communication Load

Independent Highly Collaborative

AI Insight This role demands deep technical expertise across the full stack, a startup mindset, and the ability to ship high-quality code quickly with minimal oversight, making it highly challenging.

Salary Analysis

AI Insight The offered salary is not specified in the listing. Based on US market data for a Senior Product Engineer, the median salary is approximately $160,000 per year. However, since the role is remote in Europe, the actual compensation may vary by location. The position likely includes equity and other benefits, which can offset base salary differences.

Key Skills

React Next.js Python FastAPI Postgres Redis Cloud Infrastructure DevOps API Design Open Source

Cover Letter Sample

Dear Hiring Team,

I am excited to apply for the Senior Product Engineer position at Polar. With over 5 years of experience building and scaling software, including as a startup CTO, I am comfortable owning projects end-to-end. I thrive in fast-paced, autonomous environments and have a strong passion for developer experience and open source. My expertise in React, Python, and cloud infrastructure aligns perfectly with your stack. I look forward to contributing to your mission of empowering developers.

Sincerely,
[Your Name]

Possible Interview Questions

Describe a time you shipped a complex feature end-to-end across frontend, backend, and infrastructure.

At my previous startup, I led the implementation of a real-time analytics dashboard. I designed the frontend with React, built the backend API with FastAPI, and set up a data pipeline using Redis and Postgres. I also deployed it on AWS with auto-scaling. The project was shipped in two weeks, handling 10x the expected traffic from launch.

How do you handle trade-offs between shipping speed and code quality?

I believe in cutting scope before cutting craft. I prioritize delivering a well-architected, tested core feature, and then iterate quickly. For example, I might use feature flags to deploy early and gradually roll out, ensuring quality at each step while maintaining momentum.

Explain a challenging technical problem you solved recently.

We had a performance bottleneck in our billing system due to inefficient database queries. I optimized the queries, added caching with Redis, and implemented asynchronous processing with Dramatiq. This reduced latency by 80% and allowed us to handle 5x more concurrent users.

How do you contribute to team collaboration in a fully remote setting?

I make an effort to over-communicate via async updates on Slack and Notion, and schedule daily stand-ups for quick syncs. I also participate in pair programming sessions weekly and ensure that code is well-documented. I believe in building rapport through virtual coffee chats and team offsites when possible.

What is your experience with developer tools or monetization platforms?

I have built developer tools for API management and have experience with Stripe integration for subscription billing. I understand the importance of seamless API design and documentation for developer adoption. At Polar, I can leverage that to create a best-in-class monetization experience.

About Polar

It’s never been easier to build, ship, and scale software. Yet, it’s never been harder to monetize software. It’s a bottleneck for the future.

We’re building the open-source monetization platform to empower future one-developer unicorns. Going beyond great billing primitives to offer a more comprehensive platform for the next generation of developers to scale global businesses around their software.

Today, Polar is used and loved by thousands of developers from 100+ countries, and growing quickly.

About the Role

We’re hiring exceptional Senior Product Engineers to join our growing remote-first team in Europe. You’ll work across our entire stack to ship innovative features, enhancements and delights; obsessing over the developer experience and empowering them to scale their businesses. You’re very comfortable jumping between frontend, backend, and infrastructure to autonomously identify, build, ship and scale features.

We don’t have a lot of meetings, red tape or code reviews. We celebrate and optimize our organisation for shipping high-quality software fast – each engineer deploys countless times a day. So you’ll be given a lot of agency and autonomy to move fast towards our mission and serving our developer community.

What You’ll Do

Ship daily towards building the best monetization platform for developers in the world
Design, build, and ship features, enhancements and delights end-to-end – jumping between frontend, backend, and infrastructure
Collaborate with the team on architecture design, best practices, and ensuring high-quality code across our stack.
Contribute to scaling our infrastructure to handle growing traffic and complexity, including optimizing database queries and services for performance.
Continuously improve the quality of services and the overall developer experience.
Engage frequently with our developer community to identify pain points and solve them

About You

5+ years of experience building, shipping and scaling high-quality software.
You’re an ex-founder/startup CTO, open source maintainer or have side hustles
You ship fast and can solve any problem thrown at you
Strong proficiency with our stack or a variety of similar programming languages and ability + desire to quickly learn and pickup new tools.
Strong problem-solving abilities with an eye for developer experience
Experience with cloud infrastructure and multi-cloud environments.
Experience working with DevOps and comfortable maintaining, scaling and improving our infrastructure and participating in on-call
Excellent collaboration skills – comfortable working closely with a small, high-performing team. It’s a startup so we all have to lean-in across the board to
You care deeply about your craft – be it delightful animations, thoughtful edge-case handling, developer experience or performance optimizations.
(Bonus) Experience working with payments, billing, or developer tools

Our Stack

Frontend: React & Next.js with Tailwind CSS, Shadcn, TanStack Router and more.
Backend: Python (FastAPI), Postgres, Redis, Dramatiq,
Cloud: Cloudflare, Render & AWS

We Offer

Competitive compensation & equity.
Remote-first & open source culture. Work from anywhere in Europe (CET ±2 hours) and contribute to Polar in the open
Generous workspace allowance. Budget for an initial home office setup or co-working membership
High ownership. Help shape our product, architecture, open source libraries, SDKs, and developer experience from the ground up
Twice-yearly team offsites. We gather in our teammates’ cities to experience their local life, brainstorm the future, and write pseudo-code for what delightful billing should look like
Fast-moving and pragmatic environment. A small, senior team focused on momentum over perfection. We cut scope before we cut craft to keep shipping fast and iterating often
Mission with leverage. Build tools that empower other builders; your work compounds through theirs

About the Team

We’ve written books on FastAPI, built Shop.app & Shop Pay, helped ship the Battlefield React UI, and contributed to (and maintained) a lot of open source. We’re ex-founders and open source maintainers who care deeply about craft, velocity, entrepreneurship, and developer experience.

How to Apply

Submit your application with a suggestion on how to improve Polar’s developer experience today – we’d love to hear your ideas.

Process

Our entire process is fully remote, and all communication happens via email, GitHub issues/PRs, and video calls. Here’s what to expect:

Application Review – We’ll review your application and may reach out for a 15–30 minute video call with Birk (Founder)

Team Interviews – You’ll meet a few team members for a deeper technical and cultural conversation

Open Source Assignment – We’ll follow up with a GitHub issue scoped within Polar or one of our open source dependencies. You’ll collaborate with us asynchronously—from your first PR draft to final merge

Final Call – A video chat to discuss your work, your feedback, and suggestions on how to improve the DX of working with Polar

Reference Calls. We believe reference calls are great and help us confirm our impression and ramp up our understanding and abilities to ensure we hit the ground running productively.