Senior Software Engineer

About Upsun (formerly Platform.sh)
Upsun is the cloud application platform humans and robots love. It is built for today’s hybrid teams, where AI agents write and test code and humans focus on solving the problems that really matter. Developers, DevOps engineers, and platform teams use Upsun to build, ship, and scale confidently without wrestling with backend infrastructure. We give you your time back. You get:
Predictable performance, even at scale
Secure, compliant environments by default
Real-time observability and profiling built in
Cloning, configuration, and provisioning in seconds
AI-ready features that plug directly into your stack
The name says it all. "Up" means uptime, reliability, and acceleration. "Sun" reflects our follow-the-sun-support, a 24x7, globally distributed support team keeping the lights on while you rest. Our core belief is that software should power brighter solutions and greater innovation.
Upsunners are a remote, global workforce, and we thrive in a multicultural team. We are committed to open source and an open, welcoming environment. Our team spans the globe and the experience spectrum.
What's our commonality, our cultural fabric? A curious spirit and a thirst for knowledge; an eagerness for innovative ideas and cultures. We believe we can build anything together in an environment that frees you to do your best work.
Our values:
🌿 We make a positive impact.
✨ We aim for the stars.
💚 We care for each other.
Impact of a Senior Software Engineer
As a Senior Software Engineer at Upsun, you will design and build the backend services behind our customers' billing, and help the engineers around you do their best work. Billing is your main focus: invoices, taxes, usage reporting, and the integrations that connect our platform to the commercial systems behind it.
You will own complex components end to end, make the design decisions behind them, and spot where they can be improved. Working closely with Finance, Product, and Support, you will turn commercial requirements into reliable services. This is a hands-on role: most of your time goes into designing and writing code that customers rely on every time they're billed.
What to expect
Design and build billing services: Design, build, and maintain backend services and API integrations in Go that connect our platform to external billing systems.
Own complex features end to end: Lead the design and delivery of usage-based billing features such as usage aggregation, estimates, usage alerts, and invoicing, from technical design to production.
Make sound design decisions: Shape the architecture of the components you own, weigh trade-offs, and balance short-term delivery with long-term reliability.
Solve hard problems: Troubleshoot complex issues across distributed services and external APIs, and fix root causes, not just symptoms.
Improve what you own: Spot gaps in reliability, security, observability, or process within your area, then propose and deliver practical fixes.
Protect customers and data: Contribute to anti-abuse measures and apply security best practices to sensitive customer and payment data.
Mentor and review: Support other engineers through code review, pairing, and mentoring, and help keep the bar for quality high.
Work across teams: Partner with Finance, Product, Support, and other engineering teams, communicating clearly and asynchronously across multiple time zones.
What you bring
Go experience: Deep professional backend development in Go, building services in distributed systems.
System design: Experience designing backend systems and making architecture decisions that held up in production.
Relational databases: Strong experience with relational databases such as PostgreSQL or MySQL/MariaDB, including data modeling, migrations, and performance.
Complex integrations: A track record of integrating third-party APIs where you don't control the contract, the rate limits, or the uptime, with strong instincts for idempotency, retries, and consistency.
Accuracy and testing: Experience in domains where correctness matters, such as billing or payments, and a commitment to testing failure paths.
Security awareness: A solid understanding of common vulnerabilities and of security considerations in payment and billing systems.
Mentoring: Experience mentoring engineers or guiding technical work on a team while staying hands-on.
Interest in billing: You enjoy working on billing and financial systems and want to make them your focus.
Clear async communication: You write clearly and can build agreement across a distributed team.
Bonus
Experience with usage collection and aggregation.
Experience with commercial billing platforms or e-commerce systems, including open source ones.
Experience with event-driven systems, message queues, or transactional outbox patterns.
Experience with multi-currency and precise decimal handling.
Background in PaaS development.
Experience with anti-abuse or compliance-related features.
Where we hire
At Upsun, remote work isn't just a trend - it's our foundation. The freedom of remote work with the support of a diverse, global team has been our successful model for over a decade. Our culture celebrates flexibility and collaboration, and while we have team members in over 30 countries around the globe, we are currently focused on hiring for this role in Canada, France, Germany, Spain, the United Kingdom, and the United States. Although we’re unable to provide visa sponsorship at this time, we welcome applications from all qualified candidates who are legally authorized to work in these countries.
How we hire
We know that a great hire won’t meet every requirement that we’ve outlined. If you can see yourself elevating the team, we want to hear your story. Few of us would be here had we not taken a chance.
You can expect 4 interviews on Google Meet to follow t