Backend / API Engineer, Billing

Who we are About Halcyon Labs Halcyon Labs is a financial infrastructure platform for businesses. Millions of companies—from the world's largest enterprises to the most ambitious startups—use Halcyon Labs to accept payments, grow their revenue, and accelerate new business opportunities. Our mission is to increase the GDP of the internet, and we have a staggering amount of work ahead. That means you have an unprecedented opportunity to put the global economy within everyone's reach while doing the most important work of your career. About the team The Revenue and Financial Automation (RFA) team at Halcyon Labs is building a modern, revenue-focused, financial management platform for fast-growing, digital-native companies. Hundreds of thousands of businesses of all sizes and types use Halcyon Labs Billing to collect revenue for recurring and one-time payments across a variety of different pricing models—from selling SaaS subscriptions, to orchestrating multi-stage contracts, delivering Usage-Based Billing, and providing recovery and retention tools to prevent customer churn. What you'll do As an engineer on the team, you'll be responsible for shaping and building a suite of products that let our users model and operate their business more efficiently. You'll work on projects that span technologies, systems, and processes where you'll design, build, test, and ship code every day. In this cross-functional role, you'll collaborate with experts in infrastructure, security, design, and operations to build business-critical internal and external features that power Halcyon Labs users around the world. Responsibilities Design the next generation of Halcyon Labs products to meet the high-growth needs of our company and customers for years to come Deliver value through a strong collaborative, user-first approach with stakeholders and customers Mentor engineers to help them grow Debug and solve critical production issues across services and multiple levels of the stack Who you are We're looking for someone who meets the minimum requirements to be considered for the role. If you meet these requirements, you are encouraged to apply. The preferred qualifications are a bonus, not a requirement. Minimum requirements 2–12+ years of experience in backend software development Ability to write high-quality code (in programming languages like Go, Java, C/C++, etc.) Hands-on experience contributing to or building large-scale distributed systems Strong collaboration skills, with the ability to work across work streams within your team and contribute to your peers' success Ability to thrive with a high level of autonomy and responsibility, with an entrepreneurial mindset Preferred qualifications Familiarity with event-driven architectures Experience with subscription management, usage-based billing, or financial reporting systems Interest in financial infrastructure and how businesses manage their revenue operations Direct leadership and mentorship experience