Senior Software Engineer - Billing; VAT & Invoicing

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Perk (formerly Travel Perk) is the intelligent platform for travel and spend management. Built to tackle the time‑consuming, manual work that gets in the way of real work, our tools automate everything from travel bookings to expenses, invoice processing, and more. By eliminating this shadow work that wastes hours, erodes morale, and saps innovation, we’re on a mission to power real work, with real impact.

We're trusted by more than 10,000 companies worldwide, including Wise, On Running, Breitling, and Fabletics. We tackle the 7 hours of lost productivity per employee each week, a $1.7 trillion problem.

Founded in 2015, Perk has grown into a global company of more than 1,800 people across 12 offices globally, with headquarters in London and Boston. We combine innovation, control, and simplicity to transform how businesses work and how people feel at work.

At Perk, we’re driven by our values—being an owner, delivering a 7‑star experience, and working as one team. We value curiosity, purpose, and mindset, not just knowledge, to unlock the power in your potential.

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The billing team owns tax determination, invoice issuance, invoice collection, and deferred payments. Right now the team is in the middle of its most significant technical work: migrating tax determination to a third‑party integration, re‑architecting invoice issuance for async processing at scale, and automating a previously manual invoice collection process into a fully self‑serve service, with AI at its core. There's also a growing stream of product‑facing, frontend work as we look to improve the end‑to‑end billing experience.

If you want real ownership of a domain that matters, in an engaged team that values teamwork, this is the team.

At Perk, we know that we feel most fulfilled when we can own the problem and the solution. This means taking responsibility for the entire lifecycle of a feature, from being part in understanding what our customers’ pains are with our product team, design documents, coding to deployment, and measuring impact. You will see how your technical decisions move the needle for our customers daily.

We prioritize autonomy and pragmatism, giving you the space to solve complex problems without unnecessary friction. Engineering excellence is measured by the reliability and simplicity of the systems you build to power a global platform.

At Perk, we believe the best work happens when great people come together in small teams, with a shared sense of purpose. You'll join a cross‑functional squad where you have real ownership of a piece of Perk's domains, a genuine say in what gets built, and the autonomy to make it happen. Each team decides how to contribute to Perk's company goals.

We care about impact, and we trust our people to deliver it.

AI is embedded in how we work and what we build. On the engineering side, it spans the whole workflow: our Notion, Jira, Git Hub and Slack are AI‑connected so you get up to speed fast, and day‑to‑day it helps with specifying features, writing and reviewing code, and automated AI PR review on every pull request. When something goes wrong in production, AI surfaces context across systems quickly.

We also embrace agentic coding, using AI as an active collaborator, not just a prompt‑by‑prompt co‑pilot.

We expect candidates to use AI tools in our coding interviews. The bar is understanding your code and owning what you produce.

• Shape the bigger picture. You won’t just build features, you’ll refine the what to build and why. At Perk, senior engineers are expected to go beyond the technical solution and focus on the problem itself. You’ll contribute to your squad’s quarterly goals and long‑term vision alongside your Product Manager and Engineering Manager.
• Architect for today and tomorrow. When a big change is needed in how our platform works, you’ll be the one writing the design documents that lay the foundation. You’ll…