Senior Product Engineer (Backend) - London

About Sequence

If you join Sequence, you'll help build the platform that lets companies get paid - we’re already processing $1bn+ in annual invoice volume and growing fast.

We're building the AI-powered revenue platform for modern finance teams, replacing fragile spreadsheets and legacy systems with software their teams love using.

Cognition, incident.io, MoonPay, and 100+ other high-growth companies trust us to handle their entire revenue cycle across quoting, billing, and revenue recognition.

Founded by repeat entrepreneurs, we hit 10x ARR growth last year and just closed a $20M Series A led by 645 Ventures, alongside a16z and exceptional founders and CFOs from companies like Decagon, Klaviyo and Wise.

What's it like to work at Sequence?

Small team, big opportunity, real ownership. You'll do work that matters, have direct access to customers, and grow alongside the company.

If you want to do the best work of your career at a company that's scaling fast, we'd love to meet you.

What you'll be doing

We care deeply about the quality of the product we're building. We're looking for engineers who are ambitious and take ownership end-to-end: from identifying what to build, through shipping, to making sure it works for real customers.

Here’s what you might work on:

• AI-powered approval workflows. Enterprise deals need approval chains, but rigid workflows break when every company has different rules. You'll build flexible routing that customers configure in natural language - \"require VP approval for deals over $100k with annual terms\" - and turn that into deterministic, auditable business logic.




• An intelligent collections agent. Chasing late payments is tedious, manual work. We're building an agent you instruct in natural language (\"send a reminder at 7 days overdue; elevate at 14 days\"), which then runs the entire workflow autonomously.




• Scaling billing infrastructure 10x. We’re building revenue-critical infrastructure and currently rearchitecting our billing pipeline for an order of magnitude more throughput - rethinking storage strategies, horizontal scalability, and how we’ll handle 10x load without 10x cost.

We're a lean team growing to 20+ engineers. You'll have real influence on what we build and how we build it. Early enough to shape fundamental architecture. Late enough that customers depend on what you ship.

You'll design systems that process high-velocity event streams, make technical decisions that balance cost and performance at scale, and build infrastructure that never compromises on reliability.

This is business-critical infrastructure: a