Senior Backend Engineer, Payments

About Arbor

Arbor builds payment infrastructure for marketplaces: split payouts, escrow and instant settlement across 30 countries. The team is 140 people, profitable since 2025, with offices in London and Lisbon.

The role

You will join the Ledger team, five engineers who own the double-entry ledger, payout scheduling and reconciliation. The work is correctness first: every penny accounted for, every retry idempotent.

What you'll do

• Design and ship services in Go on Postgres and Kafka

• Lead the move from nightly to real-time reconciliation

• Review designs across teams that touch money movement

• Mentor two mid-level engineers

What you bring

• 6+ years building backend systems, 2+ in payments, banking or another domain where errors cost money

• Strong SQL and data modelling; you have opinions about isolation levels

• Calm on-call habits and clear written communication

Package

£85,000–£100,000 base, 0.05% equity, 30 days holiday, 2 days a week in the Farringdon office.

Process

A 30-minute call with Priya, a take-home system design (paid, 3 hours), a technical conversation with two engineers, and a values chat with the CTO. Two weeks from first call to offer.