Staff Backend Engineer Financial Ledger

Location: Europe (Remote)

Company: Voyagu

Product: Radar

The Mission

Voyagu is a travel-tech company evolving Radar, our core platform, into a multi-agency SaaS system. The Financial Core is the spine of this transformation. We are looking for a Staff Backend Engineer to become the long-term technical owner of the system responsible for revenue calculations, payments, ledger-style events, and deterministic profit.

The Context

Active Evolution, Not a Blank Page This stream is already in motion. We started the Financial Core evolution a couple of months ago and have already defined the core architectural direction, introduced a ledger foundation, and implemented initial domain event flows.

By the time you join, V1 will likely be in advanced implementation or early testing. Success in the first 3-6 months is not about inventing architecture from scratch, but about taking hands-on ownership of an actively evolving system, stabilizing V1, and identifying gaps to drive the direction toward V2.

What You Will Work On

• Technical Ownership: Independently drive the direction of the Financial Core, challenge assumptions, and work closely with finance and engineering leadership.
• System Integrity: Validate the correctness of lifecycle flows and reconciliation behavior.
• Financial Logic: Handle ledger-style economic events, revenue/profit recognition, cost normalization, and client/supplier balances.
• Architecture: Improve the trustworthiness of the financial model and ensure strict financial invariants in a distributed, event-driven environment.

Tech Stack

• Primary: Python (backend services), PostgreSQL (complex relational modeling).
• Cloud: AWS (Lambda, SQS, S3), AWS CDK (Infrastructure as Code).
• Focus: Data correctness and transactional consistency.

What We Are Looking For:

• 8+ years of backend engineering experience, with significant time spent owning financial or transactional domain logic.
• Domain Depth: You have built real financial systems (payment platforms, billing infrastructure, ERP, or subscription platforms).
• Experience with "Live" Evolution: You know how to evolve complex production systems responsibly without breaking existing flows.
• Architecture & Hands-on: This is a hands-on ownership role, not a purely theoretical exercise.

Mandatory Domain Requirements:

We expect you to have deep, practical experience with:

• Ledgers and Reconciliation: Building systems that ensure deterministic correctness.
• Financial Operations: Reasoning about liabilities, revenue/profit recognition, and money flows.
• Complexity: Ability to describe and manage high-level financial domain complexity (e.g., multi-currency, complex tax log