Backend Engineer (Billing)

Solidgate

About The Position

Our Mission and Vision At Solidgate, our mission is clear: to empower outstanding entrepreneurs to build exceptional internet companies. We exist to fuel the builders — the ones shaping the digital economy — with the financial infrastructure they deserve. We’re building the #1 payment orchestrator in the world — and the names behind us prove it. Clients include Bolt, Ajax, Nova Post, MEGOGO. Trusted by giants like J.P. Morgan. Ranked #2 in the “Employer of the Year 2026” award by Forbes Ukraine. About the Team and Role You'll join the Billing team and become part of the effort behind one of the product's core modules — the one responsible for the invoicing cycle, payment retries, subscription management, and monetization. The team is actively building Billing v2 — a global overhaul and expansion of the subscription infrastructure — and has recently grown into a full-fledged Billing Stream. There's no legacy here — the team is building and launching the new Billing 2.0 module practically from scratch. Your team — 1 PM, 2 Senior Engineers, 1 Automation QA, 1 Domain Analyst. What you'll own Core Domain & Public APIs. Design and ship the foundational Products & Prices domain model and public APIs from scratch. Complex B2B Pricing at Scale. Build high-precision volume and graduated pricing engines for multi-tier enterprise billing. Bulletproof Platform Uptime. Decouple critical services from the Products API to eliminate single points of failure. End-to-End Revenue Recovery. Lead the automated retry engine across all invoices, recovering millions in failed payments. We rely on automated testing over manual QA — unit, integration, functional, and e2e tests are a core part of how we ship and scale safely. We code in Go, and we're looking equally for experienced Go engineers and strong switchers from Java, Kotlin, Python, or PHP.

Requirements

2+ years of backend engineering experience (Go/PHP/Kotlin/Java/Python/Node.js)
Experience covering code with tests: unit, integration, functional, e2e
Strong understanding of high-load system design principles
Experience with PostgreSQL and queues or streams
A proactive, communicative, independent, and result-oriented mindset

Nice To Haves

Experience with payment systems or in fintech / financial services
Kafka
AWS services
CI/CD pipelines

Responsibilities

Design and ship the foundational Products & Prices domain model and public APIs from scratch.
Build high-precision volume and graduated pricing engines for multi-tier enterprise billing.
Decouple critical services from the Products API to eliminate single points of failure.
Lead the automated retry engine across all invoices, recovering millions in failed payments.