Blockchain Payments Integration - Backend Engineer (TypeScript)

Mid • Remote

14,000 - 20,000 PLN

Gdansk, Poland

Backend Engineer (TypeScript)

We're building a high-performance financial ledger connecting fiat payment rails and blockchains through service providers. We're looking for a backend engineer to work on integrations that bridge traditional banking (ACH, WIRE, SEPA) with on-chain stablecoins.

What You'll Work On

Building and maintaining services that connect Banking-as-a-Service providers to our network
Implementing on-ramp (fiat to tokens) and off-ramp (tokens to fiat) pipelines with strong idempotency guarantees
Designing queue-based processing pipelines for multi-step financial transactions
Working with identity/compliance infrastructure: KYC certificates, selective disclosure, encrypted attribute sharing
Publishing service metadata for decentralized discovery by wallets and other services
Writing integration tests against real APIs and a local blockchain node

Tech Stack

TypeScript / Node.js (ESM)
PostgreSQL
Vitest
Custom SDK ecosystem

What We're Looking For

Strong TypeScript skills with emphasis on type safety
Experience integrating with banking/payment APIs (ACH, wire transfers, BaaS platforms)
Comfort with asynchronous pipeline architectures (queues, retries, idempotency)
Understanding of blockchain concepts (token minting/burning, on-chain permissions, transaction signing)
Preference for integration tests over unit tests; ability to write tests that exercise real system behavior end-to-end
Familiarity with explicit resource management patterns (AsyncDisposable, structured cleanup)
Experience working with different third-party integrations

Nice to Have

Experience with KYC/KYB compliance flows and certificate-based identity
Multi-currency system design (FX, per-currency fee structures, decimal handling)

How We Work

Strong code ownership
Small team, high autonomy, direct impact on financial infrastructure

Straightforward Recruitment:
- We respect your time. Our 2-step recruitment process is designed to be efficient and meaningful.
- Flexible Work Environment: Work from anywhere. Align with sprint goals and deliverables - we trust you to manage your productivity.

gmi.software

gmi.software is a software development company specializing in building high-quality mobile applications, particularly with modern technologies such as React Native. The company partners with well-known consumer brands to deliver high-visibility digital products that drive user engagement and long-term brand loyalty. It emphasizes technical excellence, strong architectural standards, and the use of cutting-edge tools, including AI-assisted development solutions. gmi.software fosters a collaborative, cross-functional work environment where product, design, and marketing teams work closely together. The company values ownership, proactive problem-solving, clear communication, and respect for deep, focused work. It operates with a modern, remote-friendly structure and provides stable, long-term project engagement for its team members.

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