Job description

Company Description

InstaXchange is a licensed provider of financial services, specializing in fast and secure fiat-to-crypto, crypto-to-fiat, and online exchange operations. We ensure legal compliance and maintain a robust infrastructure to offer services like card payments, SEPA transfers, and issuing vIBANs to clients. Our non-custodial approach ensures a seamless onramp and offramp experience for our users.

Role Description

We're seeking an experienced Backend Developer to join our team working on a sophisticated fintech payment gateway platform that handles cross-border payments, cryptocurrency transactions, and multi-provider payment orchestration. This is a hands-on role where you'll be working with complex financial systems, third-party integrations, and high-stakes transaction processing. 

 Tech Stack 

 Core Technologies: 

 - Language: Python 3.x 

 - Framework: FastAPI 

 - Database: PostgreSQL with SQLAlchemy ORM 

 - Async Processing: asyncio, background tasks 

 - Caching: Redis 

 - Message Queue: Background job processing 

 Infrastructure & Tools: 

 - Git version control 

 - Alembic for database migrations 

 - RESTful API design 

 - Webhook systems 

 System Reliability 

 - Build robust error handling and logging systems 

 - Implement monitoring and alerting (Discord notifications) 

 - Handle edge cases in payment flows 

 - Debug and resolve production issues 

 - Optimize database queries for performance 

Required Skills & Experience 

Must Have 

 - 3+ years of Python backend development experience 

 - Strong experience with FastAPI or similar async frameworks (Flask, Django) 

 - Solid understanding of SQLAlchemy ORM and database design 

 - Experience with PostgreSQL and writing complex SQL queries 

 - Understanding of async/await patterns in Python 

 - Experience with REST API design and implementation 

 - Strong grasp of transaction management and ACID principles 

 - Experience with Redis for caching and locking 

- Knowledge of webhook systems and callback handling 

- Understanding of idempotency in distributed systems 

 Strongly Preferred 

 - Experience in fintech, payments, or financial services 

 - Understanding of cryptocurrency transactions and wallets 

 - Experience with background job processing 

 - Understanding of state machines and workflow orchestration 

 - Experience with Alembic migrations 

Technical Challenges You'll Face 

 1. Complex State Management: Managing transaction states across multiple providers with different status models 

 2. Idempotency: Ensuring operations are safely retryable without duplicate charges 

 3. Provider Abstraction: Building flexible abstractions that work across different payment providers 

 4. Error Recovery: Implementing robust retry mechanisms and error handling 

 5. Financial Accuracy: Ensuring perfect precision in calculations and conversions 

 6. Performance: Optimizing database queries for high-volume transaction processing 

 What We Offer 

 - Work on real-world fintech challenges with significant impact 

 - Exposure to multiple payment technologies (crypto and fiat) 

 - Learn about international payments and compliance 

 - Contribute to critical financial infrastructure 

 - Opportunity to work with cutting-edge payment providers

Please Provide:

1. Your resume/CV 

2. GitHub profile or code samples 

3. Brief explanation of your experience with: 

 - Payment systems or fintech 

 - Complex transaction workflows 

 - Third-party API integrations 

 - Financial calculations and data accuracy

Note: Our recruitment process includes AI-assisted verification. Please submit only genuine CVs, as falsified or AI generated submissions will be automatically flagged.