Senior Backend Developer (Payment Gateway Aggregator) Offline

We’re looking for a Senior Backend Developer to help build and scale a high-load payment gateway aggregator for a fast-growing iGaming platform focused on the Asian market.
You’ll work on integrating multiple payment providers, ensuring seamless transaction flows, and building a system that automatically handles failures by switching between gateways.
If you enjoy smart engineering challenges, taking ownership, and building reliable systems without heavy bureaucracy — we’d love to connect!

How You’ll Contribute

• Design and develop the backend architecture for a high-load payment aggregator.
• Integrate multiple payment systems and APIs to ensure smooth and uninterrupted payment processing
• Build and scale microservices to handle large volumes of payment transactions (Node.js, NestJS, Kafka/gRPC). 
• Optimize PostgreSQL databases to handle large volumes of transaction data efficiently
• Set up and fine-tune AWS infrastructure (S3, Lambda, RDS, EC2, CloudFormation, CloudWatch) for high availability and performance. 
• Implement CI/CD pipelines, monitor system health, and ensure secure financial operations.
• Build fallback mechanisms between payment gateways to maintain uninterrupted payment processing.

What Makes You a Perfect Fit

• 6+ years of hands-on experience building server-side solutions with Node.js and NestJS.
• Mastery of microservices and async processing (gRPC, Kafka).
• Deep experience designing and optimizing scalable, high-load systems 
• Pro-level AWS knowledge (S3, Lambda, RDS, EC2, CloudFormation, CloudWatch).
• Deep expertise in PostgreSQL—designing and tuning databases for large-scale data.
• Strong TypeScript skills and a commitment to clean, reliable code.
• Familiarity with monitoring tools and load-balancing solutions.
• Comfortable taking ownership and driving things forward independently

Nice-to-Haves

• Team lead experience or interest in mentoring others
• Background in payment systems or financial platforms.
• Knowledge of security and cryptography for protecting sensitive data.

• Experience with horizontal scaling and database distribution strategies like sharding or replication

   

Hiring Process

Just two steps: a 30–40 min intro call with our Talent Partner to get to know you and share project details, followed by one technical interview. We’ll cover your experience, project details, and the challenges we’re solving. We value your time and aim to move fast.

Your next challenge is waiting. Let’s connect, talk about the impact we can make, and see if we’re the right fit for each other!

Who We Are

Umber is a full-cycle product agency founded in 2018. We started as a design-driven company and now build complex finance systems from the ground up. Our current focus: payment solutions, trading platforms, and tools for professional investors and traders.

We’re a small, ambitious, senior-level team working with top-tier financial clients. We’re passionate about finance, trading, and creating systems that don’t just work — they scale and shine under pressure. Check us out at https://umber.tech.

Why Join Us

• Hardcore engineering challenges — real-time trading, high-load systems, financial-grade security
• Small team, no bureaucracy — you’ll work closely with the CTO and make architecture-level decisions
• Flexibility — fully remote, Eastern European time zone overlap
• Mentorship and space to grow — if you’re good, we’ll make you great
• Impact — your code goes live, fast. You’ll shape the core of the product