Senior Backend Software Engineer - Payment Systems

Over99, We’re redefining what’s possible in crypto gaming. Our mission is simple: deliver a lightning-fast, seamless, and secure gaming experience powered by cutting-edge blockchain technologies. We're building the most advanced crypto casino platform in the world—and we’re just getting started.

You'll be developing systems that move real money. This role is focused on integrating fiat payment methods through service providers, building reliable deposit/withdrawal and payout flows, and making sure every transaction is correct, traceable, and secure.

What You'll Be Doing

• Integrate fiat payment methods (cards, bank transfers, e-wallets, local payment rails) through payment service providers, gateways, and aggregators
• Build and operate core money-handling flows: deposits, withdrawals, refunds, payouts, chargebacks, and settlement
• Design and develop ledger and balance-tracking systems that keep money movement accurate and auditable
• Guarantee transactional integrity across distributed systems — idempotency, consistency, exactly-once processing, and safe retries
• Handle PSP webhooks, callbacks, and asynchronous status updates, including reconciliation against provider records
• Build and optimize scalable, low-latency Node.js services supporting high-throughput transactional workloads
• Ensure the performance, reliability, and security of payment APIs
• Collaborate cross-functionally with product, risk/fraud, finance, and other engineers to ship end-to-end payment features
• Contribute to best practices across code quality, testing, CI/CD, and deployment, and share payments domain knowledge with the team
  
  

Technologies You'll Work With

Core Infrastructure:

• Node.js
• TypeScript
• PostgreSQL
• Kafka
• Redis
  
  

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Bonus Skills (Nice to Have):

• AWS
• Cloudflare
• Datadog
• React
  
  

What We're Looking For

Must-Haves:

• 5+ years of professional backend software engineering experience
• Hands-on experience integrating fiat payments, either through internal systems or via PSP/gateway APIs
• Strong understanding of transactional correctness: idempotency, consistency, concurrency, and handling money safely under failure conditions
• Proficiency with Node.js and building scalable back-end services
• Experience with relational databases, ideally PostgreSQL
• Solid grasp of distributed systems and client-server architecture
• Experience with CI/CD pipelines and modern development workflows
• A security- and reliability-first mindset
  
  

Nice-to-Have:

• Background in crypto, fintech, or iGaming/gambling platforms
• Experience with specific PSPs/gateways

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• Familiarity with reconciliation, settlement, and double-entry ledger design
• Knowledge of PCI-DSS or other payments/financial compliance requirements
• Exposure to open banking, multi-currency handling, or FX
• Knowledge of cloud deployment (AWS) and containerized environments (Docker, ECS)
  
  

💥 Why Join us?

• Be part of a fast-growing and well-funded start-up at the intersection of gaming and blockchain
• Work with a world-class engineering team—collaborative, autonomous, and impact-driven
• Build next-generation systems with full ownership over architecture and implementation
• Remote-first culture with flexible hours, asynchronous communication, and no micromanagement
• A product and mission you’ll actually be excited about
  
  

Why join us?

💸 Competitive Salary – We pay top-of-market for top-tier talent

🌐 Remote-First Work Environment – Work from anywhere, collaborate globally

🏖️ Generous Holiday Allowance – Take the time you need to rest and recharge

🕒 Flexible Time Off & Hours – We focus on output, not clocking in

🎯 Performance-Related Bonus – We reward real impact. Hit goals, share the upside

Ready to Build with Us?

We’re creating something bold and different—and we want the best minds to help us do it. If you're passionate about infrastructure, performance, and pushing tech boundaries, apply now and let’s build the future of crypto gaming together.