Senior Software Engineer

Xsolla • Montreal, QC

45d • $100,000 - $140,000

About The Position

We're looking for a Senior Software Engineer to join our Payments team and help build, maintain, and scale the platform that processes payments and PSP integrations for game developers and players globally.
You'll work on high-load, mission-critical systems — designing event-driven architectures, optimizing transaction flows, integrating with global payment providers, and ensuring our platform stays reliable under real-world pressure. You'll have real ownership, real impact, and real engineering challenges to solve.
If you care deeply about correctness, reliability, and clean systems — and you want your work to matter to millions of users — this role is for you.

Requirements

• 4+ years of backend engineering experience in production-grade systems — preferably within Fintech, Banking, or Payments — with strong proficiency in PHP and/or Golang; candidates with equivalent experience in comparable languages will be considered.
• Hands-on experience with payment processing and PSP/acquirer integrations
• Solid understanding of end-to-end payment flows: authorization, capture, refunds, chargebacks, and reconciliation
• Strong grasp of OOP principles, design patterns, and clean architecture
• Proficiency in SQL, database design, and query optimization
• Experience with message queues (RabbitMQ, Kafka) and caching layers (Redis)
• Strong fundamentals in algorithms and data structures with practical application
• Experience writing unit and integration tests as a core part of your workflow

Nice To Haves

• Knowledge of PCI DSS compliance and secure payment data handling
• Familiarity with 3D Secure (3DS) authentication protocols
• Experience with tokenization and payment security best practices
• Hands-on experience with Kubernetes and Google Cloud Platform (GCP)
• Familiarity with the ELK stack for monitoring and log analysis
• Experience with high-load, mission-critical distributed systems
• Frontend exposure with Angular or React is a bonus

Responsibilities

• Design, build, and maintain backend services for payment processing
• Integrate and support payment service providers (PSPs) and acquirers such as Adyen, Checkout.com, JP Morgan Chase, and others
• Build scalable, event-driven architectures to handle high-throughput, low-latency payment workloads
• Write clean, testable, well-documented code with strong unit and integration test coverage
• Optimize database queries and schema design across MySQL
• Contribute to system design discussions, code reviews, and technical decision-making
• Monitor system health, troubleshoot production issues, and drive continuous improvements in observability and reliability
• Participate actively in CI/CD pipeline improvements and deployment processes
• Mentor junior engineers and contribute to a culture of engineering excellence

Benefits

• We are passionate about fostering a supportive environment for our team, so we prioritize the physical, mental, and emotional well-being of our employees and their families through a comprehensive Benefits Program. This includes medical, dental, and vision, PTO, and a personalized career roadmap for each employee. By investing in professional development through training and educational opportunities, we ensure that our team thrives both personally and professionally. Together, we’re not just building a business; we’re cultivating a community that values creativity, collaboration, and the transformative power of play.

What This Job Offers

• Job Type: Full-time
• Career Level: Mid Level
• Education Level: No Education Listed
• Number of Employees: 501-1,000 employees