back-end developer

Backend EngineerAt Chexy, we're reimagining how Canadians manage their largest expenses?like rent, tuition, and insurance?by transforming them into opportunities to build credit, earn rewards, and gain financial flexibility.We're the first platform in Canada that lets users pay nearly any bill using their credit card, while unlocking meaningful benefits like cashback, points, and credit-building tools. With $1B+ in annual payment volume and millions of transactions per month, we're building financial infrastructure that needs to be fast, reliable, and bulletproof.About the RoleWe're looking for a Backend Engineer to own and build payment systems in Chexy Engine, our core backend repository. You'll work on the systems that move money?payment inflows, outflows, ledgering, settlement, and direct integrations with card networks and banking systems.This role is about building clean, scalable, production-grade financial infrastructure. Every line of code you write will process real money for real people, which means your work needs to be precise, well-tested, and built for scale. You'll design and implement the payment systems that can handle billions in annual transaction volume.What You'll Be DoingBuild and maintain payment processing systems handling inflows, outflows, and multi-rail settlement in Chexy EngineDesign and implement ledger systems using double-entry bookkeeping principles to ensure financial accuracy and auditabilityDevelop and optimize direct integrations with payment networks (Visa Direct, American Express) and banking systems (e-Transfer, PAD, Bill Pay, etc.)Write clean, well-tested, production-grade code in NestJS and TypeScript following scalable architecture patternsDesign event-driven systems using Google Cloud Pub/Sub for reliable, asynchronous payment processingBuild APIs consumed by our web and mobile applications, ensuring performance and reliability at scaleOptimize database queries and schema design in PostgreSQL (Cloud SQL) using Prisma ORMImplement caching strategies with Redis to handle high transaction volumes efficientlyWrite comprehensive tests and participate in code reviews to maintain code quality standardsCollaborate with frontend, mobile, and infrastructure teams to ship features end-to-endParticipate in on-call rotations for production payment systemsWho We're Looking For2+ years of backend engineering experience, with some exposure to production financial systems, payment processing, or high-volume transaction systemsStrong experience with NestJS, Node.js, and TypeScript in production environmentsDeep understanding of relational databases (PostgreSQL preferred) including schema design, query optimization, and transactionsExperience with ORMs (Prisma experience is a plus)Proven track record building and maintaining high-volume APIs and microservicesUnderstanding of event-driven architecture and message queues (Google Cloud Pub/Sub, Kafka, RabbitMQ, or similar)Experience with financial systems concepts: ledgers, double-entry bookkeeping, reconciliation, idempotency, transaction integrityStrong grasp of Redis or similar caching technologies for performance optimizationExperience with payment processing, banking integrations, or fintech productsAbility to write clean, maintainable, well-tested code with strong attention to detailStrong communication skills and ability to collaborate across teamsSelf-directed with ownership mentality?you take pride in shipping reliable, production-grade systemsBonus PointsDirect experience with payment network integrations (Visa, Mastercard, Amex) or banking APIsExperience with Google Cloud Platform (Cloud Run, Cloud SQL, Pub/Sub)Familiarity with Terraform or infrastructure-as-code practicesExperience building ledger systems or working with accounting principlesKnowledge of Canadian payment systems (e-Transfer, PAD, Bill Pay)Experience with API documentation (Swagger/OpenAPI)Contributions to open-source projects in payments, fintech, or backend infrastructureBac