Senior Backend Engineer (Payments)

Role Overview: We are looking for a Senior Backend Engineer to join our core payments team at Cellulant. You will be responsible for architecting and building highly available payment microservices that power millions of transactions across the continent. This role is central to our mission of providing a seamless digital payment experience for millions of users. Responsibilities: - Design and implement scalable backend services using Node.js and Go. - Integrate with major mobile money providers across Africa (M-Pesa, MTN MoMo, Airtel Money). - Lead technical architecture discussions and conduct thorough code reviews. - Optimize database queries and system performance for high concurrency. - Implement robust security practices and ensure PCI-DSS compliance. - Collaborate with product managers and frontend teams to define API contracts. - Mentor junior and mid-level developers. - Drive the adoption of cloud-native technologies and CI/CD best practices. Requirements: - 7+ years of experience in backend development. - Expert knowledge of Node.js and/or Go. - Deep experience with relational databases (PostgreSQL/MySQL) and Redis. - Proven experience with mobile money API integrations (M-Pesa G2/C2B/B2C). - Strong understanding of microservices architecture and containerization (Docker/Kubernetes). - Experience with cloud platforms like AWS or GCP. Nice-to-haves: - Experience with Kafka or RabbitMQ. - Knowledge of Elixir or other functional programming languages. - Previous experience in a high-growth fintech startup. What we offer: - Competitive salary and comprehensive health insurance. - Opportunities for continuous learning and professional growth. - A dynamic and inclusive work environment in the heart of Nairobi. - Flexible working hours and hybrid work options.