Weaver Fintech is a purpose-driven, data-centric FinTech company revolutionizing financial services for more than 3 million South Africans. We simplify financial journeys empowering customers to shop, lend, insure, and thrive. Our Data Engineering & Analytics team plays a critical role in building scalable, modern data solutions that drive innovation and enable data-driven decision-making across the business. Join us in a collaborative, high-growth environment where your work makes a real impact.

Role Overview
As a Senior Backend Engineer, you'll help build and scale our fintech platform on AWS, owning secure, high-performance features for payments and marketplace operations that serve millions of transactions.
You'll drive architectural choices, deliver event-driven serverless systems, take end-to-end ownership of features, and mentor the team in a fast-moving, high-impact environment. If you enjoy solving complex distributed problems at real financial scale and want to make a tangible difference, this is your role.

Responsibilities

• Influence architectural decisions with focus on security, scalability, reliability, and high availability in distributed systems
• Select and implement technologies that optimize performance and cost while scaling seamlessly across PayJustNow services
• Design and deliver scalable, event-driven, serverless systems on AWS with clear API contracts between services
• Own end-to-end backend development of fraud-resistant payment features and high-throughput marketplace functionality — well-designed, maintainable, performant
• Build and maintain observability (monitoring, metrics, alerting) for full system visibility
• Work effectively across backend languages and runtimes as needed (including PHP and Python alongside Node.js/TypeScript) to support evolving service requirements
• Mentor engineers via pairing, code reviews, and technical guidance
  

Requirements

• Hands-on AWS serverless development with Lambda, API Gateway, DynamoDB, S3, EventBridge/SQS/SNS
• Strong event-driven serverless architecture on AWS using CDK (IaC)
• Proven design of resilient distributed systems in event-driven setups: idempotency, transactional outbox, eventual consistency, sagas/compensations (e.g., Step Functions, Powertools, DynamoDB transact/conditional writes) for reliable payment/marketplace flows
• Built backends handling millions of monthly transactions
• Profiling & optimizing serverless at scale: cold-start mitigation, provisioned concurrency, memory/timeout tuning, cost/latency trade-offs (Lambda Power Tuning, X-Ray, CloudWatch)
• Bonus: Laravel for integrations in production backends