Java Developer

Architected Java-based microservices for payments and membership management using Java(Spring Boot), PostgreSQL, and MongoDB for a financial platform to support 2M+ users. Integrated mobile-money payments(M-Pesa) and implemented transaction processing queue using Kafka for high-throughput transaction processing, increasing TPS by 40%. Implemented Visa payment gateway integration on the platform, enabling seamless card payments for users. Improved critical system performance by 35% through code optimization, database indexing, and caching strategies using Redis. Setup observability stack with Prometheus and Grafana for real-time monitoring and alerting of system metrics. Managed CI/CD pipelines on Bitbucket/GCP and led API documentation with OpenAPI. Designed system architecture and data models to ensure scalability, reliability, and maintainability. Mentored a team of 2 developers in Agile practices, improving code quality and delivery timelines.

Designed and implemented smart contracts as access control on offchain medical data sharing, enabling secure and private patient data management on the Cardano blockchain. Developed REST API to integrate with Plutus smart contracts, enabling seamless interaction between off-chain applications and on-chain data. Led development of TraceLedger, a blockchain-based track-and-trace solution for coffee bean supply chain transparency with merkle root implementation for integrity proofs leading to a 80% cost reduction. Developed design specification for an on-chain lottery platform on Cardano, including smart contract architecture, transaction flow, and user interaction models. Provided technical leadership for a crypto tipping mobile application supporting multiple blockchain assets. Guided a team of five remote developers in Agile sprints, introduced code reviews and CI/CD pipelines, improving delivery schedules.

Developed BandaGo, a mobile medical application for low-resource facilities, with middleware for efficient data caching and optimization of API performance (30% improvement). Worked on the refactoring of platform middleware from Java to Go for improved performance and scalability, resulting in a 50% reduction in response times. Implemented secure REST APIs for patient data management, ensuring compliance and data integrity. Developed and maintained a custom iDempiere ERP modules for healthcare management, integrating with third party systems for patient data synchronization. Led UI redesign, enhancing user adoption, and built custom iDempiere ERP plugins for business logic customization.

Built web applications for document research management and a proposal submission system, increasing submission rates. User support and training for university staff on IT systems, security protocols, and data management best practices.