Frank Mwangi

Backend Engineer with 2+ years of hands-on experience building scalable microservices and high-availability fintech systems. Proven track record delivering USSD gateways handling 50K+ users/minute, notification systems with 99.9% uptime, and PCI DSS-compliant payment infrastructure. Core expertise in Java, Golang, Spring Boot, and AWS cloud.

Experienced with ISO 20022, MNO integrations, and event-driven architectures using Kafka. Passionate about clean, testable code that solves real business problems at scale.

Backend Engineer (Java / Golang) - Dadanada Group - Nairobi, Kenya (On-site)

(2025-01)

• Architected and delivered a USSD gateway service supporting 50K+ concurrent users/minute under high load, serving MNO partners Orange and MTN Congo.
• Built a notification system processing 1,000+ monthly SMS and email notifications with 99.9% uptime, leveraging Kafka and NATs for reliable asynchronous delivery.
• Led Java upgrade of core services from Java 17 to 21, improving performance and enabling modern language features across internal microservices.
• Integrated real-time payment flows with multiple MNOs and payment providers, contributing to ISO 20022-compliant payment switch routing.
• Supported PCI DSS compliance efforts across payment transaction workflows, collaborating with senior engineers on secure fintech architecture.
• Established robust testing framework using JUnit 5 for unit/integration tests and Testcontainers for container-based testing with PostgreSQL, Redis, and Kafka.

Full-Stack Developer - Freematrics Technologies - Eldoret, Kenya (Hybrid)

(2024-04 - 2024-10)

• Developed robust REST APIs for a sales tracking system, improving data processing efficiency by 18% and enabling seamless third-party integrations.
• Migrated the platform from a standalone system to a cloud-based SaaS model, expanding customer reach by 28%.
• Built a responsive React.js web application, resulting in a 20% increase in user engagement.
• Integrated real-time notifications and email alerts, improving system-wide communication responsiveness.
• Deployed the application on AWS EC2 with high availability, scalability, and security configurations.
• Implemented automated testing using JUnit (backend) and Selenium/Cypress (frontend), achieving high code coverage aligned with company reliability standards.

Diploma - Computer Science - Ziwa Technical Training Institute (2022-01 - 2024-01) Eldoret, Kenya