Gitau Mwangi

Software Engineer with 9+ years building distributed systems across fintech, enterprise software, and social impact technology. I've designed and scaled payment infrastructure processing 50M+ monthly transactions, built platforms serving 500K+ daily beneficiaries, and delivered products from concept to production. My background includes PCI-DSS-compliant payment systems, event-driven architectures, workflow automation, and large-scale data platforms, with a focus on building software that remains reliable and maintainable long after it ships.

What I enjoy most is taking messy, real-world operational problems, whether that's payment reliability, business process automation, or field operations, and turning them into systems that quietly do their job well.

Software Engineer at Redwood Software (2025-10 – Present)

• Migrated automated batch and scheduling workflows, including Automic and Tidal integrations with SAP R3 and Bosch, to Redwood RunMyJobs, supporting a pipeline that processes 1B+ daily transactions.
• Refactored legacy job definitions into reusable, modular components using OOP design patterns, cutting configuration rework by 30% across four client migrations.
• Validated end-to-end correctness of migrated jobs against client requirements by reviewing execution logs and defect reports, with zero production-critical escapes at sign-off.
• Diagnosed and resolved migration defects escalated by field teams, tracing root causes to misconfigured jobs and dependency mapping errors, with an average fix turnaround of under 3 days.
• Onboarded new enterprise clients onto Redwood RunMyJobs, extending configurations to support reporting, sequencing, triggers, and dependency mapping with zero functional regression.
• Implemented platform features that were previously missing, including scheduler locks, file event triggers, and mail gateway integrations, closing functional gaps that had been blocking client migrations.

Software Engineer at Helapay (2025-05 – 2025-10)

• Conceived, designed, and led delivery of East Africa's first WhatsApp-powered bus ticketing platform, owning the technical architecture from initial proof of concept through to production and expanding digital booking access to 10K+ daily travellers across 15+ bus operators.
• Built and scaled a high-performance messaging platform with end-to-end WhatsApp automation workflows, designing the conversational flow and backend integrations that let travellers search routes, reserve seats, and pay, processing 50K+ payment transactions daily within chat.
• Designed and integrated a real-time notification system for booking confirmations, digital tickets, and journey reminders, cutting call centre inquiries by 35% and reducing the load on customer support teams.
• Established in-chat feedback loops and used the resulting data to prioritise iteration, driving a 20%+ increase in platform adoption and a 15%+ improvement in usability scores within a few months of launch.

Software Engineer at Food4Education (2023-10 – 2025-04)

• Designed and built a payment checkout and beneficiary verification platform for an outcomes-driven school feeding programme, architecting the integration layer between payment processors and the verification pipeline so every transaction could be traced back to a confirmed meal delivery. Processed $115K+ in monthly payments at a 98% success rate, supporting 500K+ daily learner meals.
• Built a multilingual, event-driven USSD platform with Redis-backed session management serving 450K+ parents and guardians across multiple languages, improving user experience by 25% and reducing per-session credit consumption by 1 KES, a small per-session saving that added up to meaningful cost reductions at this scale.
• Took end-to-end ownership of a mobile biometric verification system for Cisco's Tap2Eat programme, running feasibility research, designing the architecture, and coordinating delivery to replace NFC wristbands with biometric identification. Delivered one month ahead of schedule, with findings projecting 20%+ cost reduction.
• Drove a testing strategy across the engineering team that achieved 90% unit test coverage with JUnit and Mockito, materially improving code maintainability and reducing downtime for services supporting half a million learners daily.
• Integrated New Relic observability across critical services, building dashboards and alerting that gave the team proactive visibility into errors, reducing mean time to recovery (MTTR) by 10%+ and sustaining 99.9% uptime.

Software Engineer at Cellulant Group (2021-08 – 2023-09)

• Designed and built a distributed microservices platform (Java 11, Spring Boot) integrating 20+ mobile money providers across Africa, including M-Pesa, MTN Mobile Money, and Airtel Money, using event-driven architecture with RabbitMQ for asynchronous processing and reliable cross-provider messaging.
• Scaled the platform to process 50M+ monthly transactions while sustaining 99.9% uptime across 20+ African countries, applying horizontal scaling, Redis caching, and MySQL query optimization to keep latency low under peak load.
• Built and optimised key microservices for a multi-channel card payments platform, improving scalability through efficient queue management, modular design, and intelligent routing, boosting transaction success rates by 15%+ via retry mechanisms and automated notifications.
• Strengthened reliability across mobile and card networks using circuit breakers, structured retries, timeouts, and failover support, reducing payment failures by 10% while maintaining full PCI-DSS compliance throughout.
• Led the migration of legacy services to AWS, re-architecting for horizontal scalability, auto-scaling, and high availability, achieving 20% higher throughput and improved resilience under load.
• Implemented New Relic observability across the gateway, reducing incident response time by 5% and giving the team proactive visibility into reliability issues before they affected merchants.
• Acted as a technical reference point for junior engineers on the team, leading code reviews and pairing sessions focused on clean code, performance optimisation, and TDD, helping raise the team's overall test coverage and reduce regressions.
• Worked closely with product, QA, DevOps, and security teams to align the gateway's roadmap with compliance requirements and business goals across multiple markets, helping keep release cycles predictable as the provider list grew.

Software Engineer at Zimobi Limited (2017-10 – 2021-07)

• Developed credit and payment processing APIs with failover support and third-party gateway integrations, sustaining 99.9% uptime for 50,000+ users.
• Architected a USSD-based credit platform integrating internal APIs with mobile money services, expanding access for 25,000+ underserved users, improving loan approval rates by 8%, and cutting processing time from 24 hours to 15 minutes.
• Enhanced system performance through database query optimisation and Redis caching, achieving 50% faster API responses during peak transaction volumes.
• Integrated SMS gateway APIs with Safaricom and Airtel for real-time transaction alerts, boosting user engagement by 45%.
• Authored technical documentation, API references, and architectural diagrams, enabling smoother onboarding and knowledge sharing across engineering teams.

Bachelor of Science in Software Engineering – Zetech University

Diploma in Information and Communication Technology – Institute of Advanced Technology