Harrison Onyango Aloo
Backend Software Engineer — Node.js · Python · Payment Integrations
I build backend systems that move money. Four production platforms serving Kenyan businesses — WhatsApp commerce, fleet management, welfare payments.
About Me
Who I Am
I build backend systems that move money. In the past year I've shipped three production platforms for Kenyan businesses — a multi-tenant WhatsApp commerce SaaS with usage-based M-Pesa billing, a welfare-management system handling member contributions, claims and agent commissions, and a mobile job marketplace for the fishing industry — and contributed to a fleet-management platform at Taquana. My work centres on REST API design, PostgreSQL and MySQL schema design, JWT and role-based access control, and the callback verification, idempotency and reconciliation that payment integrations actually demand.
Education
Certificate of Completion (Artificial Intelligence)
Artificial Intelligence
Moringa School
2025 – 2025
Part-time program in applied AI: machine learning fundamentals, model training and evaluation, and building LLM-backed applications.
Bachelor of Science
Software Engineering
University of Eastern Africa, Baraton
2021 – 2025
Second Class Upper Division. Core coursework in data structures and algorithms, database systems, software architecture, and distributed systems.
Technical Skills
23 technologies across 4 domains
Frontend
Backend
Database
Tools & DevOps
Featured Projects
Here are some of my recent projects that showcase my skills and expertise
Imara Logic
A multi-tenant SaaS platform that lets African businesses run their entire sales funnel inside WhatsApp — from first message to paid order. Built by a team of five; as one of two core engineers I owned the tenant isolation layer, the usage-based billing engine with M-Pesa integration, and the React dashboard. In production with paying customers.
FishCrewConnect
A full-stack platform connecting boat owners with fishermen — featuring job postings, CV-based applications, real-time messaging via Socket.IO, and a web admin panel. Ships as a React Native mobile app, Node.js API, and React admin dashboard.
Shena Companion Welfare Association
A full-stack welfare management platform for a Kenyan funeral benefit association. Handles member registration, M-Pesa payment processing, claims submission, agent commissions, and bulk SMS/email campaigns — built with a custom PHP MVC framework and MySQL.
ENIGMA APEX
A professional prop-firm trading assistant — "training wheels for prop traders". Monitors real-time compliance for Apex, FTMO, TopStep, and MyFundedFX, reads AlgoBox signals via OCR, applies Kelly Criterion position sizing, and delivers AI first-principles guidance across a 6-chart Streamlit dashboard.
Nganyaapp—Fleet Management & Booking Platform
Nganyaapp is an all-in-one fleet management, booking, and tracking platform designed for modern transport companies. I contributed to the development of core features during my internship, focusing on system functionality, performance, and usability.
Experience & Education
Professional Experience
Freelance Full-Stack Developer
Self-Employed
Responsibilities: • Designed and developed responsive websites for businesses and individuals. • Built full-stack web applications using React, Next.js, Node.js, Express, and Supabase. • Integrated third-party APIs such as payment gateways, authentication, email services, and AI APIs. • Optimized website performance, SEO, and accessibility. • Deployed applications to Vercel and managed databases with PostgreSQL/Supabase. • Maintained client websites and implemented new features based on feedback. Key Achievements: • Delivered multiple client projects from design through deployment. • Improved website performance and user experience. • Worked directly with clients to gather requirements and provide technical solutions.
Backend Engineer
Imara Logic
Contributing engineer on a five-person team building a multi-tenant conversational commerce SaaS — WhatsApp as a full sales channel for African businesses. One of two core engineers; ~166k LOC, 612 route handlers, 144 tables, 551 of 1,332 commits mine. In production with paying customers. Still contributing as new work comes up. Responsibilities: • Built the multi-tenant isolation layer — every query scoped to a tenant, with a WhatsApp tenancy binding mapping each inbound Meta phone-number ID to exactly one tenant, and guards preventing cross-tenant sends, covered by regression tests. • Designed a usage-based billing engine on the M-Pesa Daraja API: idempotent charges, a pending-to-paid state machine, webhook resolution, and a reconciler that sweeps payments stranded when a callback never arrives. • Built declarative Express middleware metering every outbound message and enforcing contact, seat, channel and feature limits, with a single plan-config module as the source of truth for prices and limits. • Implemented in-thread commerce over the WhatsApp Cloud API — catalog, cart, checkout, delivery-zone pricing and receipts — with a graceful degradation chain across interactive, plain-text and approved-template messages. • Built the React and TypeScript operator dashboard: virtualized multi-channel inbox, CRM pipeline, campaign composer, analytics and billing. Key Achievements: • Shipped to production with paying customers, billing in local currency over M-Pesa. • Made month-end billing reconciliation fault-isolated per tenant, so one failed charge cannot block the rest. • Hardened delivery: multi-stage Docker builds with a non-root runtime, plus pre-commit and CI secret scanning.
Software Engineer
Taquana LTD
NGANYAAPP - Developed comprehensive fleet management platform with GPS tracking, booking systems, and staff management. Built responsive web interfaces, integrated real-time tracking APIs, and implemented automated scheduling features for transport companies.
Education
Certificate of Completion (Artificial Intelligence)
Moringa School
Field: Artificial Intelligence
Part-time program in applied AI: machine learning fundamentals, model training and evaluation, and building LLM-backed applications.
Bachelor of Science
University of Eastern Africa, Baraton
Field: Software Engineering
Second Class Upper Division. Core coursework in data structures and algorithms, database systems, software architecture, and distributed systems.
Get In Touch
Have a project in mind or want to collaborate? Feel free to reach out!
Location
Nairobi, Kenya
Let's Connect
I'm always open to discussing new projects, creative ideas, or opportunities to be part of your visions. Whether you have a question or just want to say hi, I'll try my best to get back to you!