Software Developer · Founder · Chegutu, Zimbabwe

I build software that helps African businesses grow.

I'm Kelvin Johnson Liwonde, an Applied Mathematics & Computational Science graduate and the founder and developer of Marita POS, a point-of-sale system already running in shops in Zimbabwe.

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Kelvin Johnson Liwonde
● Marita POS Live in shops
BSc (Hons) 2.1 Midlands State University
1 live productMarita POS, in daily use by shops
Web + AndroidApp, server and payments, built end to end
−15% arrearsMicrofinance credit analysis at KCI
50 new clientsRecruited for KCI Shamva branch
About me

Maths, code and real businesses

I studied Applied Mathematics and Computational Science at Midlands State University and graduated with an Upper Second Class (2.1) in 2026. Alongside my studies I worked in microfinance, mining and student leadership, and saw how hard small business owners work without knowing where their money goes. So I built a solution, took it to market myself, and now support the shops that use it.

Software development

Web apps that work offline, Android apps, Python servers and databases, payment integrations and automated testing.

Data & quantitative analysis

Mathematical and statistical modelling, numerical methods and turning business data into clear reports and decisions.

Fintech & credit

Mobile-money payments (EcoCash, InnBucks via Paynow), subscription billing, and hands-on credit and risk analysis in microfinance.

Featured project
● Live in productionFounder & sole developerSep 2026 – present

Marita POS

An offline-first point-of-sale and stock system built for Zimbabwean shops, from tuckshops to multi-till supermarkets. It runs on the phone, tablet or laptop a shop already owns.

  • Sales, stock control, profit reports, customer credit, laybys and shift cash-up
  • USD, ZiG and Rand in one till; cash, EcoCash, InnBucks and swipe
  • Keeps selling with no internet and syncs several tills when back online
  • Live mobile-money payments through the Paynow gateway
  • Android app with my own Java plugin for Bluetooth, Wi-Fi and USB receipt printers
Visit maritapos.com Try the live demo
Marita POS sell screen on a computer Marita POS on an Android phone

What I built inside Marita POS

Offline sync engine

Every till saves sales locally first (IndexedDB) and syncs through a Python/SQLite server, so several tills share live stock without losing a sale when the network drops.

Mobile-money payments

Integrated the Paynow gateway for EcoCash and InnBucks prompts and automatic subscription renewal, verified with real transactions.

Android printer plugin

Wrote a native Java plugin so the Android app prints to classic-Bluetooth, Wi-Fi and USB thermal printers, with a "Find my printer" search.

Security & subscriptions

Hashed PINs, staff permissions, an audit log, per-shop keys, device limits, self-service free trials and a vendor console to run the business.

Automated testing

End-to-end tests that drive the real app in a headless browser and the Android emulator: multi-till sync, offline sales, payments, printing and deliveries.

Running it in production

Deployed on Render with a custom domain, HTTPS, uptime monitoring and weekly off-site backups with a tested restore. Diagnosed and fixed a live outage.

Kelvin setting up Marita POS with a shop owner in Harare
From code to customers

I don't just write the software. I take it to the shops.

I sell, install and support Marita POS myself: from setting up a tuckshop in Harare in person to onboarding shops remotely over WhatsApp. I also built the website, the marketing and the payment flow that turns a free trial into a paying customer.

"It has more options than the paid POS apps on the Play Store. You are putting Chegutu on the map."
Experience

Where I've worked

Sep 2026 – Present

Founder & Developer

Marita POS · Chegutu, Zimbabwe
  • Designed, built and launched the full product: web app, server, Android app and payments.
  • First clients live in Chegutu and Harare; self-service 30-day trial and $10–$20 monthly plans.
Jun 2026 – Aug 2026

General Hand, Solar Installation Project

Zimplats
  • Supported technical teams installing a large-scale solar plant under strict safety and quality standards.
Feb 2026 – Jun 2026

Sub-Warden (Residential Life Officer)

Midlands State University, Gweru
  • Responsible for the welfare and discipline of students in a hall of residence; mediated conflicts.
Aug 2024 – Jul 2025

Intern: Credit Analyst, Debt Collector & Administrator

KCI Management Consultants, Shamva Branch
  • Assessed loan applications for affordability and repayment capacity.
  • Cut arrears by 15% through collections and repayment plans, and recruited 50 new clients.
  • These results helped the branch earn performance bonuses and incentives from head office.
  • Built statistical analyses of loan performance and the monthly portfolio-quality report.
Vacation & casual work

Mining & utilities

Magaya Mine · Runtu Mine · ZESA Holdings · TelOne
  • CIP operator, mill feeder and sampler; storesman keeping stock records and reconciliations; general hand on electrical and telecom maintenance teams.

Education

2026

BSc (Hons) Applied Mathematics & Computational Science

Midlands State University · Upper Second Class (2.1)

2021

ZIMSEC Advanced Level

Pure Mathematics, Geography · Pfupajena High School

2019

ZIMSEC Ordinary Level

8 subjects, 6 at grade C or better, including Mathematics, English and Combined Science

Skills

What I work with

Software

JavaScriptHTML & CSSPythonSQL / SQLiteJava (Android)CapacitorIndexedDB & offline appsREST APIsGit & GitHubRender (cloud hosting)Payment gateways (Paynow)Automated testingAI-assisted development

Analysis & business

Mathematical modellingStatisticsNumerical methodsFinancial mathematicsExcel & Power BICredit & risk analysisStock controlProduct launchDigital marketingClient relationsLeadership
Let's work together

Hiring, partnering, or need software for your business?

I'm open to graduate and junior roles in software development, data and fintech, and to projects with businesses that want practical, reliable software.

Send an email
WhatsApp +263 71 806 9198 Call +263 78 652 6465 kelvinliwonde447@gmail.com linkedin.com/in/kelvin-liwonde maritapos.com