Colleen Marasha — painted designer on the left, photographic engineer on the right

designer

Product thinking and interfaces that feel considered — from a magazine cover to a farmer's scan-page.

<engineer>

Offline machine learning, cryptographic systems and payment rails that keep working when the network doesn't.

91.5%
Weighted F1 — Clarion
80.7 KB
Model, distilled from 300 MB
0.837
AUC, up from 0.808
2026
BEng Hons, UZ

A little about me

Beyond the code

I'm a computer engineer who loves numbers — which is probably why I'm just as comfortable reading a balance sheet as I am dealing a hand at the card table. I was raised in a small town, and I've kept its pace with me: I like calm, I like kin, and I have little patience for destructive noise.

Away from the screen you'll find me in the garden coaxing flowers along, on the yoga mat, lost in a novel, or losing gracefully at a board game. I keep cats, quietly and happily, even though my culture side-eyes me for it. And now and then I dance with Elysium Magna — because a life of pure logic needs a little rhythm in it too.

I build things that are meant to work in the real world, for real people, often where the network is unreliable and the stakes are ordinary but important. That's the throughline between the engineering and everything else: I like making things a little calmer, a little more dependable, a little more human.

Location:
Harare, Zimbabwe
From:
A small town, at heart
Study:
BEng Computer Engineering, UZ
Loves:
Numbers, novels, flower gardens
Off the clock:
Yoga, board games, a cat or two
Also:
Dances with Elysium Magna
Colleen Marasha

Portfolio

Some of my latest work

№ 01Dissertation

Clarion

Offline AI-powered multimodal alert system that notifies deaf students of sounds they cannot hear.

  • Trained an audio event classifier to a 91.5% weighted F1-score on 3,435 validated data points, deployed on an ESP32-S3 with a React Native companion app, running fully offline with no cloud dependency.
  • Compressed a 300 MB model to 80.7 KB INT8 — a 99.97% reduction — through knowledge distillation, with quantitative analysis of the accuracy trade-off at each step.
  • Awarded a Distinction on dissertation Chapters 1–3 covering problem definition, literature review and system design.
  • Designed the multimodal alert pathway around deaf students' real constraints in Zimbabwean classrooms, where reliable connectivity cannot be assumed.
Weighted F1
91.5%
Validation set
3,435 data points
Model size
80.7 KB INT8
Compression
99.97% vs 300 MB
Hardware
ESP32-S3
Companion app
React Native
Stack
TensorFlow, Keras, TFLite
Assessment
Distinction, Ch 1–3
Supervisor
Mr G. Jekese, UZ

Experience

Where I've worked

Industrial Attachment
Zimbabwe

Software Engineering Attaché

JobSim Enterprise

  • Built the ZIMRA FDMS fiscalisation system: a Flask REST API performing multi-rate VAT reconciliation, cryptographic receipt chaining and Z-report generation against the Fiscal Device Gateway API v6.0 over mutual TLS.
  • Designed and deployed a helpdesk ticketing system that lifted attended customer claims by 95%, analysing usage data to surface recurring issues and improve service delivery.
Dec 2024 – Apr 2025
Remote

Product Management Intern

I_Train Africa

  • Translated survey and market data into learner segmentation insights that directly shaped curriculum and product decisions for digital learning platforms.
2024 – Present
Harare

IT Support Technician

Health Haven Pharmacy

  • Configured branch networks, Wi-Fi and ethernet infrastructure, and advised on hardware procurement — printers, UPS systems, cameras and workstations — for multi-branch expansion.
  • Assessed and provisioned refurbished workstations and a branch server, keeping capital spend low for a growing small business.
Nov 2023 – June 2024
R.G. Mugabe International Airport

Customer Service Agent

National Handling Services

  • Delivered passenger service in a safety-critical airport operation running to fixed departure schedules, resolving disruptions under time pressure.
May – Oct 2023
R.G. Mugabe International Airport

Aircraft Handler — Baggage Operations

National Handling Services

  • Handled aircraft turnaround and baggage operations to strict safety and timing standards.

Toolkit

Languages
PythonTypeScriptJavaScriptPHPSQL
Frameworks
FlaskLaravel 13Next.js 14React
Machine learning
LightGBMXGBoostCatBoostOptunaTensorFlowTFLite
Data & infrastructure
MySQLRedisVercelRailwayCloudflareGitHub Actions
Security
SHA-256RSA-2048ECC ECDSAMutual TLS

Education

BEng (Hons) Computer Engineering

University of Zimbabwe

Aug 2022 – Aug 2026

Final-year dissertation: Clarion — offline AI alert system for deaf students. Chapters 1–3 awarded Distinction. Supervised by Mr G. Jekese.

Certifications

Esports Management
HP / edX · 2024
Game Design
HP / edX · 2024

Try my work

Get a CV tailored to your role

Paste a job description. Every piece below is work I have actually done — the fitting selects which pieces lead and pins them in order. Nothing is written to fit; it is only fitted.

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Experience bank34 available
  • ··ClarionTrained an audio event classifier to a 91.5% weighted F1-score on 3,435 validated data points, deployed on an ESP32-S3 with a React Native companion app, running fully offline with no cloud dependency.
  • ··ClarionCompressed a 300 MB model to 80.7 KB INT8 — a 99.97% reduction — through knowledge distillation, with quantitative analysis of the accuracy trade-off at each step.
  • ··ClarionAwarded a Distinction on dissertation Chapters 1–3 covering problem definition, literature review and system design.
  • ··ClarionDesigned the multimodal alert pathway around deaf students' real constraints in Zimbabwean classrooms, where reliable connectivity cannot be assumed.
  • ··ZIMRA FDMS FiscalisationBuilt a Flask REST API integrating with the ZIMRA Fiscal Device Gateway API v6.0 over mutual TLS.
  • ··ZIMRA FDMS FiscalisationImplemented cryptographic receipt chaining using SHA-256 hashing with RSA-2048 and ECC ECDSA signatures, so any tampering with the receipt sequence is detectable.
  • ··ZIMRA FDMS FiscalisationHandled multi-rate VAT reconciliation and automated Z-report generation to meet ZIMRA's daily fiscal reporting requirements.
  • ··SmileScoreDesigning a customer loyalty scoring system for ZB Bank through the ZB Innovation Hub, from scoring model to product framing.
  • ··SmileScoreSelected as the lead exhibit for the ZB Innovation Hub Indaba showcase.
  • ··NFL Draft PredictionRaised prediction AUC from a 0.808 baseline to 0.837 through a rank-average ensemble of LightGBM, XGBoost, CatBoost and Random Forest, with Optuna hyperparameter tuning, cross-validation and feature engineering.
  • ··NFL Draft PredictionCompleted the GCI Tokyo 2026 Data Science Programme's AUC-scored competitive prediction track.
  • ··AgroLinkBuilt a hybrid ML model forecasting seed demand 6–8 weeks ahead across 60+ districts and 7 agro-ecological zones, blending planting calendars, live weather data and aggregated scan activity.
  • ··AgroLinkDesigned a three-layer anti-counterfeiting system: HMAC-SHA256-signed QR codes, per-bag serialisation supporting 99,999+ bags per lot, and GPS fraud mapping of duplicate scans.
  • ··AgroLinkDesigned a USSD and SMS fallback modelled on airtime scratch cards, so seed verification and planting guidance reach feature-phone farmers with zero data — no farmer excluded.
  • ··AgroLinkDesigned a national seed credit account system — pay at any depot, collect at any depot — with instalment tracking analogous to actuarial cash-flow and credit risk modelling.
  • ··AgroLinkSpecified a sub-5KB offline-first PWA landing page loading under 3 seconds on 2G, with Service Worker caching for zero-signal return visits.
  • ··SimAcc PortalIntegrated the Paynow Zimbabwe SDK so ratepayers can settle municipal bills by mobile money instead of queuing at council offices.
  • ··SimAcc PortalBuilt the bill enquiry flow linking council account numbers to outstanding balances.
  • ··DNC ConstructionDelivering a Next.js 14 and TypeScript frontend against a Laravel 13 API, deployed across Vercel and Railway with GitHub Actions and Cloudflare CDN.
  • ··DNC ConstructionRunning the engagement directly with the client, from requirements through to phased deployment.
  • ··FleetGuardDesigned camera-only evidence capture with GPS/time stamping and perceptual-hash duplicate detection, defeating recycled fuel-photo fraud from day one.
  • ··FleetGuardDesigned fuel-fraud detection by arithmetic rather than accusation: continuous fuel-per-kilometre reconciliation per truck exposes attendant collusion without depending on honest receipts.
  • ··FleetGuardArchitected a three-layer anti-collusion defence — account-holder verification, statistical pattern detection, and randomised audit callbacks — that moves verification away from the point of exchange.
  • ··FleetGuardBuilt the reconciliation model around a week-long cash custody window with a live cash-in-hand ledger per driver, respecting how a ~99% cash business actually operates.
  • ··Mvura ConnectSpecified a solar-assisted, SIM-connected IoT tank sensor (LTE Cat-1 with 2G fallback, US$30–45 target BOM) enabling proactive delivery calls before customers run dry.
  • ··Mvura ConnectDesigned a two-tier water quality assurance framework — potable vs utility — with geofenced source verification, chlorine photo-logging and batch traceability, turning weakly enforced regulation into a trust brand.
  • ··Mvura ConnectArchitected a two-sided marketplace on a flat connection fee rather than commission, with USSD and WhatsApp fallback so no customer segment is excluded.
  • ··Software Engineering Attaché, JobSim EnterpriseBuilt the ZIMRA FDMS fiscalisation system: a Flask REST API performing multi-rate VAT reconciliation, cryptographic receipt chaining and Z-report generation against the Fiscal Device Gateway API v6.0 over mutual TLS.
  • ··Software Engineering Attaché, JobSim EnterpriseDesigned and deployed a helpdesk ticketing system that lifted attended customer claims by 95%, analysing usage data to surface recurring issues and improve service delivery.
  • ··Product Management Intern, I_Train AfricaTranslated survey and market data into learner segmentation insights that directly shaped curriculum and product decisions for digital learning platforms.
  • ··IT Support Technician, Health Haven PharmacyConfigured branch networks, Wi-Fi and ethernet infrastructure, and advised on hardware procurement — printers, UPS systems, cameras and workstations — for multi-branch expansion.
  • ··IT Support Technician, Health Haven PharmacyAssessed and provisioned refurbished workstations and a branch server, keeping capital spend low for a growing small business.
  • ··Customer Service Agent, National Handling ServicesDelivered passenger service in a safety-critical airport operation running to fixed departure schedules, resolving disruptions under time pressure.
  • ··Aircraft Handler — Baggage Operations, National Handling ServicesHandled aircraft turnaround and baggage operations to strict safety and timing standards.