Frank Fontcha.

Dubai, UAE · UAE employment visa · 30 days notice

I build platforms that hold up under load.

I’m Frank Donald Kamga Fontcha, senior full stack developer · lead software engineer. For 8+ years I've led teams in Dubai, scaled systems to 500,000+ users and put distributed .NET and Node.js backends, plus applied AI/RAG, into production.

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Portrait of Frank Donald Kamga Fontcha
8+
years shipping production software
500K+
active users on a platform I re-architected
5K+
Google Play downloads for Pro E-Farmer
4
engineers led on architecture and delivery

Selected work

Products I've architected and shipped

Two products I founded, the platforms I lead at work, and a few builds that show how I approach reliability.

E-Farmer desktop dashboard: finances, livestock and weather
Product2025 — Present

Pro E-Farmer

AI-powered livestock and crop management with social commerce, on mobile, desktop and web.

NestJSPostgreSQLBullMQDjangoChromaDBGemini
6 flow write-upsView project →
MboaMeet community feedMboaMeet chats and channelsMboaMeet in-chat deal with a seller
Product2024 — Present

MboaMeet

Social and creator-commerce platform with encrypted chat, calls, lives and an HLS video feed.

React Native / ExpoASP.NET Core (.NET 10)PostgreSQLRedisSignalRHangfire
5 flow write-upsView project →

LMNTO platforms

Client / employer2022 — Present

LMNTO platforms

Bringing a 500,000-user platform in-house, plus reward engines and Web3 wallets for NodeLink, HUBLINK and HorysTech.

Node.jsNestJSNext.jsPostgreSQLMongoDBRedis
Lead Software Engineer @ LMNTOView project →

Qashio Expense Tracker

Engineering showcase2026

Qashio Expense Tracker

Production-grade finance API: transactional outbox, idempotent writes and race-safe auth.

NestJS 11TypeORMPostgreSQLRedisBullMQNext.js 15
3 flow write-upsView project →

Client / employer

HelloDocteur

Telemedicine app: patients consult licensed doctors by chat, audio or video.

View →

Client / employer

NGO incident-reporting app

White-label Flutter app for documenting incidents and supporting victims, built to work on bad networks.

View →

Proof of concept

ELEX: solar energy tokenization

A smart meter's energy readings are minted as ERC-20 tokens on BSC.

View →

Engineering blog

How the flows actually work

Write-ups of real flows from my apps: the sequence, the code, the trade-offs and what broke. Written so you can reuse the patterns.

All 17 posts →
Pro E-Farmer8 Oct 20268 min read

Variety-aware crop timelines: a farm-science engine as pure, offline TypeScript

A maize field planted with a 90-day hybrid shouldn't get the same phase dates as a 120-day local composite. Here's the small, dependency-free library behind E-Farmer's crop timelines, how it scales stages per variety and re-plans from what actually happened, and why one copy of the data beats three.

TypeScriptDomain modelingAgritechOffline-first
Qashio Expense Tracker6 Oct 20269 min read

Refresh-token rotation that doesn't log out users with five tabs open

Rotating refresh tokens on every use is good security, but a naive implementation turns parallel requests into random logouts. Here's the Redis lock, grace-replay cache and client-side single flight I use so concurrent refreshes all get the same new tokens.

AuthenticationNestJSRedisConcurrency
MboaMeet4 Oct 20266 min read

A write-behind view counter with two Lua scripts and one Postgres UPDATE

Counting video views with one UPDATE per view turns your hottest table into a lock queue. Here's how MboaMeet dedupes views in Redis with a single Lua round trip, buffers them in a hash, and flushes them to Postgres every five minutes in one statement, plus the failure mode I accepted and how I'd remove it.

RedisLuaPostgreSQLASP.NET Core
Qashio Expense Tracker2 Oct 20269 min read

Saving a transaction exactly once: idempotency keys from the form to the database

A double click, a timeout retry or two racing requests can each record the same expense twice. Here's how an Idempotency-Key that the client derives from the form, a strict server-side replay and a soft lookalike check together make 'Save' safe to press again.

IdempotencyNestJSNext.jsPostgreSQL
Qashio Expense Tracker28 Sept 20265 min read

Domain events that never get lost: a transactional outbox fanned out to BullMQ

Saving a row and publishing an event are two writes, and one of them will eventually fail. Here's the outbox → relay → one-job-per-handler pipeline I built so budget alerts fire exactly once, even through crashes and retries.

NestJSPostgreSQLBullMQEvent-driven
Pro E-Farmer24 Sept 20269 min read

Offline farm jobs and native alerts without a server: idempotent, debounced and deduped

With no backend cron in offline mode, the app itself has to age the animals, open heat windows and remind farmers to log their eggs. Here's how I run those jobs in Electron's main process and in an Expo background task, so they're safe to run any number of times and never nag twice.

ElectronExpoNotificationsBackground jobs

Toolbox

Skills & technologies

What I use in production, grouped by the problems it solves.

Backend & systems architecture

ASP.NET CoreNode.jsNestJSPHP / CakePHPDjangoFastAPIRESTGraphQLWebSocketSignalRRabbitMQBullMQHangfireMicroservicesTransactional outboxSystem design

Real-time & media

WebRTCSFUPeerJSTURN / STUNHLS streamingVoIP push (PushKit / CallKit)LiveKitClient-side encryption

Frontend & mobile

Next.jsReactReact NativeExpoIonicAngularFlutterElectronTypeScript

Data & caching

PostgreSQLMySQLMongoDBRedisSQLiteChromaDB

Cloud, DevOps & CI/CD

DockerKubernetesArgoCDGitHub ActionsBitbucket PipelinesAzure PipelinesVercelExpo EASNginxOVH / VPSGrafanaSentrySonarQube

Applied AI & ML

RAGOllamaHugging Face Transformerssentence-transformersQLoRA / LoRAPEFT

Experience

Where I've done the work

  1. Senior Full Stack Developer / Lead Software Engineer

    May 2022 — Present

    LMNTO Performance Information Technology L.L.C. · Dubai, UAE

    • Grew from Frontend Developer to Full Stack Developer to Lead Software Engineer. I now own architecture, technical planning and delivery for a team of 4 engineers.
    • Led the architecture and modernization of a flagship platform and moved it from outsourced development to fully in-house engineering, serving 500,000+ active users.
    • Re-engineered core infrastructure: tuned Docker worker clusters, indexed PostgreSQL and MongoDB, and reworked Redis caching to remove platform bottlenecks.
    • Designed asynchronous message queues that replaced brittle third-party API dependencies, improving resilience and throughput.
    • Architected reward engines, momentum challenges, and Web3 non-custodial wallet deposit and withdrawal for NodeLink, HUBLINK and HorysTech.
    • Own CI/CD and deployments across Docker, Kubernetes and ArgoCD, with uptime monitoring in Grafana and Sentry.

  2. Independent Software Consultant / Contract Developer

    Nov 2021 — May 2022

    Four and Square · Afro Holdings LTD · VMeals · UAE

    • Built cross-platform mobile gameplay interfaces with React, Ionic and Expo, and ran releases through Google Play Console tracks.
    • Delivered a full-stack real-estate portal: a headless WordPress API with Next.js and Ionic web and mobile frontends.
    • Integrated multiple payment gateways and custom checkout flows for local e-commerce businesses.

  3. Full Stack Developer / Team Lead / Analyst

    Mar 2019 — Sep 2021

    KTJC · Bafoussam, Cameroon · Remote

    • Delivered full-stack web applications and contributed to software architecture, database administration and VPS configuration.
    • Planned and coordinated development work and handled production troubleshooting.

  4. Lead Full Stack Developer / Web & Mobile

    Apr 2020 — Aug 2021

    Hello Docteur · Remote · Part-time

    • Built the medical video-consultation mobile apps (Angular, Ionic, Node.js, WebSocket, PeerJS, WebRTC, STUN/TURN) and the blog/news site.
    • Implemented real-time chat, ringing and video consultation between patients and licensed doctors.

  5. IT Web Developer

    Dec 2017 — Feb 2019

    EREC Cameroon · Bafoussam, Cameroon · Part-time

    • Built and maintained websites with CodeIgniter, HTML, CSS and jQuery, and handled network administration.

Education

Bachelor's Degree in Software Engineering

African Institute of Informatics (IAI-Cameroon)

2014 — 2017

Certifications

  • Full Stack Engineer Certificate

    Pro5.ai · Jun 2024

  • Developing ASP.NET MVC Web Applications

    Udemy · Feb 2023

Languages

  • French

    Native

  • English

    Professional working proficiency

Contact

Need a lead engineer for a platform that has to scale?

I’m in Dubai on a UAE employment visa, with 30 days’ notice. Open to senior and lead roles and to architecture consulting.

franckfontcha@gmail.com+971 55 935 8866LinkedInGitHub