Lead Frontend Engineer · MTN Ghana

Ernest Yoyowah

Software Engineer — Payments & Systems

Building secure payment infrastructure and transaction systems at MTN Ghana — Mobile Money, PCI DSS–compliant card flows, and backend services at scale.

ReactTypeScriptNode.jsGolangNext.js

View Work View Projects

Accra, Ghana

Engineering Experience

Systems Built, Infrastructure Owned

A record of systems engineered, infrastructure scaled, and financial flows secured.

Full-timeCurrent

MTN Ghana

Jul 2023 — PresentAccra, Ghana

CurrentMTN Pay & Self Service Portal

Lead Frontend Engineer

Mar 2025 — Present

Leading frontend on MTN Pay and the Self Service Portal — MTN's payment gateway and self-service platform for broadband, bundles, SIM, and eSIM management.

Built secure payment flows for Mobile Money, PCI DSS-compliant Mastercard checkout, and airtime across broadband and digital services
Engineered end-to-end transaction flows — MSISDN input, OTP verification, async status handling — with resilient retry and duplicate-submission logic
Implemented SIM swap validation and Ghana Card (NIA) identity verification for high-risk operations
Enforced OWASP-aligned security across all flows: input sanitisation, secure token handling, no hardcoded secrets, safe redirects
Collaborated with DevSecOps on Fortify scans; trusted as go-to engineer for critical production escalations

ReactTypeScriptNode.jsGolangMTN PayMTN SSPAirtime & Bundle PaymentsMastercardPCI DSS

MTN Pulse Team

Software Engineer

Jul 2023 — Feb 2025

Software engineer on the MTN Pulse team — MTN's youth platform within the MyMTN app, serving 100,000+ active users.

Identified 15+ codebase inefficiencies and executed a migration plan that reduced technical debt by 40%
Built a Golang API proxy serving realtime streaming analytics across multiple MTN apps
Built backend services in Node.js and MongoDB; contributed payment integration flows (Mobile Money, airtime) to the Pulse app
Contributed to Agile delivery — sprint planning, feature demos, and iterative feedback loops

ReactTypeScriptNode.jsMongoDBGolangMTN PulseMyMTN App

Full-time

Software Engineer

Jadaad Technologies

Jun 2024 — Nov 2024Kumasi, Ghana

Contributed to the development of Hygeieiora and Jadaad web applications, improving performance, responsiveness, and cross-device usability.

Built and maintained reusable frontend components using React, TypeScript, Material-UI, and Tailwind
Implemented user-facing features including blog functionality and real-time call alerts
Integrated backend APIs using Node.js and MongoDB
Collaborated closely with designers to deliver user-centric interfaces aligned with product requirements
Managed tasks and delivery using ClickUp, ensuring timely execution of features and updates

ReactTypeScriptTailwind CSSMaterial-UINode.jsMongoDBHealthcareWeb Applications

Full-time

Agile Developer

Xcelsz

Jun 2023 — Aug 2023Ghana

Collaborated with a cross-functional team to improve mobile responsiveness across web products, delivering a seamless user experience across devices.

Collaborated with cross-functional team to achieve project objectives and meet sprint goals
Implemented solutions for enhancing mobile responsiveness — responsive navigation, adaptive header and hero section, optimised content layout, and responsive media
Analysed the current home page for mobile responsiveness and identified areas for improvement
Utilised CSS media queries and responsive design techniques to create a seamless experience across mobile devices
Tested and refined mobile responsiveness, incorporating user feedback and ensuring alignment with brand guidelines

ReactCSSGitWebMobile Responsiveness

Full-time

Software Developer

DMI

Sep 2020 — Nov 2021Ghana

Led the development of Dkeys Music Institute's official website, focusing on modern UI/UX, responsive design, and SEO optimisation.

Led the development and design of the official website, focusing on modern UI/UX principles
Implemented responsive design for optimal performance across various devices
Enhanced website visibility and search engine rankings through effective SEO optimisation strategies
Collaborated with stakeholders to align project solutions with business goals
Leveraged ReactJS, HTML5, and CSS3, integrating third-party libraries for advanced functionality
Integrated social media and Open Graph Meta Tags to strengthen online brand presence

ReactHTML5CSS3WebSEO

Full experience & certifications

Fintech Systems

Payment Infrastructure Expertise

Deep experience building the critical systems that move money — securely, reliably, and at scale in telecom and digital commerce environments.

Transaction Flow

Client App→

API Gateway→

Payment Engine→

MoMo / Card

Mobile Money Infrastructure

End-to-end Mobile Money transaction flows including disbursements, collections, and wallet reconciliation.

MoMo APIUSSDDisbursements

Card Payment Systems

PCI DSS–compliant Mastercard hosted checkout integrations with tokenization and secure data handling.

PCI DSSMastercardTokenization

Airtime & Digital Goods

Airtime recharge pipelines with retry logic, idempotency keys, and carrier gateway integrations.

Airtime APIIdempotencyRetry Logic

OTP & Fraud Prevention

Multi-channel OTP verification and fraud prevention — SIM swap validation and Ghana Card (NIA) integration.

OTPSIM SwapNIA Integration

Transaction Observability

Real-time monitoring and alerting for payment infrastructure health using OpenTelemetry and Panorama.

OpenTelemetryPanoramaMonitoring

Resilient Architecture

Transaction flows built for graceful degradation — retries, duplicate submission handling, and async status updates.

Retry LogicIdempotencyAsync Polling

Featured Projects

Systems I've Engineered

Production systems and active tools — payment infrastructure, telecom platforms, and fleet intelligence.

FintechProduction

MTN Pay

Central Payment Gateway

MTN's central payment gateway used across multiple MTN services and apps — Mobile Money, Mastercard hosted checkout, and airtime.

ReactTypeScriptNode.jsGolang

TelecomProduction

MTN Self Service Portal

Customer Self-Service Platform

Customer portal enabling MTN subscribers to manage products and services — broadband, bundles, SIM, eSIM — without visiting a retail shop.

ReactTypeScriptNode.js

TelecomProduction

MTN Pulse

Youth Platform · MyMTN App

Contributed to the MTN Pulse experience within the MyMTN app — MTN's youth-focused platform for offers and data bundles.

ReactTypeScriptNode.js

Identity & SecurityProduction

MTN Auth Services

Centralized Identity & Access

Auth0-based centralized authentication service consumed by multiple MTN applications in Ghana and South Africa.

Auth0Node.jsTypeScript

SystemsProduction

Autosurveil GPS

Fleet Intelligence Platform

Full-stack GPS fleet tracking platform with real-time vehicle monitoring, route analytics, and authentication flows.

Next.jsTypeScriptNode.jsMongoDB

View all projects

Writing

Engineering Notebook

Thinking in public about payment systems, reliability engineering, and the craft of building software.

Fintech Engineering8 min read

Transaction Orchestration in High-Volume Payment Systems

How to design resilient transaction pipelines that handle failure gracefully — from idempotency keys to dead letter queues.

PaymentsArchitectureReliability

Coming Soon

Security6 min read

PCI DSS Compliance for Frontend Engineers

What frontend engineers building card payment flows actually need to know about PCI DSS, tokenization, and hosted checkout.

PCI DSSSecurityReact

Coming Soon

Reliability Engineering7 min read

Observability for Payment Systems

Building dashboards, alerts, and distributed tracing for payment infrastructure — what to measure and why it matters.

ObservabilityPaymentsSRE

Coming Soon

Articles in progress — building in public

Read all articles

Contact

Let's build something meaningful.

Whether you're building payment infrastructure, scaling backend systems, or want to talk engineering — I'm open to interesting conversations.

Accra, Ghana

GitHub

@Ernest-Yoyowah

Ernest Yoyowah

ernestniiyoyowah@gmail.com

Send a message