E
Ernest Yoyowah
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Engineering Experience

Systems Built, Infrastructure Owned

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

Full-time

MTN Ghana

Jul 2023 — PresentAccra, Ghana

Software engineer at MTN Ghana since July 2023 — contributing to payment systems, the MTN Pulse youth app, and internal platforms serving millions of subscribers.

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

Certifications

Courses & Credentials

Verified certifications from recognized institutions.

Meta Front-End Developer Specialization

Meta

Sep 2023

Front-End Developer Capstone

Meta

Aug 2023

Advanced React

Coursera

Apr 2023

Principles of UX/UI Design

Meta

Aug 2023

React Basics

Meta

Mar 2023

Introduction to Mobile Development

Meta

Dec 2023

Mobile Development and JavaScript

Meta

Nov 2023

Back-End Web Development

Microsoft Imagine Cup

Jun 2023

Coding Interview Preparation

Meta

Sep 2022

Programming with JavaScript

Meta

Nov 2022

Version Control

Coursera

Nov 2022

Problem Solving Using Computational Thinking

University of Michigan

Nov 2022

Cloud Computing Basics (Cloud 101)

Coursera

Oct 2022

Technical Stack

Tools & Technologies

The technologies I work with across payment systems and software engineering.

Languages

JavaScriptTypeScriptGolang

Frontend

ReactReact NativeNext.jsTailwind CSS

Backend

Node.jsExpressMongoDBMySQL

State Management

ReduxZustand

Security

Auth0PCI DSSOWASP

Observability

OpenTelemetryProduction MonitoringTransaction State Management

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