About

About me.

Three years building secure, scalable products across the stack — and a Computer Science degree that keeps the theory honest.

Origin

Computer Science, Federal University of Agriculture, Abeokuta.

3+ years · Software Engineer · Mon — Fri

My name is Oriolowo Mustapha. I am a Software Engineer from Nigeria, focused on building secure, scalable systems that stay reliable, maintainable, and useful under real-world constraints.

I work across backend architecture, API design, data modeling, background-job workflows, and product-facing interfaces. My core stack includes C#, ASP.NET Core, TypeScript, Node.js, Express, React, PostgreSQL, MySQL, MongoDB, Redis, and queue-based systems like Hangfire and BullMQ. I lean on Clean Architecture, CQRS, and MediatR to keep codebases easy to reason about and easy to change.

I have shipped systems across fintech, agritech, edtech, and AI tooling, from cooperative savings and escrow payments to multi-LLM diagnostics, fact-checking, and skill-assessment platforms. I care about clear engineering decisions, dependable execution, and building software that can grow without becoming difficult to change.

Technical skills

Languages

C#
TypeScript
JavaScript (ES6+)
SQL
Python
HTML5
CSS3

Backend

ASP.NET Core Web API (.NET 8 / .NET 10)
Node.js and Express.js (v5)
Entity Framework Core (code-first migrations) and Mongoose
MediatR, FluentValidation, AutoMapper
Passport.js and Multer
REST API design, documented with Swagger/OpenAPI, NSwag, and Scalar

Architecture and patterns

Clean (Onion) Architecture, CQRS, Domain-Driven Design
Repository and Unit of Work
Transactional Outbox, idempotent transactions
Multi-tenant design, role-based access control
Webhook design
Background job processing (Hangfire, BullMQ, MassTransit, hosted workers)
LLM fallback routing, exponential backoff, circuit breakers

Databases

PostgreSQL, MongoDB, Redis, SQL Server, MySQL
Schema design, stored procedures, LINQ

Frontend

React 19, Vite, React Router v7
TanStack Query, Zustand
Tailwind CSS v4, Framer Motion, Radix UI, Lucide
React Hook Form with Zod, Axios interceptors
Responsive design and gamified, neumorphic UI

Payments and fintech

Paystack, Nomba, ALATPay, Monnify
HMAC webhook verification, virtual accounts, payouts, refunds, reversals
Ledger accounting, reconciliation, escrow flows, BVN/KYC

AI and LLM engineering

OpenAI (GPT-4o, GPT-4o-mini), Google Gemini, Groq, OpenRouter
Multimodal and vision pipelines
Structured outputs with Zod and JSON repair
Prompt design and AI-generated assessments
SerpAPI and the YouTube Data API

Code execution

Judge0 sandbox, language-specific test harnesses for 6 languages

Authentication and security

JWT with refresh-token rotation, Google OAuth 2.0, BCrypt, PBKDF2, HMAC signature verification, EXIF GPS/timestamp verification

Cloud, DevOps and testing

Azure (App Service, Virtual Machines, Application Insights), Railway, Vercel
Docker (multi-stage builds)
Git and GitHub Actions (CI, CodeQL, Dependabot, branch protection)
Serilog and Winston logging
xUnit (unit, domain, integration), Postman