Non-custodial crypto payment gateway — processing 47,000+ transactions across 1,200+ merchants in 45+ countries. Payment API and webhook design, multi-chain wallet integrations, and the transaction pipeline behind $8.2M+ in volume.
$ ~ whoami
Senior Full-Stack Engineer
Precious Opusunju. >
I build and ship client products end to end at Profullstack
APIs, data models, and the interfaces on top of them — with a focus on clean architecture and fast, reliable delivery. I like small, well-tested changes and fixing the awkward edge cases that show up once the happy path works.
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/ _| ___ ___(_) ___| |__ _ _
| |_ / _ \/ __| |/ __| '_ \| | | |
| _| __/ (__| | (__| | | | |_| |
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|___/ full-stack engineer
$ ~ cat ./about.md
I'm a Senior Full-Stack Engineer at Profullstack, a small senior team that ships production-grade web products for funded startups, businesses replacing bad builds, and teams that need senior-level engineering without the hand-offs.
My day-to-day is end-to-end: I design the API, model the data, and build the interfaces on top of them. That means owning a feature from schema to shipped UI, and keeping the architecture clean enough that the next feature doesn't hurt.
Across the products I've contributed to at Profullstack, I've worked on crypto payments, quantum-safe messaging, real-time collaboration, and developer tooling — for humans and for AI agents.
// portfolio.ts type Precious = { role: "Senior Full-Stack Engineer"; company: "Profullstack"; focus: "clean architecture" | "reliable delivery"; stack: "React" | "Next.js" | "APIs" | "DBs"; mobile: true; ships: true; ship(feature: string): Promise<void> { return this.ships ? deploy(feature) : Promise.reject(new Error("later")); } };
$ ~ ls ./expertise/
$ ~ cd ./work && ls -l
A few things I've been working on at Profullstack
Quantum-resistant end-to-end encrypted messaging. Real-time message sync, typing indicators and read receipts, data models, and the full-stack SvelteKit layer behind the NIST-approved post-quantum crypto.
Open-source collaborative screen sharing with simultaneous remote mouse and keyboard control — Screenhero for the modern stack. Session state, signaling plumbing, and the server-side pieces that keep multi-party WebRTC sessions reliable.
SaaS discovery directory that gives founders a free distribution channel with real SEO value. Server-rendered listings, search and filtering, category discovery, and an approval pipeline built to index well.
Real-time threat intelligence platform — threat feeds, vulnerability tracking, attack-surface monitoring, and threat-actor intelligence. Data ingestion and the APIs that surface it to dashboards and agents.
$ ~ curl --contact
Say hello
Have something interesting to build or fix? I work directly with the team at
Profullstack — no account managers, no hand-offs.
~/ send_mail.sh --to preshy
