Available for software engineering roles

Software Engineer building secure FinTech, e-commerce and enterprise software.

I'm Kingsley Marfo, a full-stack and backend developer specialising in secure authentication, payment systems, APIs, scalable web applications and business workflow automation.

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Dunstable, United Kingdom GitHub LinkedIn

AlsoFull-Stack DeveloperBackend Engineer

Selected Work

Client work, a final-year project, and open coursework

Each card links to a full case study covering the business problem, my engineering contribution and the technologies used.

All projects

FinTech · E-commerce · Client Project

2025

Client Project

Flayona

Built the marketplace backend, payment integration, inventory model and admin workflows for a commercial e-commerce client. Designed distributor-specific pricing, variant-level stock tracking, Paystack payment flows, Mobile Money and WhatsApp notifications, and KYC-backed BNPL lending, delivered end to end under contract.

PHPMySQLPaystack APIWhatsApp Cloud API

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Enterprise · Final Year Project

2026

Final Year Project

OpFix

Built solo, end to end, as my BSc Computer Science final-year project: a secure enterprise maintenance management platform with six organisational roles, a three-tier approval workflow, and a FastAPI + PostgreSQL backend behind a React SPA. Now being prepared for future commercialisation.

FastAPIPostgreSQLReactViteSupabase

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Client · WordPress · Web

Client engagement

Client Project

Julli Jets

Built and maintain a commercial charter company's customer-facing website (private jets, helicopters and yachts) for the client on WordPress and Elementor, via a custom PHP layer that generates page layouts programmatically instead of hand-editing each one.

WordPressElementorPHPJavaScript

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Technical Expertise

Languages, frameworks and practices

Every item here is verified against production work or my CV. Nothing aspirational is listed as a current skill.

Languages

Core languages used across production and academic work.

PHPPythonJavaJavaScriptSQLHTML5CSS3

Frontend

Building responsive, installable interfaces.

ReactViteTailwind CSSResponsive web designProgressive Web AppsService workersWordPress

Backend

Services, APIs and business logic.

FastAPIREST API developmentAuthentication & authorisationSession managementBackground processingWebhook processingSMTP / transactional messaging

Databases

Relational modelling and data integrity.

MySQLPostgreSQLEntity-relationship modellingSchema designPrepared statementsDatabase migrations

APIs & Integrations

Third-party platforms integrated into production systems.

Paystack APIWhatsApp Cloud APISMS gatewaysMobile Money paymentsCard paymentsWebhooks

Security

Protecting users, data and money end to end.

Role-based access controlJWT authenticationTOTP two-factor authenticationbcrypt password hashingCSRF protectionRate limitingAccount lockoutAudit loggingHMAC-SHA512 signature verificationIdempotent payment processingOWASP-aware developmentPasswordless OTP verification

Cloud & Deployment

Shipping and operating software in production.

ApacheLinux hostingIONOS hostingHTTPS / SSL/TLS / HSTSDNS configurationSFTP deploymentScheduled background jobs

Tools & Practices

How I plan, build and ship.

Git & GitHubVS CodePostmanRequirements gatheringSoftware architectureTechnical documentationClient communicationProduction debugging

Currently learningDockerAutomated testingCI/CDAWSAzureSystem design

Professional Experience

What I'm doing right now

Full experience

Engineering

2025 – Present

Freelance Software Developer, Flayona (Client Project)

Flayona

Designed and deployed a production multi-vendor e-commerce and FinTech platform for a commercial client: distributor-specific pricing, variant-level inventory, region-based fulfilment, and a configurable Buy-Now-Pay-Later lending system, in vanilla PHP and MySQL.

Leadership

2023 – Present

Restaurant Manager

Burger King UK

Lead a team of more than 30 employees in a high-volume quick-service restaurant, alongside freelance software development and completing a BSc in Computer Science.

Open to Software Engineer roles.

I'm looking for a full-stack or backend engineering role where I can keep building secure, production software. If that's your team, I'd like to talk.

Get in touch Download CV