Open to a small number of projects

I build fast, well-tested web apps that keep working offline.

React and TypeScript on the front, .NET or serverless APIs behind them. For startups, small teams and founders who want software that's done properly.

baby-steps-tracker · mainCI passed

tests436 passing

engine coverage99.7%

initial JS120.8 kB / 250 kB budget

a11y checksevery route

offlinePWA, works without network

Selected work

Cart Wise shopping list, grouped by category, with items ticked off as they go in the trolley

Cart Wise · In development

A grocery price tracker and shopping-list planner for South Africa. Build a list and eventually find out where it's cheapest — one store, or a two-store split. Early development: offline-first lists and a real price catalogue work today; the recommendation engine and pamphlet scanning are next.

· Offline-first shopping lists that sync across devices
· Seeded SA grocery catalogue, searchable via SQLite FTS5

React · TypeScript · Vite · Hono · Cloudflare Workers · D1 + Drizzle · R2 · Queues · Durable Objects

Case study Code

Baby Steps Tracker dashboard showing the current baby step, key numbers, and a projected debt-free date

Baby Steps Tracker · Live

A client-side personal-finance planner built around Dave Ramsey's 7 Baby Steps — works out which step you're on, projects your debt-free date, and checks whether your goals fit your budget.

· Baby-step detection from your actual numbers
· Debt-payoff projection (snowball or avalanche)

React 19 · TypeScript · Vite 7 · Tailwind CSS 4 · Radix UI · Zustand · Zod · Cloudflare Workers

Case study Live Code

Real-Time Task Manager · Completed

A web-based real-time task management application with team collaboration built in.

· Create and manage tasks
· Attach notes to tasks

React · TypeScript · Vite · Material UI · Axios · SignalR · ASP.NET Core

Frontend Backend

What I can help with

Build your first version

An MVP, internal tool or customer portal — from a written scope to a deployed app with tests.

A written scope and fixed price before work starts
A live staging link you can check in on as it's built
Tests covering the parts that matter

Make your web app work offline

An installable PWA with offline data, sync when the connection comes back, and fast loads on slow mobile networks.

A service worker and app shell that installs like an app
Local-first data that syncs once you're back online
A bundle-size budget enforced in CI so it stays fast

Fix and speed up an existing React app

Bug fixes, performance and bundle-size work, tests added to untested code, and accessibility fixes.

A prioritised list of what's actually slow, with numbers
Tests added around the code being changed
Accessibility issues fixed, not just flagged

How I work

01
A short call, then a written scope with a fixed price per milestone.
02
Weekly progress with a working staging link, not just status updates.
03
Tests and CI from day one.
04
Handover: the code is in your repo, with a README and deploy notes.

Based in Cape Town (SAST, GMT+2). My hours overlap fully with the UK and most of Europe.

About

I'm a full-stack developer based in Cape Town, working mostly in React and .NET. I like software that's boring in the right ways — tested, documented, and easy for the next person (often future me) to pick up. Outside my day job I build and ship my own projects end to end, from the first commit to the CI gate that runs before every deploy.

Experience

Full Stack Software Developer · Advania SA
June 2024 – Present
- Lead end-to-end delivery of high-complexity features across the full stack
- Mentor new team members and provide technical coaching
- Built reusable pagination and infinite-scrolling patterns adopted across the product
Junior Developer / Software Graduate Developer · Clickatell
Feb 2023 – May 2024
- Contributed to API integrations and user-journey design
- Managed complex third-party API integrations and data mapping
- Helped reduce R&D costs through resource optimization
Intern Developer · Bull Tech Services
Jun 2022 – Jan 2023
- Worked across full project lifecycles, from requirements to delivery
- Provided technical support and maintained web content
- Built foundational skills in problem-solving and team collaboration

Education

National Diploma, Information Technology · Mangosuthu University of Technology (2022)
National Senior Certificate · Brettonwood High School (2017)

Tech

Frontend

React, TypeScript, JavaScript, HTML5, CSS3 / SCSS, Tailwind CSS

Backend

C#, ASP.NET Core, .NET, Entity Framework Core, REST APIs, Python

Data

SQL, SQL Server, PostgreSQL

Tooling

Git, GitHub, Docker, CI/CD, Azure DevOps, Microsoft Azure, Postman, Visual Studio, JIRA

AI

Claude API, AI Agents, LLM Integration, Anthropic SDK, Prompt Engineering

Writing

Building Reusable Infinite-Scroll Patterns in React

4 September 2026

A practical look at building infinite scroll with IntersectionObserver instead of scroll-event listeners — the pattern behind pagination and infinite-scrolling work on a recent project.

All posts

Let's talk

Get in touch about a project

d.langelihlekhumalo@gmail.com

I reply within one working day.