
Sema
A cloud call-centre for every Tanzanian business — one local number, every call captured, routed, recorded and transcribed in Swahili & English. No hardware, no IT project.
Software for founders with a vision
I build software that adds an extralayer to everyday work. Backend, web,WhatsApp commerce, dashboards, opensource: five crafts, one vision. What weship together earns a place in theworld. Let us make it useful.
I build software that adds an extra layer to everyday work. Backend, web, WhatsApp commerce, dashboards, open source: five crafts, one vision. What we ship together earns a place in the world. Let us make it useful.Start your project
A cloud call-centre for every Tanzanian business — one local number, every call captured, routed, recorded and transcribed in Swahili & English. No hardware, no IT project.

Pay strangers, get paid by strangers — safely. WhatsApp-native escrow that holds the money until both sides are happy.

Business email for Tanzania. Barua moves a business off a Gmail address onto authenticated mail on the domain it already owns — DKIM-signed, SPF and MX handled, with shared and personal mailboxes.

Session-replay for African products. Drop two lines of code, watch every session back, and fix what's broken before anyone complains.

RC-powered workshops, community races and corporate experiences — bringing technology to life for schools and families across Tanzania.

WhatsApp commerce for merchants — carts, checkout and payments where the customers already are. I own the backend.

One-click infrastructure for WhatsApp-native businesses — the rails that move orders and money end to end.

A product built for Tanpanels — shipped full-stack from first idea to production.



What does your product stand on? Not the framework, but the foundation. I start there and let everything else flow from it: the data model, the API, the queues. That way your product becomes the obvious choice.
More about thisPeople feel quality before they inspect a single line. In a load time, a transition, an empty state. Interface craft is not decoration you add later: it is how your product presents itself to the world. This is how you build something that can be yours alone.
More about thisWhatsApp is where your customers already are. Something to tap, to trust, to come back to. The work lies in details people don't always see but do feel: message timing, idempotent payments, graceful retries. This is how your brand stays in their pocket.
More about thisA dashboard is not an “oh yes, we need that too” — it must show how the business breathes. Not a template you fill in. A place where people sense whether the numbers are right or not. I build internal tools that feel familiar from the very first second.
More about thisYou ship code every day, in various repos and countless terminals. I build the scaffolds, CLIs and libraries that you reach for every day. This way your stack stays recognizable without starting from scratch every time.
More about this
I am Kelvin, and I learned my trade inside real product teams, shipping for names like Neurotech Africa and Tanpanels. I now hold the same standard from my own desk in Dar es Salaam for every founder who understands that software is more than a demo: no half measures, every decision counts.
Read my story
I don’t work for you, but with you. I ship a well-thought-out first version and take you along in the reasoning. No vague sprints here or mystery invoices there. The whole thing has to be right.

Every figure above is published on the product’s own site.

A tiny working database, built from scratch to learn what a database actually is under the hood — pages, a B-tree, a WAL.

A small stack virtual machine and bytecode interpreter — a complete little runtime, from the instruction set up.

A clean, batteries-included API scaffold I reach for to ship backends fast — auth, migrations and tests already wired.