Four things I can build for you.
This isn't a full-service agency list. These four are the ones RentManager is direct evidence for, because I've built and shipped every one of them in a product that's live today. If what you need doesn't fit, ask anyway. I'll tell you honestly when something is outside what I can do well right now.
SaaS product development
For a founder or business that needs the actual application built rather than a landing page. I design the data model, build the backend and its APIs, build the web frontend and, where it's warranted, the native mobile app, then wire authentication through all of them. What you get is a working system end to end, not a prototype someone else has to finish. RentManager is exactly that, and it's live.
Business workflow systems
If your operation runs on spreadsheets, WhatsApp threads and someone's memory, the workflow is real even though the software behind it isn't. I turn that into a proper system: a data model that reflects how the business actually runs, a dashboard showing the state that matters, and an audit trail so "what happened to this record" has an answer.
Backend & API engineering
Spring Boot services built around a clear domain model instead of a pile of controllers. Proper module boundaries, a schema that evolves through migrations you can read back like a history, and authorization enforced at the data-access layer instead of hidden behind a button in the UI.
Payment & third-party integrations
M-Pesa Daraja in particular: STK push, B2C payouts and callback handling, built the way a payment integration has to be. Idempotent, so a retried request can't charge or pay twice. Auditable, so every transaction traces back to whatever triggered it.
Hiring rather than contracting?
Everything on this page also describes what I'd bring to a team. I'm open to graduate and junior engineering roles and to internships, backend or full-stack, remote anywhere, on-site in Kenya, or relocating.
You'd be getting someone who has taken a system from an empty repository to a deployed product on web and mobile, who writes the tests before the interface, and who'll tell you which parts of his own work he doesn't trust yet. You'd be teaching me how software behaves under real load, and how to work well inside a codebase I didn't design. Both sides of that are written down on my skills page.
Tell me what you're trying to build.
Or what the role is. Either conversation is welcome, and WhatsApp gets the fastest reply.