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Notes from the work
Software development, APIs, websites, AI agents, and the client requests behind them.
Reconcile an M-Pesa statement to the invoices
The phone can say paid while the invoice still says pending, and the statement can contain a payment nobody in …
LesterTechLabs Engineering · 3 min read
One checkout for M-Pesa and cards
Customers will pay by mobile money, by card, or not at all. The product should show one amount and let …
LesterTechLabs Engineering · 3 min read
Build a stock quote API
A quote API is a small contract: one symbol in, one documented price out, with the time the price was …
LesterTechLabs Engineering · 4 min read
Write the API contract before the first endpoint
An API is a promise about names, errors, and what happens when the same request arrives twice. The contract is …
LesterTechLabs Engineering · 3 min read