Abdulaziz Hatamov

Small businesses on QuickBooks quietly write off overdue invoices. Not because the money is gone, but because chasing it is manual, socially awkward, and the first thing dropped when the week gets busy. The invoices that need the most persistence get the least.

A multi-tenant SaaS that connects to a company's QuickBooks over OAuth, syncs every overdue invoice, and runs a six-step sequence across email and SMS over forty-five days — escalating in tone from friendly to final notice. The first two steps are templated; the rest are written by Claude with the full engagement history as context and a hard monthly spend cap per organisation, falling back to templates once the cap is hit. Replies are classified automatically and pause the sequence. When the QuickBooks balance reaches zero, the invoice closes itself.

A supplements brand needed a storefront that could describe what it actually sells — the form, the ingredients, what each one does, who it is for, what the evidence says. Off-the-shelf platforms model a T-shirt with a size and a colour. They also needed an admin their own team could run the business from, not a developer.

Three applications in one monorepo: a Next.js storefront, a React admin panel, and a NestJS API. The catalog is modelled to the domain — products carry forms, ingredients, effects, target audiences, benefits, science references and reviews as first-class relations rather than free text. Checkout runs through Stripe with a webhook-driven order state machine. Product images upload straight from the browser to object storage over presigned URLs, so large files never touch the API server. Carts live in Redis. The admin dashboard streams revenue, month-over-month growth and a thirty-day series over WebSockets, behind role-based access enforced at the API and again at the route.

A large appliance retailer — fridges, air conditioners, gas appliances — was running branch ordering, seller payments and stock requisitions across paper and spreadsheets. Managers and field sellers needed genuinely different tools, on phones, in their own language, across multiple branches.

A cross-platform React Native application covering the operation end to end: catalog and ordering, cart and checkout, stock and inventory, requisitions, seller payments and payment types, KPI planning and tracking, vouchers, sales reporting and notifications. Fifteen service modules sit behind it. State is split between server cache and local stores so the app stays usable on a bad connection, and the whole interface is translated rather than hard-coded in one language.