Sean Dinwiddie technical articles — page 3

Module 3 of the community course: functional reactive programming, event streams and building responsive interfaces from them.

A starting point for functional reactive programming: the core ideas, the vocabulary and what it is actually good for.

Event streams and reactive programming, two core ideas of functional reactive programming, and how they make asynchronous data something you can reason about.

The core concepts you need before functional reactive programming becomes useful rather than merely clever.

How functional reactive programming changes the feel of an interface, and why declarative event handling makes responsiveness easier to keep.

How to apply functional reactive programming to individual software modules, and what changes about their inputs, state and testing when you do.

The API behind a custom app: a Haskell Servant type that states every route, thin handlers and each shop's data kept apart in Nile's Postgres.

How a Gherkin scenario becomes a Redux Toolkit slice: the Given sets the state, the When dispatches one event, and each Then reads a selector.

Where the client meets the API: one RTK Query root per base URL, generated endpoints reviewed, tags that refetch and every response decoded.

The view that places the order: view-model selectors shape what it shows, the hooks stay thin, and its test reads the screen the way the customer does.

One feature from written scope to launch: its stories and stack, a declined card through the API, endpoint, slice and view, and the review against the scope.

Module 5 of the community course: an agent at work on a business process, with typed tools, a skill it loads and a person approving what leaves the building.

Module 5 as a twenty-minute meetup talk: the agent loop, skills, a person approving what leaves, email as data, evals on real days and handover.

An agent is a model in a loop with tools: typed tool contracts, stopping conditions as typed outcomes, and a scripted model so tests never call a real one.

An agentic skill is a folder with a SKILL.md: a description that triggers on the right tasks, instructions from a user story, and evals for every change.

One order typed into three systems, automated end to end: a person approves each order before it's entered, and an email's text is data, never instructions.