Products I have shipped and helped make better

The hard part

Voice calling was the part that resisted. A marketplace where two strangers have to leave the app to exchange phone numbers loses the conversation it exists to create — but building reliable calling on top of a socket layer is a much larger problem than it first appears.

The hard part

Branded merchandise is normally sold through a sales thread: an enquiry, a quote, a mockup, three rounds of email. Turning that into something a customer can complete themselves means the product configuration, the artwork upload and the pricing all have to hold together without a person in the middle.

The hard part

An SDK is judged by a standard ordinary software never faces: it runs inside someone else's product, on their release schedule, next to their code. It cannot be slow, it cannot conflict, and it cannot break when the host app is upgraded — because when it does, the customer blames the host, and the host blames you.

The hard part

A marketplace for a purchase this large is not really a listings problem. Somebody buying their first electric car has not decided yet, and the questions blocking them — will it reach my parents' house, what does it cost to run, can I finance it — are not answered by a grid of cars.

The hard part

Software for agriculture is written for people who are not at a desk, on connections that are not good, in a business with several distinct lines — supply, dairy, machinery, veterinary, testing — that share customers but almost nothing else.

The hard part

Every used-car site is the same search form, and it assumes the buyer already knows what they want. Most do not — which is why the interface here is a swipe. But a swipe carries far less information than a filter, so everything behind it has to work harder to put the right car in front of someone who has told you almost nothing.

The hard part

The people this software is for are the hardest kind to build for: outdoors, at night, alone, on a phone with a poor signal, often in a hurry. A clock-in that needs three taps and a good connection is a clock-in that does not happen, and then the roster is wrong and the payroll is wrong after it.

The hard part

A reading app is used in exactly the places with no signal. Everything the reader creates — a highlight, a note, where they stopped reading — has to be written locally and later reconciled with a backend that may have changed in the meantime, without anyone's work disappearing.

The hard part

Habit apps usually organise around the habit. This one organises around people, which changes the data model and the reminders: the unit is a relationship you are trying to maintain, not a streak you are trying not to break.

The hard part

A bidding marketplace is a harder real-time problem than an assignment one. A posted trip has to reach the right drivers immediately, several bids arrive at once and have to stay ordered and current, and the offer has to expire cleanly when the rider accepts one of them.