Why we built Manifold offline-first

Manifold is an offline-first gas certificate app: you can open a property, capture a full check and finish the CP12 with no signal at all, and everything syncs the moment you're back online. We built it that way because lofts, basements and plant rooms, the places gas engineers actually work, are exactly the places with no bars.

Why does a gas certificate app need to work offline?

Because you do not get to choose where the boiler is. It lives in the loft, the cellar, the plant room, the cupboard under the stairs, and the signal in those places ranges from one bar to none. A coverage map says a postcode is fine; the meter cupboard disagrees. Any tool that needs a connection to save your work is a tool that works in theory and fails in the exact spot you need it. And coverage is not something you can schedule around, either: the job that runs long is the one in the cellar, and the day you most need the paperwork finished on site is the day with the fewest bars. So for field software, offline is not an edge case. It is the job.

What goes wrong with cloud-first field software?

Most field software assumes a connection, because it was built at a desk that had one. Hand it to someone standing in a basement and it falls over the moment the signal drops: a spinner, a lost form, a job you have to redo in the van. And trust in a tool is binary. The first time an app loses a half-finished record, you stop relying on it, go back to the pad, and type everything up later, which is the exact evening admin the software was supposed to remove. That is the quiet reason so much field software ends up unused: not missing features, but one lost job in a basement. And you cannot fix it afterwards by bolting an offline mode onto a cloud-first app, because reliable offline changes how the whole thing is built: where the data lives, how it syncs, how conflicts are resolved when two changes meet. It has to be the starting point. It is also a claim you can test in a minute: put your phone in flight mode and run a whole job. That is the test that matters, and the one a cloud-first app cannot pass.

What does offline-first mean in Manifold?

• You can open your day, a property and a job, and capture the whole check, with no connection at all.
• Nothing you enter depends on a round-trip to a server, so there is no spinner and nothing to lose when the signal drops.
• The moment you're back online, everything syncs in the background, without you pressing anything or thinking about it.
• It installs as an app on your phone, so it opens and works like one, signal or not.

What does that look like on a real job?

You arrive, open the property, and last year's appliances and record are already on the phone from the last sync, so nothing about the job depends on the bars in the basement. You do the check, capture the readings and photos where you stand, and finish the record before you pack up. Back in the van, on the drive to the next job, it all syncs on its own and the landlord's copy goes out. Nothing typed twice, nothing waiting for the evening, and at no point did you look at the signal indicator. And when a customer asks what you found last year, the answer is in your hand rather than in a cabinet at home.