01 · The Niche - VibeCraft

The idea was standing in my kitchen

My partner runs a small ceramics studio. For years I watched the same ritual: a firing finishes at 11pm, and out comes a battered A4 notebook - pages warped by water, splattered with glaze, covered in handwriting only decipherable within 48 hours of writing it. “Which ramp rate did I use for the shino?” is a question that notebook has never once answered.

The existing software answer was grim: a spreadsheet template from 2011, a Facebook group with 80,000 members trading photos of notebook pages, and two abandoned apps with 2-star reviews that all said some version of “great idea, hasn’t been updated since iOS 13.”

That combination - a painful, frequent, data-shaped problem; an audience that gathers in findable places; and competition that died of neglect rather than strength - is the exact signature of a good niche. So I wrote down what I now call the niche test, and scored Kilnfolk against it.

The niche test	What to ask	Kilnfolk’s answer
1 · Frequency	Does the problem recur weekly or more?	Potters log firings and glaze tests every session - 2–6×/week.
2 · Data shape	Is the information structured, not freeform?	Recipes (ingredients + %), firing schedules (ramps + temps), results (photos + notes).
3 · Findability	Can you reach 100 users without ads?	r/Pottery (260k), studio noticeboards, Instagram #glazechemistry, guild newsletters.
4 · Wallet check	Do they already pay for tools?	A single bag of glaze materials costs $40. Kilns cost $3,000+. Yes.
5 · Neglect gap	Are incumbents dead, not dominant?	Two apps, both unmaintained; reviews beg for updates.
6 · Witness access	Can you watch a real user use it?	I sleep next to my lead user. Unfair advantage: maximal.

Six out of six is rare. Five is enough. Below four, keep looking - the AI will happily build a beautiful app for a market that doesn’t exist, and it will not warn you.

Step one: have the AI attack the idea, not praise it

Left to its defaults, every model is a cheerleader. “What a great idea!” is the most dangerous sentence in vibe coding. So the first real prompt of the project - logged as prompt-001 - explicitly asked for hostility:

prompt-001 · the interrogation

❯ I want to build an iOS app called Kilnfolk: a glaze and firing
  journal for studio potters. Before any code, interrogate the
  idea with me. Ask the 10 hardest questions a sceptical indie
  app veteran would ask. One at a time. Be brutal. If the idea
  has a fatal flaw, I want it found tonight, not in month four.

Full transcript in my ledger. The three questions that mattered most are below.

Three of its ten questions genuinely stung:

“Why has every pottery app been abandoned within two years?” - Because they were built as generic databases with a pottery skin, by people who left the niche. My answer: stay close to the studio, ship small, and design for one workflow done perfectly rather than twenty done adequately.
“Potters skew older and analogue. Why would they adopt?” - Fair hit. This reshaped the whole product: enormous type options, one-thumb entry at the wheel, and photo-first logging (snap the test tile, tag it later).
“What’s the moat when Apple sherlocks you?” - There isn’t one, and that’s fine. Niches this size aren’t worth Apple’s time. The moat is that I answer support emails with glaze advice.

Notice what happened: the AI wasn’t the builder yet - it was the sceptical co-founder. Using it to stress-test before you use it to build is the cheapest pivot you’ll ever make. Total cost of nearly killing my own idea: eleven minutes.

Step two: talk to humans anyway

AI interrogation tells you whether the idea is logically sound. It cannot tell you whether a 63-year-old wood-firer in Devon will actually tap your buttons. So I spent two evenings in studios with a one-page questionnaire and a lot of tea. Twelve potters, same six questions. The findings rewrote the plan:

What I assumed	What the studio said	Design consequence
“They’ll type recipes in.”	11 of 12 said they’d rather photograph an existing recipe card and fix the numbers later.	Photo-first capture; OCR became a v1.1 feature instead of v1.
“Cloud sync is the headline feature.”	Nobody mentioned sync unprompted. Everyone mentioned “did it pinhole?”	Defect tracking (pinholing, crawling, running) moved to the main log screen.
“Cone 6 vs cone 10 is a settings toggle.”	Studios are organised around firing temperatures. It’s identity, not settings.	Cone/temperature became a first-class filter across the whole app.
“iPad is a nice-to-have.”	4 studios keep an iPad on a shelf as the shared studio logbook.	iPad layout promoted to launch scope - a decision that mattered in Chapter 5.

The AI can simulate a thousand users. It cannot replace one potter wiping clay on her apron before showing you her notebook.
Ledger note · 26 Feb 2026

Practice · steal this

The 48-hour niche gauntlet: (1) Score your idea against the six-row niche test. (2) Have the AI play hostile interrogator, ten questions, one at a time. (3) Talk to five real humans before you write any code. If the idea survives all three, it’s earned a spec. That’s Chapter 2.