Start from buy
Payroll, card processing, email delivery, tax filing, telephony and hosting are the same problem for everyone, and someone else's roadmap is doing work you would otherwise have to fund. A useful test: if you can describe what you need without a noun specific to your trade, buy it. Even custom work sits on bought parts — Stripe takes the card, Postgres holds the rows — and only the middle that nobody sells gets built.
Four signals that flip it
- Your price is a calculation. On Shopflooring, a room size resolves to boxes, square footage and a priced estimate, with waste applied before the box rollup. No general platform has a field for that.
- A noun no vendor supports. A "job" sits between CRM and accounting, and neither category wants to own it. Contractor OS exists because of that gap.
- Per-seat cost at your headcount. Subscription cost scales with people; build cost scales with scope.
- The integrations are the system. Every connector is a promise to keep up with somebody else's API.
You rarely have to decide all at once
Replace one piece at a time: leave the incumbent running, build the piece with the sharpest edge beside it, and move its work across. Atelier is that shape — it embeds with one iframe tag, and the storefront stays where it is.
The long version, with the questions to put to your own business, is in the full guide.