How it works
Leave the incumbent running. Pick the piece with the sharpest edge — where the manual spreadsheet lives, or where the same record is typed twice — and build that beside it. Route that piece's work to the new system, confirm it holds, then decide whether the next piece is worth doing at all. The old system shrinks as its jobs move out.
Why not rewrite everything
A rewrite bets the business on one cutover. A piece-by-piece replacement spreads the risk and lets each step pay for itself. It also keeps the option to stop: once the painful part is gone, the rest of the old system is sometimes fine.
What it looks like in practice
Atelier is built as that kind of wedge: it embeds with one iframe tag and ingests an existing Shopify, WooCommerce or JSON catalogue, so the storefront stays where it is. On our own Growth Engine, the application kept the state and the workflow engine was demoted to a stateless task runner, rather than either replacing the other.
Where the decision gets made
Whether the existing system is worth continuing, or cheaper to replace piece by piece over eighteen months, is exactly what the free audit sets out to answer — including when the answer is not the one that bills more.