Replatforming without losing a sales day.

A replatform is one of the biggest bets an ecommerce business makes, and it's also where I've seen good brands lose months of momentum. The frustrating part is that it rarely goes wrong in the build, because the trouble usually starts with decisions made well before that.

Decide what you're actually fixing

"The site is slow" isn't a brief. When a team tells me they need a new platform, I want to know what's really holding them back, whether that's speed, merchandising, checkout, trade accounts or content. Rank those by how much revenue they're costing you and only then start choosing a platform, because the right answer looks very different depending on what's at the top of that list.

Protect what already works

The other half of the job is making sure you don't break what's already earning money. Map every URL that brings in traffic and redirect it, and carry over your reviews, product data and customer accounts so returning customers don't hit a wall. Pick a quiet week to launch rather than the run-up to a peak, and watch conversion every day for the first month so you catch problems while they're small.

Done well, launch day is almost dull. The gains show up in the weeks after, once the new platform starts doing the things the old one couldn't.