A few weeks ago, we were asked to review an e-commerce website that, on the surface, looked fine. Good brand, over 20,000 products, a loyal customer base built up over years. But since a "new and improved" website had gone live, something had gone badly wrong. Visitors were down. Orders were down. Sales had fallen off a cliff, and nobody inside the business could tell you exactly why.

By the time we'd finished the audit, the answer was clear. This wasn't a bad business with a bad product. It was a good business whose website had been broken by a migration that was never handled with SEO in mind, and it has been quietly bleeding money ever since. With this business that sells over 20,000 products on its website, it has been a catastrophic disaster!

It's one of the most common, and most avoidable, mistakes we see. So it's worth explaining what actually happened, because the same thing is happening to businesses up and down the country right now, often without anyone noticing until the sales figures make it impossible to ignore.

A beautiful new website isn't the same as a working one

When a business rebuilds or migrates its website, the instinct is to judge the result by how it looks. Does it feel modern? Is the branding sharp? Does it work on mobile? Those things matter, but they're not what determines whether the site actually performs.

What determines that is everything happening underneath: whether the pages that used to rank in Google still exist at the same web addresses, whether old links are correctly redirected to their new homes, whether search engines can still find, crawl and trust the site the way they used to. A web designer who understands layout and branding but not SEO can build something that looks like a huge step forward and functions as a huge step backwards, and often nobody realises until the traffic graph starts sliding.

That's exactly what we found here.

The migration was done without a redirect map

This is the single biggest issue, and it's depressingly common. When this business's old site was replaced, none of its previously-ranking pages was mapped across to their new equivalents. Product pages, category pages, and an entire section of guide content that used to rank well and convert well were simply gone, replaced with dead ends.

Every backlink pointing at those pages, every bookmark a returning customer had saved, every search result Google had built up over years, now led nowhere. That is precisely the pattern behind a sharp, sustained collapse in traffic right after a relaunch, and the longer those dead pages stay live, the more of that lost ranking becomes permanent rather than recoverable.

Decades of authority, thrown away by one redirect

It got worse. This business had an older legacy domain, the kind that's still quietly sending organic traffic and passing on real search authority years after a rebrand. That domain was supposed to redirect to the new site. Instead, it was pointing to a broken internal search results page for a single obscure product, and doing it with the wrong type of redirect, one that tells Google the move isn't permanent, so none of that accumulated authority gets passed on at all.

Decades of earned trust with search engines, gone, because the web developer did not understand SEO and nobody in the business involved in the migration understood SEO either.

Small mistakes, compounding

On top of the two big structural issues, there was a long list of smaller ones that, added together, were just as damaging:

• The site's most commercially important page was still running the template's placeholder text in its meta description and body copy — literally unedited example content, which is what Google was showing to searchers.
• An old, duplicate version of the homepage was still live, indexed, and competing with the real one.
• Checkout and account pages that should never be visible to search engines were sitting in the sitemap, inviting exactly the kind of thin-content flags that suppress rankings.
• The site's most important page was loading over 100 separate files with nothing combined or optimised, a real speed problem, and speed is a ranking factor that correlates directly with conversion.
• The brand name itself appeared in half a dozen different forms across the website and social platforms, splitting search visibility that should have been consolidated in one place.

None of this is exotic. It's the kind of thing a web developer without SEO knowledge simply doesn't know to check for, because it isn't visible in a design review; it only shows up afterwards, in falling numbers.

The user experience problems made it worse

The SEO issues were only half the story. Once a visitor did find their way in, the site itself was working against the sale: an "Add to Basket" button that failed completely silently, so customers who found what they wanted simply vanished without a trace in the analytics. Prices shown while browsing that excluded VAT and delivery, so the total jumped by well over 80% at the final step. A raw server error was visible on the checkout page at the exact moment customers were being asked for card details. Zero reviews, no trust signals, nothing to reassure a first-time buyer they were in safe hands.

Individually, each of these might cost a business a handful of sales. Together, they explain why visitors, orders and revenue can fall off a cliff within weeks of a relaunch that was meant to be an improvement.

The real lesson

The verdict on this business, once we'd been through everything, was straightforward: repair, don't rebuild. The brand was sound. The product catalogue was sound. The underlying platform was sound. What was broken was a specific, traceable list of technical and SEO failures, every one of them fixable, and every one of them avoidable in the first place with the right partner handling the new site build and migration.

That's really the point of sharing this. A website rebuild or migration is not just a design project. It's an SEO project wearing a design project's clothes. If the person building your new site doesn't understand redirects, crawl directives, indexing, technical SEO auditing and how search engines value your existing pages, you can end up with a website that looks better than the old one and performs dramatically worse, and you may not find out until the damage is already done.

What good practice actually looks like

Before any competent partner migrates or rebuilds a website, they should be doing all of the following as standard, not as an afterthought:

• Auditing every indexed page and backlink on the existing site before touching anything
• Building a complete, verified redirect map from old URLs to new ones
• Setting the correct crawl and indexing rules on pages like cart, checkout and account areas
• Testing that the core buying journey actually works, end to end, before launch
• Monitoring rankings and traffic closely in the weeks after go-live, so any issue is caught in days, not months

If you're planning a new website, or a migration to a new platform, this is the conversation to have with your web partner before a single page goes live. And if you've already been through a migration and have a feeling, even a vague one, that things haven't been the same since, it's worth having a conversation with us. The sooner a broken migration is found, the more of it can still be recovered.

Thinking about a website rebuild, or worried a past migration might be quietly costing you traffic and sales? Get in touch with Digital Optimus for a website and SEO health check before more of it is lost