If your site isn’t showing up in Google the way it should, the cause is often technical rather than a content problem. Pages that won’t appear in Google’s results, slow load times, broken redirects after a rebuild, or a migration that quietly tanked your traffic — these are the issues I get called in to fix.

I’m Simon McCullagh, and I run SEO Services NI from Newry. I work with businesses across Northern Ireland and the rest of the UK, and when you hire me for technical SEO, you’re working with me directly — not an account manager passing your job to someone else. I’ve spent 12 years doing this across agency, in-house and freelance roles, including owning technical SEO on client accounts through full site migrations, DNS changes and the recovery work that follows when something goes wrong.

Technical problems I fix

Technical SEO covers anything that affects whether search engines can crawl, index and understand your pages — separate from the quality of the content itself. The issues I see most often fall into a few groups:

Indexing and crawling issues — pages excluded from Google’s index, wasted crawl budget on low-value URLs, or important pages that Googlebot never reaches. I diagnose these using Google Search Console’s coverage reports alongside server log data where it’s available.
Core Web Vitals — slow loading, layout shift and poor interactivity scores that affect both user experience and ranking signals. I use Search Console, Lighthouse and PageSpeed Insights to find what’s actually causing the slowdown, rather than just reporting the score.
Redirects and redirect chains — old 301 redirects stacked on top of each other, redirect loops, or missing redirects after a URL change. Chains slow crawling and can dilute the signals search engines use to understand a page.
Canonical tag errors — canonical tags pointing at the wrong URL, or missing entirely, causing duplicate content confusion.
XML sitemaps and robots.txt — an XML sitemap tells Google which pages exist and should be crawled, so listing pages that no longer exist, or leaving out important ones, sends the wrong signal to search engines; robots.txt rules can also unintentionally block important sections of a site from crawling.
Structured data — missing or invalid schema markup that stops rich results appearing, or markup that no longer matches the visible page content.
JavaScript rendering — content that’s visible to users but not to search engines because it depends on client-side rendering that Googlebot struggles to process reliably.

Issues like these often share a root cause: a URL change after a redesign, for example, can leave old URLs in the sitemap, canonicals pointing at dead pages and a new redirect chain all at once. That’s part of why I run a full audit rather than fixing issues one at a time. I offer that as a standalone service through my SEO audit, which feeds directly into the fixes above.

Site migrations and recovery

Can a site migration hurt my rankings? Yes — a migration (domain change, platform move, URL restructure or redesign) is one of the highest-risk technical SEO events a site goes through, and it’s easy to lose rankings if redirects, canonicals or crawl access aren’t handled properly. I’ve managed full site migrations on client accounts, including DNS updates and crawl-structure changes, and I’ve also done the recovery work when a migration went wrong before I was involved.

A migration I run typically includes:

A pre-migration audit of the existing URL structure, current search visibility and organic traffic by page, so there’s a clear baseline to measure against afterwards.
A full redirect map — every old URL mapped to its new equivalent with a 301 redirect, avoiding chains and loops.
Checking canonical tags, XML sitemaps and robots.txt are updated to match the new site before launch.
Post-migration monitoring through Google Search Console, watching crawl errors and how quickly pages get reprocessed over the weeks after launch.
Recovery action if rankings or traffic dip — identifying which pages lost visibility and why, and fixing redirect or crawl gaps quickly.

As a separate example of recovery work, not migration-related, I’ve recovered traffic after a Google core update with a 27% rebound. The cause and fix for any given drop depends on what’s actually happened to that specific site, so I won’t promise a recovery outcome before I’ve looked at the data.

Platforms I work with

I work on the platforms most UK businesses actually use, rather than specialising in one stack:

WordPress — including WooCommerce for e-commerce, where product and category visibility in search results, duplicate content from variations, and plugin-generated bloat are common issues.
Shopify — working within its more restricted technical environment; for example, Shopify can generate duplicate URLs for products listed in more than one collection, so it’s worth checking how the theme handles canonical tags rather than assuming it’s sorted.
Webflow — sitemap and redirect management, plus structured data implementation, where schema types the built-in settings don’t cover may need adding through custom code embeds.
Cloudflare — DNS and caching configuration, particularly relevant during migrations where DNS changes need to be sequenced carefully to avoid downtime or crawl gaps.

If your site was built on one of these and you also need design or rebuild work alongside the technical fixes, I work alongside the web design side of the business so the two aren’t done in isolation.

How a technical SEO project works

I run projects in four stages:

Audit — a full technical crawl and review of Google Search Console data to find every crawl, speed, structured data and index coverage issue on the site.
Prioritise — ranking issues by likely impact on rankings and traffic against effort to fix. Fixing a low-impact canonical issue before a major crawl block is wasted effort, so the highest-value work goes first.
Implement — making the fixes directly, or working with your developer if changes need to go through an existing build process.
Verify — checking in Google Search Console and PageSpeed Insights that each fix has actually taken effect and that crawling and search visibility have improved, not just that the change was deployed. How long this takes depends on how quickly Google recrawls and reprocesses the changed pages.

If you want a clear view of where a site currently stands before committing to a full project, I offer a free SEO website report that flags the main technical issues.

Technical SEO FAQs

What is technical SEO?
Technical SEO is the work involved in making sure search engines can crawl, index and correctly interpret a website — covering things like site speed, redirects, canonical tags, sitemaps, robots.txt and structured data. It’s distinct from content or link-building work, though all three affect rankings together.

How do I know if my site has technical SEO problems?
Common warning signs include pages not appearing in Google despite being live, sudden traffic drops after a redesign or migration, slow load times flagged in PageSpeed Insights, or errors showing in Google Search Console’s coverage report. An audit is the reliable way to confirm what’s actually wrong, since several issues can produce similar symptoms.

Can a site migration hurt my rankings?
Yes, if redirects, canonicals or crawl access aren’t set up correctly during the move. See the migrations section above for how I manage that risk in practice — some temporary fluctuation while Google reprocesses the site is normal.

Do Core Web Vitals affect rankings?
Core Web Vitals are one of the ranking signals Google uses, alongside many others. They’re worth fixing for user experience regardless, and improvements can support rankings, but they’re rarely the sole reason a page isn’t ranking.

Fix the issues holding your site back

If you suspect technical issues are holding your site back, the quickest first step is a free SEO website report, which gives you a baseline view of crawl, speed and visibility issues. If you already know roughly what’s wrong, or you’re planning a migration and want it done properly, get in touch and we can talk through what’s needed. The same person who diagnoses the problem makes the fix.

For a broader view of how this fits with content and off-page work, see the SEO services overview.