Google Tag Manager & Data Layer Implementation
A structured data layer built into your site, pushing clean events to GTM, and out to GA4, Meta Ads, Google Ads, and Klaviyo from a single source of truth.
Most Google Tag Manager setups are built backwards. Tags scrape the page with CSS selectors that break the next time the theme changes, events fire twice or not at all, and every platform ends up reporting a different number. I build it the other way around. First a proper data layer inside your site, where every meaningful action pushes a structured event from the code itself. GTM reads that clean event stream and forwards it to wherever it needs to go. Your marketing data becomes something you can actually trust, and adding a new platform stops meaning another round of development.
& custom builds
Proven in production
A clean data layer is the difference between marketing data you can trust and a pile of half-firing tags. On ROH Wheels I built the data layer and GTM setup that routes a single event stream to GA4, Klaviyo, and Meta Ads, so their team retargets high-intent visitors and measures spend against verified leads. At Culture Kings we built custom events feeding the ad and analytics platforms off the same idea years earlier.
What I build with Google Tag Manager
The Google Tag Manager integration work I most often take on. If yours sounds like one of these, we should talk.
A Real Data Layer, Built Into the Site
Every meaningful action pushes a structured event from your code: product viewed, add to cart, begin checkout, purchase, plus the business-specific events that matter to you. Not scraped from the DOM, not guessed at, so it survives the next theme change.
GTM as the Distribution Hub
GTM reads that one clean event stream and decides where each event goes. Add or remove a marketing platform in the container, not in the codebase, so your team keeps control without booking developer time for every change.
Fan Out to Every Platform
GA4 for analytics and attribution, Meta Ads and Google Ads for retargeting, Klaviyo for email flows, and anything else you run, all fed from the same events. One source of truth means the numbers finally agree across dashboards.
Server-side Tagging
A server-side GTM container means events are sent from your server rather than the browser, so ad blockers and iOS privacy settings stop quietly deleting your conversions. Match quality for Meta and Google improves because the data actually arrives.
Ecommerce & Custom Events
GA4's recommended ecommerce schema implemented properly, so funnels, product performance, and purchase attribution work as intended. On top of that, any signal your business cares about becomes an event and therefore a trigger for ads or email.
Consent Mode & Reliable QA
Consent Mode v2 wired in for privacy compliance, no double-firing, and everything checked in Preview mode and Tag Assistant before it goes live. A tag that fires twice is worse than one that does not fire at all, because you trust the wrong number.
A Google Tag Manager integration built to last
The same approach behind every integration I ship, from the first conversation to the years of maintenance that follow.
Scope & map
We map exactly what needs to move between Google Tag Manager and your store: orders, stock, pricing, customers, and where the awkward edge cases hide.
Build for redundancy
I build the integration around the failure modes: retries with backoff, idempotent writes, and reconciliation, so it holds up when the API has a bad day.
Test & reconcile
Tested against real data in a safe environment, with reconciliation reporting that proves Google Tag Manager and your store actually agree before go-live.
Monitor & maintain
Monitoring and alerting from launch, so failures surface immediately, and the same developer who built it is the one who keeps it running.
Google Tag Manager integration in production
Where Google Tag Manager fits in
The services and platforms a Google Tag Manager integration most often plugs into.
D2C eCommerce Web Development
Personalise your D2C website to increase conversions, revenue and order values.
Business Software Integrations
Seamlessly integrate your business software with your website, with reliable integrations that you can count on.
Shopify & Shopify Plus Development
A commercial eCommerce solution for growing digital brands.
Laravel Development
Laravel is PHP's leading framework, and I've been shipping production Laravel since version 4 in 2013.
Tracking built on a data layer, not on hope.
Anyone can drop tags into a GTM container. The reason most setups drift is that they read the page instead of the data. Selectors break, custom checkouts fire nothing, and every platform ends up with a slightly different version of the truth. The fix is upstream, in the site itself.
A typical agency
Scrapes the page and hopes it holds.
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Reads values off the page with CSS selectors, which break the next time the storefront or theme changes.
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Wires each platform its own tracking, so GA4, Meta, and email all disagree and nobody knows which is right.
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Leans entirely on browser-side pixels, so ad blockers and privacy settings silently erode conversions.
Working with me
Emits structured events from the code.
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Pushes structured events from your application code, so the data layer is a stable contract rather than a guess about the DOM.
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Feeds every platform from one event stream through GTM, so the numbers reconcile and there is a single place to fix a problem.
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Adds server-side tagging where it matters, so key conversions survive and ad platforms get the signal they need to optimise.
Other integrations
ERP & Accounting
Marketing & CRM
Shipping & Fulfilment
Common Google Tag Manager Integration Questions
What is a data layer and why does it matter?
The data layer is a structured object your site populates as things happen: a product is viewed, an item is added to cart, a quote is submitted. GTM reads from it rather than trying to scrape the page. It matters because it decouples your tracking from your markup. When the design changes, your tracking keeps working, and when you add a new marketing platform, the data it needs is already there waiting.
Can GTM send events to Klaviyo, Meta, and Google Ads at once?
Yes, and that is the whole point of doing it this way. One event, such as a purchase, gets forwarded to GA4 for reporting, Meta and Google Ads for conversion tracking and retargeting, and Klaviyo for flows, all from the same source. You are not tracking the same thing five separate times, so the numbers stay consistent and adding a sixth destination is a container change, not a development project.
Will this fix my Meta and Google ad tracking?
Usually, yes. Most broken ad tracking comes down to events blocked by ad blockers and iOS privacy settings, or conversions that simply never fire from a custom checkout. Server-side tagging sends those events from your server where they cannot be blocked, which improves match quality and recovers conversions the ad platforms were never seeing. First I audit what is actually reaching each platform, then close the gap.
Do I still need GA4 if I set up GTM?
They do different jobs. GTM is the plumbing that collects and routes events. GA4 is one of the destinations that receives them and reports on them. You use GTM to send clean, well-structured data into GA4, rather than relying on GA4's automatic tracking, which misses most of what a real store cares about. In practice you want both, with GTM feeding GA4 properly.
Can you handle Consent Mode and privacy compliance?
Yes. Consent Mode v2 is wired into the setup so tags respect the choices your visitors make, and analytics and ad platforms behave correctly whether or not consent is granted. This is not optional for stores serving customers in regions with consent requirements, and it is straightforward to get right when the data layer is built properly from the start.
My tracking numbers never match. Can that be fixed?
Almost always. Numbers disagree when events are missing, duplicated, or measured differently on each platform. With a single data layer feeding everything through GTM, there is one definition of a purchase and one place it is emitted, so the platforms downstream finally line up. I audit what is being sent today, find where it diverges, and rebuild it on a consistent event stream.