Gravity and LinkedIn PostHog Conversion Routing Discovery
Reviewed the client’s Gravity and LinkedIn tracking tickets after GTM access was granted. The browser GTM container contained base pixels, Axeptio consent, attribution capture, and vendor scripts, but no real conversion logic for Qualified Sign Up or Checkout Succeeded. Platform evidence showed Meta receiving Purchase, CheckoutSuccess_PH, and QualifiedSignup_PH via Conversions API and Google Ads receiving PostHog/import-based conversion actions. The conclusion: the source-of-truth events live in PostHog/backend/server-side infrastructure, not browser GTM. The implementation path was reframed around accessing that pipeline, then routing events to Gravity through Summit’s server-side gateway and to LinkedIn through the correct conversion destination.
The GTM container was not the conversion engine; it was only the base pixel layer.
Role: MarTech auditor and tracking architect
The Problem
The client needed Qualified Sign Up and Checkout Succeeded events tracked in Gravity and LinkedIn. The client had granted GTM access, but the requested conversion events were not visible in that browser GTM container.
GTM-XXXXXXX contained mostly base pixels, consent handling, and attribution scripts, while Meta and Google Ads were already receiving Qualified Signup and Checkout Success style events via Conversions API or import-style flows. The source-of-truth conversion logic was likely in PostHog, backend code, server-side GTM, a webhook, or another integration layer.
The visible GTM container was misleading: it had the base LinkedIn Insight Tag, Meta pixel, PostHog, and Google tags, but not the real conversion event dispatch. Correct implementation required finding the existing server-side/PostHog pipeline rather than creating inaccurate browser triggers.
Approach & Architecture
Reviewed the client Asana tickets, GTM export, and Tag Assistant preview. Determined that GTM-XXXXXXX functions primarily as a base pixel/consent/attribution layer and does not contain conversion logic for Qualified Sign Up or Checkout Succeeded. Correlated this with platform evidence showing Meta receives QualifiedSignUp, Purchase, CheckoutSuccess_PH, and QualifiedSignup_PH via CAPI/multiple integrations, and Google Ads receives PostHog/import-based conversion actions. Drafted Slack and Asana messages requesting access or visibility into the actual source-of-truth event pipeline.
The browser GTM container loads PostHog, LinkedIn, Meta, Google Ads, GA4, Reddit, Intercom, Axeptio CMP, UTM Tracker, and FE Attribution Cookie Capture. Conversion events appear to be generated outside GTM, likely from PostHog/backend/server-side infrastructure, then routed to Meta CAPI and Google Ads imports. The recommended architecture is to reuse that same source pipeline to send Qualified Sign Up and Checkout Succeeded to Gravity via Summit’s server-side gateway and to LinkedIn via the appropriate server-side or conversion destination.
Key Decisions & Trade-offs
Hardest Part
Recognizing that the granted GTM access did not expose the real conversion engine and reframing the ask from 'GTM access' to 'access to the source-of-truth server-side/PostHog pipeline.'
Technical Detail
Events to map: Qualified Sign Up and Checkout Succeeded. Existing platform events include QualifiedSignUp, CheckoutSuccess_PH, and QualifiedSignup_PH.
Browser GTM, Axeptio CMP, PostHog, Meta CAPI, Google Ads import conversions, Summit server-side Gravity gateway; unknown existing source pipeline.
Reviewed GTM export version 28, Tag Assistant preview, Meta Events Manager event list, and Google Ads conversion summary.
Code
(function() { var params = ['gclid', 'fbclid', 'utm_source', 'utm_medium', 'utm_campaign', 'utm_content']; var url = new URL(window.location.href); var captured = {}; params.forEach(function(p) { var val = url.searchParams.get(p); if (val) { captured[p] = val; var d = new Date(); d.setTime(d.getTime() + 90246060*1000); document.cookie = 'fe' + p + '=' + encodeURIComponent(val) + ';expires=' + d.toUTCString() + ';path=/;domain=.client.com;SameSite=Lax;Secure'; } });
})();ChatGPT was used to inspect the GTM export, reason through platform evidence, avoid an unsafe browser implementation, and draft Slack/Asana messages requesting the exact missing server-side/PostHog access.
Measured Results
The discovery prevented an inaccurate GTM-only implementation for Gravity and LinkedIn. It reframed the client ask around access to the actual PostHog/backend/server-side pipeline where the source-of-truth events are generated.
| Metric | Value | Before | Source |
|---|---|---|---|
| GTM tags in the client container | 13 tags | n/a | GTM export |
| GTM triggers in the client container | 2 triggers | n/a | GTM export |
| GTM custom variables in the client container | 1 custom variable | n/a | GTM export |
| Meta PageView events Selected date range shown in user paste. | 340.9K | n/a | Meta Events Manager pasted data |
| Meta QualifiedSignUp events Event match quality shown as 8.0/10. | 292 | n/a | Meta Events Manager pasted data |
| Meta Purchase events Integration listed as Conversions API; event match quality shown as 8.1/10. | 243 | n/a | Meta Events Manager pasted data |
| Meta CheckoutSuccess_PH events Integration listed as Conversions API; event match quality shown as 7.9/10. | 240 | n/a | Meta Events Manager pasted data |
| Meta QualifiedSignup_PH events Integration listed as Conversions API; event match quality shown as 7.8/10. | 169 | n/a | Meta Events Manager pasted data |
| Google Ads Checkout Succeeded - Client Side Status was Needs attention; Secondary; Every; 30 days. | 53.33 conversions / 1,546.67 value | n/a | Google Ads conversion summary pasted by user |
| Google Ads Checkout Succeeded - PostHog Status was Needs attention; Primary; Every; 90 days. | 261.30 conversions / 62,286.24 value | n/a | Google Ads conversion summary pasted by user |
| Google Ads Qualified SignUp - Client Side Status was Needs attention; Primary; One; 90 days. | 94.78 conversions / 0.00 value | n/a | Google Ads conversion summary pasted by user |
| Google Ads Qualified SignUp - PostHog Status was Needs attention; Secondary; One; 90 days. | 88.33 conversions / 7,720.87 value | n/a | Google Ads conversion summary pasted by user |
| Google Ads total all conversion actions | 497.75 conversions / 71,553.77 value | n/a | Google Ads conversion summary pasted by user |
Every figure above was recorded during the work itself. Where no number was measured, none is claimed.