Tracking & Measurement Specialist Required
Budget / Salary$30–250
TypeFreelance project
LocationRemote
Posted1 hour ago
Tracking & Measurement Specialist (Server-side GTM / Stape / Meta CAPI) – Contract
About us
Java Whiskers runs cat cafés in London (White City and Marylebone) and Sweden. Tickets are sold through Roller, which is embedded in an iframe on our site. We advertise on Meta, TikTok and Google Ads, and work with Awin affiliates.
The situation
In September we launched a new UK website with a new tracking setup: a GTM web container, a server-side GTM container on Stape, Meta CAPI, TikTok Events API, GA4 and Awin. Since the launch our UK sales have dropped from +6–16% year over year to −7–14%, and our ad platforms are receiving poor-quality signals. We’ve already completed an internal audit, documented every issue and fixed the most urgent ones. We now need an experienced specialist to finish the job, verify everything end to end and make sure our data can be trusted.
What’s already been found and partly fixed
Meta received placeholder or invalid email addresses (over 50% of server events) and mismatched purchase value/currency (88% of purchases). Hashing, validation and value mapping were fixed on 6 October and need verifying.
The share of purchases tracked by the browser pixel versus the server dropped to about 30%, because the pixel didn’t fire after cookie consent. This is partly fixed for Meta, but not yet for TikTok.
Event IDs for deduplication were unstable. This is fixed and needs verifying.
What we need you to do
Verify and complete
Verify the changes already made, using GTM preview (web and server), Meta Test Events and TikTok Events Manager.
Finish the remaining fixes:
TikTok pixel firing after consent
Duplicate page_view events from SPA history changes (GA4 shows around 15 page views per session)
Correct order value sent to Awin
Splitting add_to_cart from begin_checkout, which currently fire on the same Roller step
A domain allowlist in Meta Events Manager
Bring Meta Event Match Quality above 7 for purchases.
Fix attribution
Around 50% of GA4 revenue is “Unassigned” or “Direct”. The Roller checkout iframe grants consent automatically and starts new sessions. Work with Roller support and our web developer to fix cross-domain attribution and consent handling.
Investigate an anomaly on 7 October: GA4 engagement fell to 5%, Unassigned rose to 66%, and an unusual spike of low-quality Cross-network traffic came in.
Make it compliant (UK GDPR / PECR)
Make sure the server container only forwards data to Meta, TikTok and Awin when consent has been given.
Gate click-ID cookies (gclid, fbc, ttclid, Awin) and third-party scripts behind consent.
Remove PII from GA4.
Implement Consent Mode v2 correctly across our in-house cookie banner and the Roller iframe.
Document and hand over
Write clear documentation of the final setup.
Do a short handover session with our team.
Do a follow-up check 2–4 weeks after go-live.
Must have
Proven experience with server-side GTM, preferably hosted on Stape.
Meta Conversions API and TikTok Events API, including deduplication, Event Match Quality and advanced matching.
GA4 and Consent Mode v2, with a solid understanding of how consent affects attribution.
Experience with third-party checkouts in iframes (Roller or similar booking or ticketing platforms) and cross-domain tracking.
Good knowledge of UK GDPR and PECR in a tracking context.
Methodical and well documented: you test in preview before you publish, and you explain what you changed and why.
Nice to have
Experience with Awin or other affiliate networks.
Experience with Google Ads enhanced conversions and offline conversion imports.
What you get from us
A full written audit with evidence, a step-by-step fix guide and documentation of every change made so far.
Access to GTM (web and server), Stape, GA4, Meta Business Manager, TikTok Ads and Awin.
A fast, responsive point of contact.
Scope and timeline
We expect roughly 15–25 hours for the main work, followed by a short follow-up. We’d like to start as soon as possible.
How to apply
Please send us:
A short description of a similar server-side tracking project you’ve delivered, ideally with Meta CAPI and a third-party checkout.
How you would approach the Roller iframe consent and attribution problem.
Your hourly rate or a fixed-price estimate, and your availability.
About us
Java Whiskers runs cat cafés in London (White City and Marylebone) and Sweden. Tickets are sold through Roller, which is embedded in an iframe on our site. We advertise on Meta, TikTok and Google Ads, and work with Awin affiliates.
The situation
In September we launched a new UK website with a new tracking setup: a GTM web container, a server-side GTM container on Stape, Meta CAPI, TikTok Events API, GA4 and Awin. Since the launch our UK sales have dropped from +6–16% year over year to −7–14%, and our ad platforms are receiving poor-quality signals. We’ve already completed an internal audit, documented every issue and fixed the most urgent ones. We now need an experienced specialist to finish the job, verify everything end to end and make sure our data can be trusted.
What’s already been found and partly fixed
Meta received placeholder or invalid email addresses (over 50% of server events) and mismatched purchase value/currency (88% of purchases). Hashing, validation and value mapping were fixed on 6 October and need verifying.
The share of purchases tracked by the browser pixel versus the server dropped to about 30%, because the pixel didn’t fire after cookie consent. This is partly fixed for Meta, but not yet for TikTok.
Event IDs for deduplication were unstable. This is fixed and needs verifying.
What we need you to do
Verify and complete
Verify the changes already made, using GTM preview (web and server), Meta Test Events and TikTok Events Manager.
Finish the remaining fixes:
TikTok pixel firing after consent
Duplicate page_view events from SPA history changes (GA4 shows around 15 page views per session)
Correct order value sent to Awin
Splitting add_to_cart from begin_checkout, which currently fire on the same Roller step
A domain allowlist in Meta Events Manager
Bring Meta Event Match Quality above 7 for purchases.
Fix attribution
Around 50% of GA4 revenue is “Unassigned” or “Direct”. The Roller checkout iframe grants consent automatically and starts new sessions. Work with Roller support and our web developer to fix cross-domain attribution and consent handling.
Investigate an anomaly on 7 October: GA4 engagement fell to 5%, Unassigned rose to 66%, and an unusual spike of low-quality Cross-network traffic came in.
Make it compliant (UK GDPR / PECR)
Make sure the server container only forwards data to Meta, TikTok and Awin when consent has been given.
Gate click-ID cookies (gclid, fbc, ttclid, Awin) and third-party scripts behind consent.
Remove PII from GA4.
Implement Consent Mode v2 correctly across our in-house cookie banner and the Roller iframe.
Document and hand over
Write clear documentation of the final setup.
Do a short handover session with our team.
Do a follow-up check 2–4 weeks after go-live.
Must have
Proven experience with server-side GTM, preferably hosted on Stape.
Meta Conversions API and TikTok Events API, including deduplication, Event Match Quality and advanced matching.
GA4 and Consent Mode v2, with a solid understanding of how consent affects attribution.
Experience with third-party checkouts in iframes (Roller or similar booking or ticketing platforms) and cross-domain tracking.
Good knowledge of UK GDPR and PECR in a tracking context.
Methodical and well documented: you test in preview before you publish, and you explain what you changed and why.
Nice to have
Experience with Awin or other affiliate networks.
Experience with Google Ads enhanced conversions and offline conversion imports.
What you get from us
A full written audit with evidence, a step-by-step fix guide and documentation of every change made so far.
Access to GTM (web and server), Stape, GA4, Meta Business Manager, TikTok Ads and Awin.
A fast, responsive point of contact.
Scope and timeline
We expect roughly 15–25 hours for the main work, followed by a short follow-up. We’d like to start as soon as possible.
How to apply
Please send us:
A short description of a similar server-side tracking project you’ve delivered, ideally with Meta CAPI and a third-party checkout.
How you would approach the Roller iframe consent and attribution problem.
Your hourly rate or a fixed-price estimate, and your availability.
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