Case study · E-commerce · Tracking & Attribution

Rebuilding the conversion tracking foundation for a scaling DTC subscription brand

When a third of Meta conversions were going invisible to the ad platform, OST rebuilt the full attribution infrastructure across browser, server, and application layers. Purchase event match quality moved from near zero to 9.3 out of 10.
Sector
E-commerce · DTC subscription
Engagement
Full-scope rebuild, converted to ongoing retainer
Scope
Server-side tracking migration, Meta Conversions API revival, subscription-aware attribution
Status
Active retainer · Expanding to sister brand
DTC Subscription Tracking Rebuild Full-scope rebuild, converted to ongoing retainer
DTC Subscription Tracking Rebuild

9.3 / 10

Purchase EMQ, up from near zero

Daily

Conversions recovered by the server pipeline

CAPI

All purchases flow through Conversions API

First-party

Tracking infrastructure owned end to end

The challenge

The Challenge

A tracking stack with three failure modes layered on top of each other.

The brand was scaling paid social on a tracking foundation that was compounding errors silently. iOS App Tracking Transparency was blocking pixel events on mobile. A server-side pipeline had been partially built by a prior vendor but never connected, and key Meta tags inside Google Tag Manager were paused. A third-party plugin was sending its own purchase events to Meta on every order, including subscription renewals, training the algorithm on the wrong audience.

The result was an attribution layer the brand could not trust. Ad dashboards did not match the backend. Match quality scores were stuck near zero. Ad budget was being optimized against the wrong signal. The stack needed to be rebuilt, not patched.

The Solution

A complete rebuild executed across browser, server, and application layers.

OST took ownership of the full tracking layer, audited every component touching event flow, and rebuilt the foundation so the brand owns its tracking infrastructure end to end. Three pieces were delivered in parallel.

A featured deliverable

01 · First-party server-side tracking infrastructure

The tracking endpoint was migrated to a custom subdomain the brand controls. Every event leaves the browser through this subdomain before reaching its destination. This sidesteps the majority of iOS pixel loss and gives the brand permanent ownership of the tracking surface.

A featured deliverable

02 · Meta Conversions API rebuilt with deduplication

The CAPI integration was rebuilt from the ground up with event-level deduplication paired against the browser pixel. Every purchase fires through both paths, Meta receives matched event IDs, and the platform counts each conversion exactly once.

A featured deliverable

03 · Subscription-aware renewal suppression

A custom component at the order layer flags subscription renewals before the page renders and intercepts them from firing as new conversions. The platform's optimization algorithm now trains on first-time acquisitions only.

The outcome

Purchase event match quality climbed from near-zero to 9.3 out of 10.

The contracted acceptance target was 9.0. The score crossed it shortly after go-live and held there.

The server pipeline systematically recovers what the browser pixel cannot see.

Wallet checkouts that bypass the browser entirely still reach Meta cleanly through the server pipeline.

Renewal noise was eliminated from the optimization signal.

The platform's algorithm now trains on first-time buyers only, which is the correct target for a subscription brand.

Engagement expanded into an ongoing infrastructure retainer.

The client moved OST onto a retained engagement covering further product rollouts and expansion to a sister brand.

Tech stack

Tech Foundation

The rebuild was anchored on three pillars:
Server-side Google Tag Manager on a custom subdomainMeta Conversions API with event-level deduplicationWooCommerce with Subscriptions, instrumented with custom order-layer logic

Is your ad dashboard not matching your backend?

OST rebuilds attribution infrastructure for DTC, subscription, and lead-gen brands where tracking is the constraint on growth.

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