Marketing attribution analysis for a DTC skincare brand

Since iOS privacy changes, our blended CAC numbers stopped matching what Meta and Google report, and we are making six-figure budget decisions on gut feel. Glowary is a DTC skincare brand doing about $6M/year across paid social, search, influencer codes, and a growing email list. We have 18 months of order data, ad platform exports, and discount code usage ready to hand over. We want a rigorous independent analysis: reconcile platform-reported conversions against actual orders, build a defensible attribution view (last-touch versus a simple data-driven weighting - explain the tradeoffs to us), and quantify how much each channel actually contributes. The deliverable is a written report with channel-level CAC and a recommendation on where the next $50k/month should go, plus the Python notebooks so our team can rerun the numbers. One kickoff call, one midpoint check-in, one final walkthrough with our founders. Everything else async.