Build a Self-Hosted Marketing Attribution & Lead Tracking System

The problem We run several e-commerce stores and advertise across paid social, paid search, and email. Each ad platform reports its own attributed conversions — and they all over-claim. The same sale gets counted by every platform, the numbers don't add up to reality, and we cannot honestly compare channels or decide where to put budget. There's a second, equally important gap: a meaningful share of our sales starts as a lead (an inquiry handled by a sales agent in our CRM) before it becomes an order. Today leads have no attribution at all — we don't know which channel produced a given lead, what it cost us, which agent worked it, or whether it turned into revenue. The result we want A reporting dashboard plus enriched CRM data that gives us: Every order and every lead with its true source (channel / campaign), measured by one consistent methodology across all channels — not each platform's self-reported numbers Cost per lead by channel and campaign Lead margin — the revenue a lead ultimately produced vs the marketing cost behind it Agent view — which agent took which lead, where that lead came from, and what it cost An honest side-by-side comparison of channel performance and efficiency Inside the CRM: every lead record automatically enriched with its source, so agents and management see it where they work Constraints (business, not technical) We own the result: code and configuration live on our accounts and infrastructure. We are NOT looking for setup of subscription tools like Triple Whale / Polar / Northbeam. Data refreshes automatically (daily is fine). Documented and maintainable by our team after handover. Technical approach, stack, and tooling are yours to propose — we care about the outcome. Environment Multiple Shopify stores; advertising on Meta and Google; email marketing via Klaviyo; CRM is Attio. Full admin/API access will be provided. Single decision-maker, fast answers. How to apply Briefly describe a similar system you've built Your proposed approach in a few sentences — especially how you would attribute leads and get source data into the CRM Fixed price (you may split it into phases as you see fit) and timeline Applications that don't specifically address lead attribution will not be considered.