Core ObjectiveBuild an end-to-end identity resolution system that creates deterministic phone number ↔ ADID (mobile device ID) mappings using the IAB UID2 protocol and ad campaign-based matching. Project OverviewThis is a sophisticated identity resolution platform with the following workflow:Phone Numbers → UID2 Tokens → Ad Campaigns → Impression Tracking → ADID Capture → Bidirectional Mappings Key System Components: 1. Phone Upload ServiceAccepts CSV/JSON/Excel files with phone numbersNormalizes to E.164 formatEncrypts and hashes for securityTracks upload batches with validation stats 2. UID2 Conversion ServiceConverts phone numbers to UID2 advertising tokens via IAB UID2 protocolManages token refresh cycles (90-day expiration)Stores mappings in PostgreSQLAsync processing via Kafka queue 3. Ad Campaign Manager (Prebid Integration)Creates low-cost tracking campaigns targeting UID2 tokensStrategy: 1x1 pixel impressions for cost efficiencyConfigurable budget, geography, and frequency capsTracks impressions and campaign performance 4. Impression Tracking SystemCaptures ADIDs from impression eventsExtracts device data from OpenRTB bid requestsSupports both GET (pixel) and POST (S2S postback) trackingLogs user agent and geo data 5. Mapping ServiceCreates and updates phone ↔ ADID relationshipsConfidence scoring based on impression frequencyHandles multiple ADIDs per phone (multi-device users)Updates phone processing status 6. Lookup APIs (Bidirectional)Phone → ADID: Find all ADID(s) associated with a phone numberADID → Phone: Find phone number associated with ADIDRedis caching for