Multi-Domain User Tracking System Draft

1. Summary

Robust, privacy-compliant multi-domain user tracking system The system aims to provide comprehensive user behavior analytics across multiple domains while adhering to modern web standards and privacy regulations.

2. Problem Statement

Current tracking solutions often rely on third-party cookies, which are being phased out by major browsers. We need a solution that maintains tracking capabilities across our domains without compromising user privacy or violating emerging web standards.

3. Objectives

• Implement a first-party cookie-based tracking system across all our domains
• Ensure compliance with GDPR, CCPA, and other relevant privacy regulations
• Maintain tracking accuracy in the face of evolving browser privacy features
• Centralize data collection and analysis for comprehensive user insights

4. User Stories

• As a marketing analyst,?I want to track user journeys across multiple domains to understand cross-domain behavior.
• As a product manager,?I need accurate user engagement metrics across all our web properties.
• As a org,?I want to ensure our tracking methods are compliant with global privacy regulations.
• As a user,?I want control over my data and the ability to opt-out of tracking easily.

5. Technical Requirements

5.1 Cookie Management

• Implement first-party cookies with SameSite=Lax?attribute on all domains
• Generate and store unique user identifiers in cookies
• Set secure and HttpOnly?flags on all cookies

Technical Details:

• Use UUID v4 for generating unique user identifiers
• Set cookie max age to 1 year (31,536,000 seconds)

Code Snippet (Flask Example):

from flask import Flask, make_response, request

import uuid


app = Flask(__name__)


@app.route('/')

def set_cookie():

    user_id = request.cookies.get('user_id')

    if not user_id:

        user_id = str(uuid.uuid4())


    resp = make_response("Cookie set")

    resp.set_cookie('user_id', user_id,

                    samesite='Lax',

                    secure=True,

                    httponly=True,

                    max_age=31536000)

    return resp

        

5.2 Server-Side Tracking

• Develop a centralized tracking service to collect and process events
• Implement server-side APIs for receiving tracking data from all domains

Technical Details:

• Use FastAPI for high-performance API development
• Implement async handling for improved concurrency
• Use Pydantic for request/response modeling and validation

Code Snippet (FastAPI Example):

from fastapi import FastAPI, HTTPException

from pydantic import BaseModel

from datetime import datetime



app = FastAPI()



class TrackingEvent(BaseModel):

    user_id: str

    event_name: str

    domain: str

    timestamp: datetime

    properties: dict



@app.post("/track")

async def track_event(event: TrackingEvent):

    try:

        # Process and store the event

        await process_event(event)

        return {"status": "success"}

    except Exception as e:

        raise HTTPException(status_code=500, detail=str(e))



async def process_event(event: TrackingEvent):

    # Implement event processing logic

    pass

        

5.3 Cross-Domain Identifier Syncing

• Create a mechanism to sync user identifiers across domains
• Implement periodic syncing to maintain up-to-date user profiles

Technical Details:

• Use server-side redirects for initial sync
• Implement a background job for periodic syncing
• Use Redis for temporary storage of sync mappings

Code Snippet (Flask Example):

from flask import Flask, redirect, request

import redis



app = Flask(__name__)

r = redis.Redis(host='localhost', port=6379, db=0)



@app.route('/sync')

def sync():

    user_id = request.cookies.get('user_id')

    if not user_id:

        return "No user to sync", 400



    domains = ['domain2.com', 'domain3.com']

    next_domain = request.args.get('next', domains[0])



    if next_domain in domains:

        r.setex(f"sync:{user_id}", 300, next_domain)  # 5 minutes expiry

        return redirect(f"https://{next_domain}/receive