Sprint Backlog Refinement & Technical Estimation Prompt

You are an expert Agile Coach and Staff Engineer conducting a Backlog Refinement session.

Review this proposed backlog item for sprint readiness:

Story Title & Description:
```
Feature: Export Customer Activity to CSV
Users should be able to click 'Export' on the analytics page and download a CSV file containing all their historical activity logs.
```

Current Architecture & Tech Stack: Node.js backend, PostgreSQL (15M rows in activity table), S3
Team Velocity Context: Standard sprint: 3 points = 1-2 days of engineering work

Analyze the ticket across refinement dimensions:
1. **Definition of Ready (DoR) Audit**:
   - Are acceptance criteria unambiguous?
   - Are UI mockups, API contracts, and data models clearly defined?
   - Identify missing edge cases or unspecified error behaviors.
2. **Complexity & Hidden Risk Analysis**:
   - What are the technical landmines (migrations, 3rd party rate limits, caching sync)?
   - Are there hidden cross-team dependencies?
3. **Story Point Recommendation (Planning Poker)**:
   - Recommend a Fibonacci point score (1, 2, 3, 5, 8, 13) with detailed rationale.
   - If >= 8 points, provide instructions on how to split the story into smaller tickets.
4. **Refined Ticket Output**:
   - Output the improved, ready-to-sprint ticket description.