Intuit·Software Engineer·Onsite - System Design / Architecture
- Design a system that predicts future best-sellers in a product category for a user-specified time window (anywhere from 24 hours to 90 days out), returning a ranked top-K list with low latency on high-traffic category pages.
- How would you define 'best seller' for ranking purposes: units sold, revenue, or some blended demand score? And does the business care about absolute volume or rising momentum?
- Should the ranked list be global across all users viewing a category, or personalized per user? How does that choice affect your precompute strategy?
- Walk through the write path: how do raw orders and clickstream events become model-ready features and eventually materialized forecasts?
- How do you serve a (category, window) request under 500ms p95 given tens of millions of items and bursty traffic?
- How do you handle cache invalidation and what's your fallback if the cache misses or a downstream service times out?
- How would you evaluate this system, both offline before launch and in production?
- An item goes viral at 2pm and starts selling fast. Your forecast refresh is nightly. How does your system surface it before the next batch run?
- A user requests a 90-day forecast window. Error compounds over time. How do you communicate uncertainty in the ranking, and would you cap the window?
- If you had to incorporate an LLM or agent pipeline to improve cold-start accuracy using reviews and external trend signals, exactly where in the architecture does it live, and how do you keep it off the latency-critical path?
“This one is massive.”