You have 90 seconds to verbally explain how you would design an expense tracking system that aggregates transactions from multiple banks like Mint or Personal Capital.
Your system should: - Connect to 1000+ banks via API (Plaid, Yodlee) - Sync transactions daily - Categorize expenses automatically (groceries, gas, etc.) - Detect duplicate transactions across accounts - Handle connection failures and re-authentication
Explain your data sync strategy, categorization, and deduplication.
How to approach it
- Hint 1
Use background jobs (cron/queue) to poll bank APIs and sync incrementally
- Hint 2
Train ML classifier on transaction descriptions to auto-categorize
- Hint 3
Deduplicate using fuzzy matching on amount, date, merchant name
Ready to answer it out loud?
Record your answer in 1:30 and Preptile scores it 1–10 with specifics — what landed, what you skipped, and what to say next time.
Practising needs an invite code. Join the waitlist and we’ll send you one.