Circle Software Engineer System Design Interview Questions
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Design banking payment scheduling system
System Design: Banking Payment System Enhancements Context You are building a minimal bank-transfer payment orchestration service (e.g., ACH/SEPA) tha...
Design in-memory DB with TTL and backup
Design a Versioned In-Memory Key → (Field → Value) Store with TTL, History, and Backup/Restore You are building an in-memory database that stores valu...
Design an in-memory KV DB with TTL, scans, backup
In-Memory Key→Hash Database: Design and Implementation Context Build a single-process, in-memory data store that supports a Redis-like hash model with...
Trace and reduce redundant curl requests
Instrument and Optimize Client HTTP Requests for a Workflow Context You have a client that performs a defined workflow against an HTTP API (for exampl...
Design flight-price search service
System Design: Cheapest Flight Search Across Multiple Providers Context Design a backend system that searches multiple flight providers (airlines, OTA...