An Important Theorem to Know for System Design Interviews
Published in
4 min readSep 2, 2022
When you place an order on Amazon, your request is probably handled by one of the distributed computer nodes based on your location.
A distributed system is one where multiple nodes operating the same business logic are distributed on different computer nodes. If one node is down, others can still process the incoming requests. This ensures the efficiency and reliability for the application.
But there is a dilemma in a distributed system, which is known as ‘CAP Theorem’.
A brief elaboration on which letter means:
- C — Consistency: “all nodes see the same data at the same time.”
- A — Availability: “reads and writes always succeed.”
- P — Partition Tolerance: “the system continues to operate despite arbitrary message loss or failure of part of the system.”
The CAP theorem states that a system can only focus on two letters.