.NET Architecture & System Design Interview Question #127

What is exponential backoff?

Resilience, Rate Limiting, Health Checks & Observability Senior Advanced

Quick Interview Answer

Exponential backoff increases the delay between retry attempts, reducing pressure on an unhealthy dependency. A simple sequence might wait 1 second, then 2, then 4, subject to a maximum.

Detailed Explanation

Exponential backoff increases the delay between retry attempts, reducing pressure on an unhealthy dependency. A simple sequence might wait 1 second, then 2, then 4, subject to a maximum.

Backoff is often combined with jitter so many clients do not retry at exactly the same times. Retry timing should also respect the request's overall timeout or cancellation budget.

Code Example

Attempt 1 -> fail -> wait ~1s
Attempt 2 -> fail -> wait ~2s
Attempt 3 -> fail -> wait ~4s

Stop after configured limit.