Engineering Decisions · Middle · Question 13 of 14
A rewritten pricing engine may fail only under real traffic. A bug would be costly, so you want to limit how many users it can reach. How do you release it?
- 1A canary: 1% of traffic, growing as metrics stay healthy
- 2A blue-green deploy switching all traffic at once
- 3A big-bang release at night, when traffic is lowest
Show the answer
Correct answer: A canary: 1% of traffic, growing as metrics stay healthy
Explanation
A canary limits the damage to a small share of users and shows real behavior before everyone is exposed. Blue-green fits fast, clean rollbacks, but every user gets the new code at the same moment. A night release fits changes that need downtime, yet low traffic may hide the very bug you're worried about.