Blast Radius
ELI5 — The Vibe Check
Blast radius is how much damage something can cause when it goes wrong. A bug in a low-traffic admin page? Small blast radius. A bug in the payment service during Black Friday? Nuclear blast radius. Good engineering is all about minimizing blast radius — if something WILL break (and it will), make sure it only takes down a small piece, not the whole system.
Real Talk
Blast radius refers to the scope of impact when a failure occurs. In cloud architecture, it's minimized through isolation strategies: microservices, cell-based architecture, availability zones, feature flags, and canary deployments. Blast radius analysis is a key consideration in deployment strategy, permission scoping, and change management.
When You'll Hear This
"Keep the blast radius small — deploy to 5% of users first." / "That IAM role has way too much blast radius — scope it down."
Related Terms
Availability Zone (AZ)
An Availability Zone is one of several separate data centers within a cloud region.
Canary Release
A Canary Release is when you quietly send your new code to only a tiny slice of users first — like a test audience of 1%.
Feature Flag
A Feature Flag is an on/off switch for a feature in your app, controlled without redeploying. You ship the code but keep the feature hidden behind a flag.
Incident
An incident is when something has gone wrong in production and users are affected.
Microservice
Microservices is an architecture where instead of one big app, you have many tiny apps that each do one thing.