Glossary

Blast Radius

Blast RadiusIn software delivery, a change's blast radius is the full set of components, contracts, services, and teams it can affect — directly or transitively. Measuring blast radius before merging answers 'what could this break?' so teams can size review, testing, and rollout to the real risk.

A one-line change can be trivial or catastrophic depending on what depends on it. Blast radius quantifies that: starting from the changed symbols and files, it follows the dependency and ownership graph outward to everything that could be impacted — downstream modules, shared contracts, dependent services, and the teams who own them.

Blast radius matters more in AI-native delivery because agents can produce large, wide-reaching changes quickly. A change that touches a core contract used by twelve services has a very different risk profile than an isolated leaf change, even if the diffs look similar in size.

Skaftor computes blast radius from the engineering memory graph and surfaces it on every work order and release, so reviewers and release managers can act on impact rather than diff size. It also powers the free Blast Radius Analyzer.

Frequently asked questions

How is blast radius calculated?

By traversing the dependency and ownership graph from the changed symbols outward: direct callers, transitive dependents, shared contracts/interfaces, affected services, and the owning teams. The result is a scoped set (and often a score) representing everything the change can influence.

Is blast radius the same as lines of code changed?

No. Lines changed measures the size of a diff; blast radius measures its reach. A small diff to a widely-used interface can have a large blast radius, while a large diff in an isolated module can have a small one. Reach predicts risk better than size.

See also

Related concepts

Last updated July 28, 2026 · https://skaftor.com/glossary/blast-radius