Shift Left

Definitions

1. Moving activities (testing, security scanning, performance validation) earlier in the development lifecycle — from production leftward to development. Finding bugs in code review is cheaper than in staging, which is cheaper than in production. Shift-left security means running SAST/DAST in CI, not as a pre-release gate.

   In plain English: Catching problems earlier in development (during coding) instead of later (after deployment), when they're cheaper to fix.

   Example: "Shift security left — run secret scanning and dependency audits in the PR check, not as a quarterly pen test."

Related Terms

• Code Coverage
• Test-Driven Development
• Unit Testing
• Mutation Testing
• SAST
• DAST
• Property-Based Testing
• Acceptance Testing
• Assertion
• BDD
• End-to-End Test