SAST vs SCA vs DAST vs IAST: Choosing the Right Scan for the Right Stage
Harness, Wednesday, September 30th, 2026
A breakdown of what SAST, SCA, DAST and IAST each find, when to run them and how to combine them across the SDLC.
Harness notes that most AppSec teams run several scan types at different pipeline stages because no single tool sees everything.
The article compares SAST, SCA, DAST and IAST: what each tests, where it fits in the software development lifecycle and how to combine them without duplicating effort or flooding developers with findings.
It starts by separating whether code is written safely from whether it uses unsafe dependencies, and maps each tool to that question.