DentSignal engineering case study · CI/CD

Eleven red checks were not one bug.

The pipeline looked like one large failure. In reality, code style, handler wiring, browser rules, security scans, dependencies, and frontend test doubles had separate causes.

Area: Python, TypeScript, security and supply chain
Evidence: Historical PR-reported validation
Boundary: Eleven gates at one cited revision

Plain English

A red pipeline needs a map.

What broke
Eleven checks failed across unrelated parts of the product, hiding which change belonged to which problem.
What changed
Each failure was classified by its own contract, repaired narrowly, and rerun in the lane that caught it.
Why it matters
Separating causes avoids a broad “make it green” patch that can weaken security or silently change product behavior.

Simplified repair

Turn one red wall into eleven named jobs.

Broken · simplified example

if pipeline_is_red:
    change_many_files()
    rerun_everything()

A blanket response mixes unrelated causes and makes review harder.

Fixed · simplified example

for gate in failed_gates:
    cause = classify(gate)
    repair(cause.contract)
    rerun(gate)

Each gate gets one reason, one bounded correction, and one confirming rerun.

Illustration only — not copied from private source.

How it was checked

Historical PR-reported validation

The merged history enumerates all eleven failing gates and their corresponding corrections across backend, frontend, security, and supply-chain lanes. Those checks were not rerun for this portfolio page.