# Code Review Systems

> Diff understanding, intent, correctness, maintainability, risk ranking, review workflows, and actionable findings.

Canonical: https://learn.significanthobbies.com/curriculum/concepts/code-review-systems

Diff understanding, intent, correctness, maintainability, risk ranking, review workflows, and actionable findings.

- Difficulty: core
- Tracks: Developer Tools & Code Intelligence

## Mental model

Useful review connects a changed line to behavior and risk. Findings need evidence, severity, scope, and a concrete remediation—not generic style commentary.



## Primary sources

- [Google Engineering Practices — Code Review](https://google.github.io/eng-practices/review/) (doc)
- [Modern Code Review: A Case Study at Google (ICSE-SEIP 2018)](https://research.google/pubs/modern-code-review-a-case-study-at-google/) (paper)
- [Software Engineering at Google — Ch. 9: Code Review](https://abseil.io/resources/swe-book/html/ch09.html) (doc)
- [Software Engineering at Google — Ch. 19: Critique, Google's Code Review Tool](https://abseil.io/resources/swe-book/html/ch19.html) (doc)

## Practice

### Design exercise: Code Review Systems

Diff understanding, intent, correctness, maintainability, risk ranking, review workflows, and actionable findings. Implement designOutline() returning non-empty values for: changeIntent, riskFinding, actionableEvidence. Each value must name a concrete mechanism or decision.

**Expected evidence:** A design outline with changeIntent, riskFinding, actionableEvidence plus an explicit failure mode or trade-off.

## Review prompts

- What makes a review comment actionable rather than noise?

## Build evidence

- **Synthesize: Developer Tools & Code Intelligence** — Build repository-aware tools that analyze, test, review, debug, and safely remediate code. Produce one working system, benchmark, or evidence-backed design that integrates the path.

## Prerequisites

- None assigned.

## Related concepts

- [Static & Dynamic Analysis](https://learn.significanthobbies.com/curriculum/concepts/static-dynamic-analysis)

## Learning paths

- [12-Week Developer Tools & Code Intelligence](https://learn.significanthobbies.com/curriculum/roadmaps/developer-tools-12w)