Developer Guides

In-depth technical guides on JSON, regular expressions, Git diffs, JWT tokens, and more — written for working software engineers.

10 guides for /diff-checkerShow all →
·8 min read

How to Read a Git Diff

Understanding the unified diff format, hunk headers, and conflict markers is essential for effective code review and merge conflict resolution.

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·8 min read

Myers, Patience, Histogram: The Diff Algorithms Behind Git Explained

Most developers use git diff every day without knowing what algorithm generates those hunks. Understanding Myers, Patience, and Histogram algorithms makes you a sharper code reviewer.

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·8 min read

Code Review Is Broken, and Diff Tools Are Part of the Problem

The line-by-line diff view encourages nitpicking over substance and misses architectural issues. This is a hot take on why modern code review is failing and what to do instead.

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·8 min read

Three-Way Merge: The Algorithm That Makes Git Work

Every Git merge uses three-way merge, but few developers understand why. Understanding the common ancestor algorithm transforms how you think about rebasing, cherry-picking, and conflicts.

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·7 min read

Why Text Diff Is Wrong for JSON (And What to Use Instead)

Running git diff on JSON files is a category error most teams commit daily. Text diff treats JSON as lines of characters when the structure is what matters. Here is what to use instead.

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·8 min read

The Right Way to Compare API Responses: Beyond Simple String Diff

Comparing two API responses with a text diff tool produces misleading noise. Timestamps, UUIDs, and ordering will always differ semantically-meaninglessly. Here is the correct approach.

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·7 min read

Patch Files: The Underrated Tool Every Developer Should Know

The .patch file format is 50-year-old technology that is as relevant as ever. Here is how to create and apply patches, real use cases, and why the Linux kernel still uses email patches.

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·7 min read

Side-by-Side vs Unified Diff: Which Format Actually Helps You Review Code?

The split between unified and side-by-side diff is a genuine religious war in developer tooling. Here is a fair analysis and an opinionated take on when each one is the right choice.

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·8 min read

Configuration Drift Is Silently Breaking Your Systems — Diff Is Your Best Defense

Configuration drift is one of the most insidious sources of production incidents. Regular automated diffing of config files, environment variables, and infrastructure should be standard practice.

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·7 min read

Semantic Versioning Depends on Diffs — So Why Do We Not Automate It?

Semver bumps are determined by human judgment after reading diffs — which is error-prone and inconsistent. The case for automated semantic versioning via diff analysis and conventional commits.

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