← Prompt Library / Engineering

Engineering

Legacy Code Explainer

Understand inherited code before touching it: what it does, its hidden assumptions, its danger zones, and a safe path to modifying it.

Explain this legacy code I've inherited: {{code}}. What I need to do with it: {{task}}.

Walk through: what it actually does (plain English, section by section), the implicit assumptions and invariants it depends on (the things that break if violated), its danger zones (global state, side effects, ordering dependencies, magic values), what tests exist vs what's untested, and a safe modification path for my task — smallest change first, with the characterisation tests to write BEFORE touching anything. Flag anything that looks like a bug someone may be depending on.

Fields like {{ this }} are placeholders — replace them with your own details, or let Aria ask you for them.

legacy refactoring comprehension

Run this prompt with your real data

This prompt runs with Aria connected to your email, files, CRM and 40+ other services — and you can schedule it to run automatically.

Start Free Week

More Engineering prompts

Pragmatic Code Reviewer

Review a diff for correctness, security, and readability issues.

Explain This Code

Get a plain-English walkthrough of unfamiliar code.

Write Unit Tests

Generate thorough unit tests for a function.

Debug Assistant

Diagnose an error systematically: likely causes ranked with reasoning, the cheapest test for each, a...

Regex Builder

Build a regular expression from a plain-English requirement — explained token by token, tested again...

SQL From a Question

Turn a plain-English data question into a working SQL query — with the assumptions stated, a readabl...