zoom-out

name	zoom-out
description	Step up a layer of abstraction to map how unfamiliar code fits into the larger system. Use when the user says "zoom out", "bigger picture", "I don't know this area", "give me a map", "where does this fit", is reading code and feels lost, or is about to change unfamiliar code.

Zoom Out

Overview

When you don't know a section of code well, the failure mode is to read line-by-line and never see the shape. Zoom out forces a higher layer of abstraction first: callers, neighbors, role in the system. Read the map before walking the streets.

The Map First

Before explaining what a piece of code does, produce a map of its surroundings:

1. Identify the unit: file, module, package, or service. Name it precisely.
2. Find callers: who uses this? Grep for imports, invocations, or routes.
3. Find neighbors: what siblings live in the same directory or namespace, and what do they do?
4. Find the abstraction above: what does this module belong to? A pipeline, a layer, a bounded context.
5. Find the abstraction below: what does it depend on?

Render the result as a short list or small diagram. Use the project's own vocabulary: the words the codebase uses, not generic CS terms.

Output Shape

Aim for something like:

Module:    src/billing/invoicing/
Role:      Generates invoices from billing periods (one of three writers under /billing)
Above:     /billing — orchestrates subscriptions, invoicing, dunning
Below:     /billing/pricing (rates), /billing/tax (tax calc)
Callers:   src/jobs/monthly_invoice_job.py, src/api/admin/invoices.py
Siblings:  subscriptions/, dunning/

Then, and only then, go deeper.

Anti-Patterns

• Reading line-by-line first. A bottom-up model rarely survives contact with the actual architecture.
• Generic vocabulary. "Service layer, repository pattern" tells the reader nothing about this codebase. Use its own terms.
• Skipping callers. Behavior at the callsite often constrains the module more than the module's own code does.
• Zooming in too soon. If the map isn't done, every implementation detail you read is uncalibrated.

Pairs With

• /naming: domain vocabulary lives in names; zoom-out is naming applied to architecture
• /design: zoom-out surfaces the structure, design evaluates it
• /ia: IA is zoom-out for documentation; same instinct, different medium
• /research: zoom-out maps the inside, research maps the outside

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Adapted from mattpocock/skills.