---
titel: "Targeted feature slices in an existing codebase"
adresse: https://anvil-coder.tech/en/use-cases/feature-slices-bestandscode
beschreibung: "A clearly scoped story is added to an existing application — broken into individual, manageable slices instead of loading the entire codebase at once."
sprache: en
---

Use cases

# Targeted feature slices in an existing codebase

A clearly scoped story is added to an existing application — broken into individual, manageable slices instead of loading the entire codebase at once.

## Case study in full

Synthetic example — illustrative magnitudes, not a measurement.

Stack profile: `typescript-node-20-express` · Data origin: Synthetic example, not a reference run. · Measurement period: —

An existing application is to gain one clearly scoped story — for example an additional API field with matching validation and persistence. The codebase is too large to load in full for a single editing step; the change instead has to break down into individual, manageable slices.

**Out of scope — not automated:** Not automated: formulating the story and prioritizing it in the tracker remain a human decision, as does approving the plan before execution and the merge decision at the end.

### Prerequisites

- A tracker connected to the repository, holding the story to be worked.

- A stack profile describing language, framework and layering of the existing code.

- Guardrails for the existing conventions (naming, layer boundaries, test obligation).

- Approval of the plan derived from the story by a project member.

### Workflow

- The story is read from the tracker and broken down into a plan with individual slices.

- Each slice touches one bounded portion of the codebase, without loading the entire codebase.

- Implementation and validation run per slice, with tests for the new code path.

- Slices that fail validation are reworked before they flow into the overall state.

- The result goes out as a pull request to the repository, linked to the original story.

### Result artifacts

- New and changed files per slice, traceable in the commit history.

- Tests run and their status documented per slice.

- One pull request referencing the originating story in the tracker.

- Feedback on whether the change was accepted or needs further rework.

### Key figures

Scope

**Stories/tickets**

1

**Slices**

7

**Files/modules**

19

Throughput

**Validated slices**

7

**Retries**

2

**Human approvals**

2

Quality

**Checks run**

Unit Tests, Integration Tests, Lint

**Gates passed**

4

**Gates failed**

0

**Remaining debt**

No open debt recorded for this slice.

Resources — no pricing

**Prompt tokens**

100000

**Completion tokens**

40000

**Cache tokens**

130000

**Model calls**

40

**Sandbox runtime**

15 minutes

**Model/stack context**

Stack: Node.js with TypeScript, layered architecture (profile typescript-node-express-layered).

[Log in to see your own run and cost details in the cockpit](https://app.anvil-coder.tech)

Every example on this page was created for illustration. It is not a promise about the duration, quality or cost of a future run of your own — your own figures appear in the cockpit after logging in, within your own tenant context.

## Have a use case of your own?

The free tier is open without a call — create a project, pull an epic, review the result in your own repository.

[Start for free](https://app.anvil-coder.tech/register)[Book a demo](https://anvil-coder.tech/demo)