---
id: daily-incremental-implementation
name: "incremental-implementation"
url: https://skills.yangsir.net/skill/daily-incremental-implementation
author: addyosmani
domain: ai-ci-cd-deployment
tags: ["ci-cd", "agile-development", "test-automation", "devops", "incremental-development"]
install_count: 3400
rating: 4.40 (20 reviews)
github: https://github.com/addyosmani/agent-skills
---

# incremental-implementation

> 采用薄垂直切片策略渐进式构建功能，每次增量保持系统可测试状态，避免大规模重构风险

**Stats**: 3,400 installs · 4.4/5 (20 reviews)

## Before / After 对比

### 功能开发流程

**Before**:

一次性实现完整功能，开发 2 周后测试发现多处架构缺陷，需要返工重写，浪费 1 周时间

**After**:

按垂直切片分 8 个增量，每半天的增量都可测试验证，早期发现并修正问题，无返工

| Metric | Before | After | Change |
|---|---|---|---|
| 返工时间 | 5天 | 0天 | -100% |

## Readme

# incremental-implementation

# Incremental Implementation

## Overview

Build in thin vertical slices — implement one piece, test it, verify it, then expand. Avoid implementing an entire feature in one pass. Each increment should leave the system in a working, testable state. This is the execution discipline that makes large features manageable.

## When to Use

- Implementing any multi-file change

- Building a new feature from a task breakdown

- Refactoring existing code

- Any time you're tempted to write more than ~100 lines before testing

**When NOT to use:** Single-file, single-function changes where the scope is already minimal.

## The Increment Cycle

```
┌──────────────────────────────────────┐
│                                      │
│   Implement ──→ Test ──→ Verify ──┐  │
│       ▲                           │  │
│       └───── Commit ◄─────────────┘  │
│              │                       │
│              ▼                       │
│          Next slice                  │
│                                      │
└──────────────────────────────────────┘

```

For each slice:

- **Implement** the smallest complete piece of functionality

- **Test** — run the test suite (or write a test if none exists)

- **Verify** — confirm the slice works as expected (tests pass, build succeeds, manual check)

- **Commit** -- save your progress with a descriptive message (see `git-workflow-and-versioning` for atomic commit guidance)

- **Move to the next slice** — carry forward, don't restart

## Slicing Strategies

### Vertical Slices (Preferred)

Build one complete path through the stack:

```
Slice 1: Create a task (DB + API + basic UI)
    → Tests pass, user can create a task via the UI

Slice 2: List tasks (query + API + UI)
    → Tests pass, user can see their tasks

Slice 3: Edit a task (update + API + UI)
    → Tests pass, user can modify tasks

Slice 4: Delete a task (delete + API + UI + confirmation)
    → Tests pass, full CRUD complete

```

Each slice delivers working end-to-end functionality.

### Contract-First Slicing

When backend and frontend need to develop in parallel:

```
Slice 0: Define the API contract (types, interfaces, OpenAPI spec)
Slice 1a: Implement backend against the contract + API tests
Slice 1b: Implement frontend against mock data matching the contract
Slice 2: Integrate and test end-to-end

```

### Risk-First Slicing

Tackle the riskiest or most uncertain piece first:

```
Slice 1: Prove the WebSocket connection works (highest risk)
Slice 2: Build real-time task updates on the proven connection
Slice 3: Add offline support and reconnection

```

If Slice 1 fails, you discover it before investing in Slices 2 and 3.

## Implementation Rules

### Rule 0: Simplicity First

Before writing any code, ask: "What is the simplest thing that could work?"

After writing code, review it against these checks:

- Can this be done in fewer lines?

- Are these abstractions earning their complexity?

- Would a staff engineer look at this and say "why didn't you just..."?

- Am I building for hypothetical future requirements, or the current task?

```
SIMPLICITY CHECK:
✗ Generic EventBus with middleware pipeline for one notification
✓ Simple function call

✗ Abstract factory pattern for two similar components
✓ Two straightforward components with shared utilities

✗ Config-driven form builder for three forms
✓ Three form components

```

Three similar lines of code is better than a premature abstraction. Implement the naive, obviously-correct version first. Optimize only after correctness is proven with tests.

### Rule 0.5: Scope Discipline

Touch only what the task requires.

Do NOT:

- "Clean up" code adjacent to your change

- Refactor imports in files you're not modifying

- Remove comments you don't fully understand

- Add features not in the spec because they "seem useful"

- Modernize syntax in files you're only reading

If you notice something worth improving outside your task scope, note it — don't fix it:

```
NOTICED BUT NOT TOUCHING:
- src/utils/format.ts has an unused import (unrelated to this task)
- The auth middleware could use better error messages (separate task)
→ Want me to create tasks for these?

```

### Rule 1: One Thing at a Time

Each increment changes one logical thing. Don't mix concerns:

**Bad:** One commit that adds a new component, refactors an existing one, and updates the build config.

**Good:** Three separate commits — one for each change.

### Rule 2: Keep It Compilable

After each increment, the project must build and existing tests must pass. Don't leave the codebase in a broken state between slices.

### Rule 3: Feature Flags for Incomplete Features

If a feature isn't ready for users but you need to merge increments:

```
// Feature flag for work-in-progress
const ENABLE_TASK_SHARING = process.env.FEATURE_TASK_SHARING === 'true';

if (ENABLE_TASK_SHARING) {
  // New sharing UI
}

```

This lets you merge small increments to the main branch without exposing incomplete work.

### Rule 4: Safe Defaults

New code should default to safe, conservative behavior:

```
// Safe: disabled by default, opt-in
export function createTask(data: TaskInput, options?: { notify?: boolean }) {
  const shouldNotify = options?.notify ?? false;
  // ...
}

```

### Rule 5: Rollback-Friendly

Each increment should be independently revertable:

- Additive changes (new files, new functions) are easy to revert

- Modifications to existing code should be minimal and focused

- Database migrations should have corresponding rollback migrations

- Avoid deleting something in one commit and replacing it in the same commit — separate them

## Working with Agents

When directing an agent to implement incrementally:

```
"Let's implement Task 3 from the plan.

Start with just the database schema change and the API endpoint.
Don't touch the UI yet — we'll do that in the next increment.

After implementing, run `npm test` and `npm run build` to verify
nothing is broken."

```

Be explicit about what's in scope and what's NOT in scope for each increment.

## Increment Checklist

After each increment, verify:

-  The change does one thing and does it completely

-  All existing tests still pass (`npm test`)

-  The build succeeds (`npm run build`)

-  Type checking passes (`npx tsc --noEmit`)

-  Linting passes (`npm run lint`)

-  The new functionality works as expected

-  The change is committed with a descriptive message

## Common Rationalizations

Rationalization
Reality

"I'll test it all at the end"
Bugs compound. A bug in Slice 1 makes Slices 2-5 wrong. Test each slice.

"It's faster to do it all at once"
It *feels* faster until something breaks and you can't find which of 500 changed lines caused it.

"These changes are too small to commit separately"
Small commits are free. Large commits hide bugs and make rollbacks painful.

"I'll add the feature flag later"
If the feature isn't complete, it shouldn't be user-visible. Add the flag now.

"This refactor is small enough to include"
Refactors mixed with features make both harder to review and debug. Separate them.

## Red Flags

- More than 100 lines of code written without running tests

- Multiple unrelated changes in a single increment

- "Let me just quickly add this too" scope expansion

- Skipping the test/verify step to move faster

- Build or tests broken between increments

- Large uncommitted changes accumulating

- Building abstractions before the third use case demands it

- Touching files outside the task scope "while I'm here"

- Creating new utility files for one-time operations

## Verification

After completing all increments for a task:

-  Each increment was individually tested and committed

-  The full test suite passes

-  The build is clean

-  The feature works end-to-end as specified

-  No uncommitted changes remain

Weekly Installs615Repository[addyosmani/agent-skills](https://github.com/addyosmani/agent-skills)GitHub Stars8.9KFirst SeenFeb 16, 2026Security Audits[Gen Agent Trust HubPass](/addyosmani/agent-skills/incremental-implementation/security/agent-trust-hub)[SocketPass](/addyosmani/agent-skills/incremental-implementation/security/socket)[SnykPass](/addyosmani/agent-skills/incremental-implementation/security/snyk)Installed oncodex598opencode594github-copilot593gemini-cli593cursor593kimi-cli592

---
*Source: https://skills.yangsir.net/skill/daily-incremental-implementation*
*Markdown mirror: https://skills.yangsir.net/api/skill/daily-incremental-implementation/markdown*