slice

name	slice
description	Break overwhelming development tasks into right-sized, independently deliverable units — diagnoses why tasks stall and applies decomposition patterns. Use when a task feels too big to estimate, when unsure where to start, when blocked by dependencies, or when scope keeps growing. Trigger phrases: "task too big", "can't estimate", "overwhelmed by scope", "where do I start", "break this down", "epic needs breakdown", "slice this up", "/empire-dev:slice".
compatibility	Designed for Claude Code (or similar agents).

The goal isn't more tasks — it's the right tasks. Small enough to understand completely. Large enough to deliver value. Independent enough to avoid blocking.

Cognitive Limit	Threshold	Implication
Working memory	7±2 items	Max concepts per task
Context switch recovery	23 minutes	Minimize task switching
Files examined	15-20 max	Bound task scope
Days before completion drops	2-3 days	Keep tasks under this

Duration	Completion Rate
< 2 hours	95%
2-4 hours	90%
4-8 hours (1 day)	80%
2-3 days	60%
1 week	35%
> 2 weeks	<10%

SHOULD read CONTEXT.md at repo root before proceeding — use its vocabulary verbatim; never substitute synonyms. SHOULD scan docs/adr/ for decisions in the area under analysis — respect accepted ADRs; do not re-litigate closed decisions. If neither exists, proceed without them. Do not create these files unprompted.

TD1: Too Big to Understand

Symptoms: Estimates range wildly. Can't hold all requirements in mind. More than 7 concepts to track.

Interventions: Apply INVEST criteria: Independent, Negotiable, Valuable, Estimable, Small, Testable. Use vertical slicing (each slice independently deployable). Apply walking skeleton (minimal end-to-end first).

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TD2: No Clear Entry Point

Symptoms: Multiple valid starting points. Paralysis. Everything seems connected.

Interventions: Front-load risk: start with highest-uncertainty items. Tracer bullet: minimal proof of concept. Find the walking skeleton: thinnest slice through all layers.

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TD3: Dependency Problems

Symptoms: "Blocked on X." Diamond dependencies. Coordination overhead.

Interventions: Interface contracts: define API, mock while implementing. Feature flags: deploy independently, enable when ready. Branch by abstraction: create layer, swap implementations.

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TD4: No Clear Done Criteria

Symptoms: "Almost done" forever. No way to verify completion.

Interventions: Define acceptance criteria (Given / When / Then). Time-box to force prioritization. Define explicit out-of-scope items.

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TD5: Scope Creep

Symptoms: Task keeps growing. "While we're here" additions.

Interventions: Freeze scope, spawn new tasks for additions. Define minimum viable version. Ship smallest version that solves the problem.

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TD6: Need Spike First

Symptoms: Estimate variance > 4x. New technology. Multiple viable approaches.

Interventions: Time-boxed spike (8 hours max). Deliverables: options, POC, trade-offs, revised estimate. Spike-then-implement pattern.

Vertical Slicing (preferred for features) — each slice is independently deployable and delivers value end-to-end.

Feature: User Profile Management

Slice 1: View basic profile (4h)
  - UI: Profile display
  - API: GET /profile
  - DB: Read profile

Slice 2: Edit profile name (6h)
  - UI: Edit dialog
  - API: PATCH /profile/name
  - DB: Update profile

Walking Skeleton (for new systems) — minimal end-to-end first, then flesh out incrementally.

1. Hello World page
2. One GET endpoint
3. Single table
4. Basic deploy

Tracer Bullet (validate architecture) — minimal proof that components can communicate.

Step 1: Minimal Service A (1h) - Hardcoded response
Step 2: Minimal Service B (1h) - Simple transformation
Step 3: Integrate (2h) - Prove they communicate
→ 4 hours to decision point

Fibonacci sizing:

Points	Meaning
1	Trivial, < 1 hour
2	Simple, 1-2 hours
3	Standard, 2-4 hours
5	Moderate, 4-8 hours
8	Complex, 1-2 days
13	Very complex, 2-3 days
21	Too large, must decompose

Three-point estimation:

O = Optimistic (everything perfect)
L = Likely (normal case)
P = Pessimistic (major issues)

PERT estimate: (O + 4L + P) / 6

Before starting any task, verify:

• All requirements fit in working memory?
• Duration under 2-3 days?
• Clear acceptance criteria?
• Dependencies identified and broken where possible?
• Can be completed independently?
• Delivers verifiable value?
• Estimate confidence is high?

Any "no" → further decomposition needed.

Big Bang Delivery — building complete system before any delivery. Fix: vertical slices, incremental value.

Technical Tasks Without Value — "Set up database," "Create service layer." Fix: include in feature tasks: "User can view products (includes DB)."

Research Forever — unbounded investigation. Fix: time-boxed spikes with deliverables.

Perfect Decomposition — over-analyzing before starting. Fix: decompose next 2 weeks only; details for later work emerge.