CCA-FChapters08

Chapter 08

Task Decomposition

Fixed pipeline when the scope is knowable, dynamic when it emerges — and why 14 files need 15 passes.

D1guide part i

8.1

Fixed pipeline

Every step defined before anything runs. Same shape on every input.

documentinput
→
metadataextract
→
dataextract
→
validateschema + rules
→
enrichlookups
→
outputfinal
Prompt chaining as an architecture: predictable, reproducible, auditable step by step.

Use it when the structure is known up front and stability matters more than adaptability — document processing, reviews that always follow one template, mechanical migrations.

8.2

Dynamic adaptive decomposition

The next subtask is generated from what the last one found. The plan does not exist at the start.

1 · map the structure — Glob, Grep2 · found: 3 untested, 2 partial3 · prioritise payments — high risk4 · found an external API dependency5 · mock the API, then write testsplan changesmid-flightno step 5 existedat step 1
Steps 4 and 5 could not have been written in advance — the dependency was discovered, then the plan changed.

8.2b

Which one

Not a preference. It follows from whether the scope is knowable before you start.

signal in the scenariochoose
structure is predictable, always the same templatefixed pipeline
every step is known up frontfixed pipeline
you need stability and reproducible runsfixed pipeline
open-ended investigationdynamic
full scope unknown at the startdynamic
each step depends on what the last one returneddynamic

8.3

Multi-pass review

Ten or more files in one prompt does not review ten files. It reviews some of them.

one prompt · 14 files"review this PR"deep on three, shallow on elevendilution · inconsistent flags · missed bugsone pass per filelocal issues only, ×14integration passinconsistent types · circular dependenciessame tokensusable output
Per-file passes buy consistent depth; the integration pass is the only place cross-file problems can surface.

Recall in 60 seconds

  1. Fixed pipeline = all steps defined up front; use it for predictable, repeatable work.
  2. Dynamic decomposition = subtasks generated from intermediate results.
  3. Signal for dynamic: scope unknown, open-ended investigation, each step depends on the last.
  4. Signal for fixed: same template every time, and you need reproducibility.
  5. A 10+ file PR needs per-file passes, not one big prompt.
  6. One prompt over many files causes attention dilution, inconsistent flagging and missed bugs.
  7. The integration pass is mandatory — cross-file issues appear nowhere else.
  8. Local issues and boundary issues are different passes on purpose.