The customization lifecycle: adapters, registry, rollback

Lesson 4 of 4 in Designing GenAI Solutions and Selecting Models.

When prompting and retrieval stop being enough, models get customized — and what AIP-C01 tests is the lifecycle, not the training (how tuning works lives on the MLA path; here it is out of scope). The professional vocabulary: parameter-efficient adaptation — PEFT, headlined by LoRA — trains small low-rank matrices against a frozen base model, producing adapter artifacts measured in megabytes that are cheap to train, quick to deploy, and swappable per task. Deployment lands on SageMaker AI endpoints for domain-specific fine-tuned models (or back into Bedrock via Custom Model Import for compatible open weights).

Around the artifact sits the machinery the exam actually asks about: the SageMaker Model Registry versions every candidate with an approval status; automated pipelines promote approved versions; rollback strategies keep the previous version deployable in minutes; and lifecycle management retires and replaces models on schedule instead of by surprise.

Customization options through the lifecycle lens
OptionArtifact & cost shapeServingRollback story

Prompt + retrieval only

No training; templates versioned in Prompt Management

Any hosted FM, unchanged

Instant — switch template version

LoRA / PEFT adapters

MB-scale adapters; low training cost; one per task on a shared base

SageMaker AI endpoints for domain-tuned models

Fast — registry keeps every adapter version; redeploy the last good one

Full fine-tune

Full model copy; highest cost; risks forgetting

Bedrock custom model or SageMaker endpoint

Heavier — versions are whole models, so storage and deploys cost more

Custom Model Import

Open weights you already own, brought to Bedrock

Bedrock serverless API, like any hosted FM

Re-point to the previously imported model version

Key terms: LoRA, PEFT, SageMaker Model Registry, Custom Model Import, Fine-tuning

Interactive checkpoint quiz (2 questions) — open this page in a browser to take it.