Start with the official objective structure

The four AB-400 areas are build Microsoft Power Platform solutions (15–20%), extend the user experience (25–30%), extend Microsoft Power Platform (35–40%), and develop integrations (10–15%). These are study-domain weight ranges rather than a fixed distribution for an individual test form. Create a tracking sheet with one implementable exercise and a failure scenario for each objective. Read the current Microsoft study guide before using older tutorials; product names, controls and developer tooling can change.

Dataverse schema and security

An application needs well-defined entities, relationships, ownership and access. Compare organization-owned and user/team-owned tables and select security roles appropriate to business tasks. Use column permissions and business rules as needed, but enforce sensitive decisions on the server or supported access boundary rather than relying on hidden form controls. Practice a record lifecycle with create/update/delete and examine how cascades, alternate keys, choice values and solution dependencies affect integration. Test with nonprivileged identities.

Canvas apps, model-driven apps and Power Fx

Choose canvas apps where a tailored interaction is essential and model-driven apps where Dataverse-centered workflows and governed data models are central. Use Power Fx for responsive UI logic while respecting delegation and data limits. Reproduce a common bug: a filter appears correct over a small dataset but produces incomplete results at scale. Review formula errors and access failures separately. The user experience is only correct when it remains accurate for realistic data volume and user permissions.

Power Apps component framework

PCF controls can add interactive capabilities that the standard components do not supply. Understand the manifest, configuration properties, lifecycle methods, data binding and event handling. Build a control that accepts a value, validates it, displays an accessible error and returns a predictable update. Test keyboard use, dynamic sizes and a slow input provider. A control should not be responsible for approving a server-side transaction or storing API credentials in client-side code.

Dataverse plugins and custom APIs

Use server-side extensibility for business logic that must apply consistently across clients. Understand transaction context, exception behavior, service identities, security permissions and instrumentation. Practice rejecting invalid changes without modifying unrelated records. Know when to perform synchronous validation and when to queue work asynchronously. Treat errors from downstream services carefully to avoid endless retries or inconsistent state. Trace a faulty plugin in a nonproduction environment before applying a corrective change.

Power Automate and process automation

Build a workflow with a clear trigger, input contract, exception branch and success criterion. Integrate a Dataverse event with an approved external service. Demonstrate idempotency when a flow is re-executed, and plan what happens if an API times out after performing a write. Use connection references, environment variables and ALM discipline instead of hard-coding environment-specific secrets. Describe why a scheduled flow, real-time user action and event-driven server extension may require different safeguards.

Connectors, APIs and Azure services

For custom connectors, understand API descriptions, authentication choices, rate limiting, paging, versioning and response validation. Test both unauthorized and authorized cases. Explain which API calls should be delegated as the user and which should use an approved workload identity. A well-structured integration handles transient errors without creating duplicate side effects. Use supported Azure services where appropriate, but keep the assessment tied to the stated AB-400 objectives rather than an arbitrary list of Azure products.

Application lifecycle management

Place changes in an appropriate development environment, use source control for code and solution definitions, and deploy through a test path before production. Contrast managed and unmanaged solutions and inspect dependencies on connections, environment settings and third-party services. Create a simple CI check that validates a solution and tests a representative extension. Document how a failed deployment is detected and how the previous compatible version can be restored. A rollback plan that ignores schema changes is incomplete.

Copilot Studio and agent integrations

AI-assisted development and agentic workflows appear in the current developer context. Describe which decision is made by a model, which by deterministic application logic and which requires a person. An agent should retrieve only permitted data and invoke only authorized tools. Evaluate incorrect instructions in documents, inconsistent responses, secrets exposure and an outage of the model provider. Build traceable approval gates and monitoring rather than depending on prompt instructions to enforce security.

Make these notes a practical review checklist

For each concept, answer four questions: what problem it solves, which platform component owns it, what can fail, and how you would test the failure. Build a Dataverse-backed app with a PCF extension, workflow, external API and a restricted AI-assisted task. Then make deliberate errors in the permission model and deployment configuration. A candidate who can diagnose those errors without guessing is better prepared than one who has memorized dozens of outdated question stems.