AB-400 skills outline: the four exam domains and what is new

Three skill areas: design the technical architecture, design solution components and implement ALM. This is the decisions domain: where business logic belongs (cloud services, client-side processing, business rules, plug-ins or automation), when to use standard, virtual or elastic tables versus connectors, and how managed environments, data policies, security roles, teams and business units affect your components.

The new material is in the choices: when to use deterministic or non-deterministic methods for business logic, when to use a code app, a generative page, a PCF component, a web resource, an interactive agent or an MCP app widget for the user experience, and when to build an agent in Microsoft Foundry or in Copilot Studio. Component design now includes MCP servers alongside custom connectors, Copilot Studio workflows alongside Power Automate, and monitoring with Application Insights and Power Platform monitor alerts.

ALM keeps the familiar items (dependencies, environment variables, solution layers) and leans further into automation: implementing and extending Power Platform Pipelines and building CI/CD with Power Platform Build Tools. The change log marks all three areas of this domain as major changes.

The domain that grows the most: it was 10–15% in PL-400. Two areas carry over from PL-400 with minor changes: client scripting in model-driven apps (Client API object model, event handler registration, calls to the Dataverse Web API, commands and buttons with Power Fx and JavaScript, navigation, dialogs and notifications) and PCF code components (lifecycle events, manifest, interfaces, packaging and deployment, and the Device, Utility and Web API features).

The other two are new and cover Power Apps code apps. Build: configure them to use Power Platform connections, Dataverse tables, table and metadata operations, Dataverse actions and functions, Power Automate cloud flows, Copilot Studio agents and environment variables. Deploy and manage: Content Security Policy settings, monitoring with Application Insights, packaging, deploying and sharing, troubleshooting with Monitor and browser tools, and optimizing performance and resource usage.

If you are coming from PL-400, most of your extra study is here: code apps are two of the four areas in a domain worth up to 30% of the exam.

The heaviest domain, with five areas. Dataverse plug-ins: event execution pipeline stages, execution context, images, the Organization service, performance, custom API messages, the Plug-in Registration Tool, business events and, new, Power Platform managed identity for plug-ins. The change log marks it as a minor change: what you knew from PL-400 still applies.

Platform APIs (major change): operations with the Dataverse Web API and the Organization service, API limit retry policies, optimizing for performance, concurrency, transactions and bulk operations, OAuth authentication, asynchronous logic with background operations, and the Dataverse SDKs for .NET and Python. Azure Functions is unchanged: long-running operations, scheduled and event-driven triggers, and authentication with managed identities.

The automation area becomes Power Automate cloud flows and Copilot Studio workflows: complex expressions, flow control and error handling, trigger filters and retry policies, child flows, and Dataverse connector authentication with service principals. The domain closes with the new area on Microsoft Foundry agents built with code: integrating them through Power Platform MCP servers, connecting them to Copilot Studio agents, giving them Dataverse data through Work IQ, and consuming Copilot Studio agents with the Copilot Studio client library.

Three areas. Publish and consume Dataverse events: IServiceEndpointNotificationService, the Plug-in Registration Tool, registering service endpoints (webhooks, Azure Service Bus, Azure Event Hub) and recommending options for listening to events. Synchronization for Dataverse data: change tracking, alternate keys and the UpsertRequest message.

The third, custom connectors, sat in a different domain in PL-400 and moves here with minor changes: authentication, policy templates to modify connector behavior at runtime, importing definitions from OpenAPI, Azure services and GitHub, creating a connector for an Azure service, developing an Azure Function for use in a connector, extending the OpenAPI definition and writing code to transform data.

The study guide's change log marks several PL-400 areas as removed: creating a technical design as its own domain (architecture and component design move into domain 1), configuring and troubleshooting Power Platform, implementing Power Apps improvements, advanced canvas app features, and optimizing and troubleshooting apps. In practice the configuration-leaning material leaves and more professional development comes in.

To study sensibly, spend time in proportion to weight and novelty. Plug-ins and APIs still decide the pass; code apps and Foundry agents are what you will not have seen if you were preparing PL-400. The block-by-block plan is in how to prepare for AB-400, and the background in PL-400 is becoming AB-400.