Medium — AZ-400 Practice Quiz

Question 1

Your team uses Azure App Configuration to manage feature flags for a web application deployed through Azure Pipelines. The product owner wants to enable a new checkout experience only for internal beta testers (identified by a specific Azure AD group) while keeping it disabled for all other users, without redeploying the application. Which App Configuration feature flag capability should you use?

Accepted Answer

A Targeting filter that specifies included groups and users for the feature flag

Answer

A Time Window filter that enables the flag during a scheduled maintenance window

Answer

A Percentage (Microsoft.Percentage) filter set to gradually increase the rollout

Answer

Separate App Configuration stores per environment with the flag hard-coded on in one store

Question 2

Your team runs an ASP.NET Core API instrumented with Application Insights. Support reports that certain checkout requests fail intermittently, but the front-end only logs a generic 500 error. You need a KQL query in Log Analytics that returns each failed checkout request together with the specific exception thrown during that same request execution, so you can identify the root-cause exception type per failing operation. Which query correctly correlates the two telemetry types?

Accepted Answer

requests | where success == false and name contains "checkout" | join kind=inner (exceptions) on operation_Id | project timestamp, name, resultCode, type, outerMessage

Answer

requests | where success == false and name contains "checkout" | union exceptions | project timestamp, name, resultCode, type

Answer

exceptions | where type contains "checkout" | join kind=leftouter (requests) on session_Id | project timestamp, type, resultCode

Answer

requests | where success == false and name contains "checkout" | lookup exceptions on itemId | project timestamp, name, type

Question 3

Your team runs an Application Insights-instrumented web API. Product management wants a weekly report showing the 99th percentile server response time grouped by each API operation (URL path), covering the last 7 days. You need to write a KQL query against the requests table that returns one row per operation with its p99 duration. Which query satisfies this requirement?

Accepted Answer

requests | where timestamp > ago(7d) | summarize percentile(duration, 99) by operation_Name

Answer

requests | where timestamp > ago(7d) | summarize avg(duration) by bin(timestamp, 1d)

Answer

requests | where timestamp > ago(7d) | top 99 by duration desc by operation_Name

Answer

requests | where timestamp > ago(7d) | project duration, operation_Name | render timechart

Question 4

Your team runs a customer-facing web API on Azure App Service. Leadership wants proactive detection of outages from multiple global locations, including verification that a login endpoint returns a valid token before the checkout endpoint is exercised, all without deploying any code into the application. You are configuring Application Insights. Which monitoring capability should you implement?

Accepted Answer

A custom availability test that runs a multi-step sequence of authenticated requests submitted via the TrackAvailability API from an Azure Function

Answer

A standard (URL ping) availability test targeting the API base URL from five regions

Answer

A Smart Detection rule for failure anomalies on server response codes

Answer

A live metrics stream dashboard shared with the operations team

Question 5

Your microservices application is instrumented with Application Insights across five services. A customer reports that a specific checkout request failed intermittently. You have the operation_Id from the failed request captured in a support ticket. You need to reconstruct the complete end-to-end distributed trace — including all requests, dependencies, and exceptions across every service — for that single transaction using KQL. Which query approach correctly retrieves the full trace?

Accepted Answer

union requests, dependencies, exceptions, traces | where operation_Id == '<id>' | order by timestamp asc

Answer

requests | where operation_ParentId == '<id>' | project timestamp, name, resultCode

Answer

dependencies | where session_Id == '<id>' | summarize count() by target

Answer

requests | join kind=inner (dependencies) on cloud_RoleName | where operation_Name == '<id>'

Question 6

Your team runs a microservice on Azure App Service instrumented with Application Insights. After a recent release, users report intermittent slowness. You suspect a downstream SQL dependency is the cause. You need a KQL query that returns, for the last 24 hours, the 95th percentile duration of failed dependency calls grouped by the target dependency, so you can identify which dependency degraded most. Which query should you run in the Logs (Analytics) blade?

Accepted Answer

dependencies | where timestamp > ago(24h) | where success == false | summarize percentile(duration, 95) by target

Answer

requests | where timestamp > ago(24h) | summarize avg(duration) by name | where success == false

Answer

dependencies | where timestamp > ago(24h) | summarize count() by resultCode | render timechart

Answer

exceptions | where timestamp > ago(24h) | summarize percentile(duration, 95) by cloud_RoleName

Question 7

Your team uses Application Insights with Log Analytics. The reliability lead wants a dashboard tile showing the trend of the 95th percentile server response time bucketed into 15-minute intervals over the last 24 hours, visualized as a line chart. Which KQL query produces the correct result?

Accepted Answer

requests | where timestamp > ago(24h) | summarize percentile(duration, 95) by bin(timestamp, 15m) | render timechart

Answer

requests | where timestamp > ago(24h) | summarize avg(duration) by bin(timestamp, 15m) | render barchart

Answer

requests | where timestamp > ago(24h) | summarize percentile(duration, 95) by duration | render timechart

Answer

requests | where timestamp > ago(24h) | top 95 by duration | render timechart

Question 8

A production ASP.NET Core web app is instrumented with Application Insights. During a promotional event, on-call engineers report that the app is intermittently returning 500 errors, and they need to observe request rates, failure rates, and server CPU in real time as the traffic surges — with sub-second latency and without waiting for telemetry to be ingested and indexed. Which Application Insights capability should they use?

Accepted Answer

The Live Metrics Stream, which shows near real-time performance and failure counters without persisting the data to the workspace

Answer

A scheduled Log Analytics KQL query over the requests table that runs every 60 seconds

Answer

The Application Map to visualize dependencies between components

Answer

A multi-step availability test executed from five geographic regions

Question 9

Your team runs a customer-facing web API instrumented with Application Insights. Leadership wants to be automatically notified when the failure rate of the API rises abnormally compared to its typical baseline, without manually defining static numeric thresholds that would need constant tuning as traffic patterns change throughout the day. You must configure this with the least ongoing maintenance. What should you use?

Accepted Answer

Application Insights Smart Detection (failure anomalies) to detect abnormal rises in the failure rate using machine learning against the historical baseline

Answer

A static metric alert rule in Azure Monitor on the 'Failed requests' metric with a fixed threshold of 50 failures over 5 minutes

Answer

A scheduled log query alert that runs a KQL query every hour counting exceptions and emails the team a summary

Answer

A Container Insights alert on pod restart count in the AKS cluster hosting the API

Question 10

Your team publishes an internal .NET library to an Azure Artifacts feed. Leadership requires that every package version encode the release date so consumers can immediately identify the age of a dependency, and the versioning scheme must not require manual increment of a major/minor number for each release. The library is released on an unpredictable cadence, sometimes multiple times per day. Which versioning approach should you implement in the Azure Pipelines build that produces the NuGet package?

Accepted Answer

Use CalVer with a version format such as YYYY.MM.DD.rev, generating the revision from a pipeline counter expression so multiple same-day builds remain unique.

Answer

Use strict SemVer (MAJOR.MINOR.PATCH) and manually bump the PATCH number in the .csproj before each release.

Answer

Publish every build with the fixed version 1.0.0 and rely on the Azure Artifacts feed view (@Local, @Prerelease, @Release) to distinguish releases.

Answer

Append the Git commit SHA as the entire package version so each build is uniquely identifiable.

Question 11

Your organization uses an Azure Artifacts feed named 'Shared-Libs' to distribute internal NuGet packages. A new team of developers needs to restore packages from this feed in their local builds and in a pipeline, but they must not be able to publish new package versions or delete existing ones. The feed currently grants the 'Project Collection Build Service' the Contributor role. What is the most appropriate way to grant the new team the access they require while following least-privilege principles?

Accepted Answer

Add the team's security group to the feed with the Reader role.

Answer

Add the team's security group to the feed with the Collaborator role.

Answer

Add the team's security group to the feed with the Contributor role.

Answer

Add the team's security group as a feed Owner and disable publishing at the view level.

Question 12

Your team publishes NuGet packages to an Azure Artifacts feed. Developers continuously push prerelease packages during active development, but downstream consumer teams must only be able to restore packages that have passed QA validation. You want to promote validated packages so consumers can reference a stable set without changing their feed source URL to a different feed. Which approach should you implement?

Accepted Answer

Create separate @Prerelease and @Release views on the feed and promote a package to the @Release view after QA passes; have consumers connect to the @Release view endpoint.

Answer

Create a second Azure Artifacts feed named 'Release' and use a pipeline task to copy validated packages between feeds, pointing consumers at the second feed.

Answer

Configure an upstream source on the consumer feed that pulls only packages tagged as validated from the development feed.

Answer

Apply a retention policy that automatically deletes prerelease packages so only validated stable packages remain visible to consumers.

Question 13

Your team publishes internal NuGet packages to an Azure Artifacts feed. Developers consuming these packages report that when they step into library code during debugging in Visual Studio, they cannot see the original source or line-level breakpoints. You want to enable full source-level debugging of the published packages without manually distributing PDB files. What should you configure in the build pipeline that produces the packages?

Accepted Answer

Add a PublishSymbols task that publishes the .pdb files to the Azure Artifacts symbol server, and have developers configure Visual Studio to use the organization's symbol server.

Answer

Enable the retention policy on the feed to keep all package versions indefinitely so the PDBs are never deleted.

Answer

Set the NuGet package version to a SemVer prerelease tag so Visual Studio automatically downloads matching debug symbols.

Answer

Configure an upstream source on the feed pointing to nuget.org so symbols are resolved from the public symbol server.

Question 14

Your team maintains an Azure Artifacts feed named 'Contoso-NuGet' for internal .NET packages. Developers currently restore both your internal packages and public packages from nuget.org, but you want a single feed URL in the NuGet.config that resolves internal packages while also caching and vetting public packages so the same versions are always available even if nuget.org is unavailable. You also need to promote only tested internal package versions to a 'Release' view consumed by production build pipelines. Which combination of Azure Artifacts capabilities should you configure?

Accepted Answer

Enable nuget.org as an upstream source on the feed, and publish tested packages to a 'Release' view via promotion, pointing production pipelines at the '@Release' view URL.

Answer

Create a separate feed for public packages and reference both feed URLs in NuGet.config, using retention policies to keep only release-quality versions.

Answer

Set the feed's default view to '@Local' and disable upstream sources, then manually mirror required nuget.org packages by uploading .nupkg files.

Answer

Enable nuget.org as an upstream source and use branch policies to gate which package versions appear in the '@Prerelease' view for production pipelines.

Question 15

Your team runs automated tests in an Azure Pipelines build that publishes test results to Azure DevOps. Leadership wants a dashboard widget that shows the trend of automated test pass rate over the last 12 weeks so they can spot regressions in test quality across sprints. The data must reflect historical results, not just the latest run. Which dashboard widget should you configure to meet this requirement?

Accepted Answer

The Test Results Trend (Advanced) widget backed by the Analytics service, filtered by pipeline and grouped by outcome over the last 12 weeks

Answer

The Deployment Status widget scoped to the release pipeline

Answer

The Query Results widget bound to a work item query for Test Case work items

Answer

The Build History widget pinned to the CI pipeline definition

Question 16

Your team lead wants a dashboard that answers a single question: 'Once a developer starts actively working on a work item, how long does it take on average to reach the Done state?' The team uses Azure Boards with a Kanban board whose columns map to the states New, Active, Resolved, and Closed (mapped to Done). Management is NOT interested in how long items sat in the backlog before work began. Which Azure Boards analytics widget should you add to the dashboard to answer this question?

Accepted Answer

Cycle Time widget, configured to measure from the first Active state to the Closed/Done state

Answer

Lead Time widget, configured to measure from work item creation to the Closed/Done state

Answer

Cumulative Flow Diagram widget showing counts of items in each board column over time

Answer

Velocity widget showing completed story points per iteration

Question 17

Your team develops in a GitHub repository and tracks work in Azure Boards. Developers want commits and pull requests in GitHub to automatically link to Azure Boards work items so that the deployment/development section of each work item shows the related code changes. You have already installed the Azure Boards app for GitHub and connected the repository. What must developers do in their commit messages or PR descriptions to create these links?

Accepted Answer

Reference the work item using the syntax AB#123 in the commit message or PR title/description.

Answer

Reference the work item using the syntax #123, matching GitHub's native issue-linking syntax.

Answer

Add a GitHub label named azure-boards-123 to the pull request.

Answer

Include the full work item URL in a commit trailer prefixed with Fixes:.

Question 18

Your team uses GitHub for source control and Azure Boards for work tracking. Leadership wants full end-to-end traceability so that anyone viewing a work item can see which pull requests implemented it and whether the associated build succeeded, without leaving Azure Boards. Developers already reference work items in commit messages using AB#123 syntax. What must you configure to satisfy this requirement with the least custom development?

Accepted Answer

Install the Azure Boards app from the GitHub Marketplace and connect the GitHub repository to the Azure Boards project so PRs, commits, and status appear in the Development section of work items.

Answer

Create a GitHub Actions workflow that calls the Azure DevOps REST API on each PR to append a comment to the linked work item with the build result.

Answer

Enable a service hook in Azure DevOps that posts to a GitHub webhook whenever a work item state changes so GitHub stores the traceability link.

Answer

Configure branch policies in Azure Repos requiring linked work items, then mirror the GitHub repository into Azure Repos on a schedule.

Question 19

Your organization stores code in GitHub and manages sprint planning in Azure Boards. Developers work in GitHub using GitHub Flow, opening feature branches and pull requests. Product managers want work item state in Azure Boards to automatically move to 'Closed' when the linked pull request is merged, without developers manually updating boards. You have installed the Azure Boards app on the GitHub organization. Which configuration achieves automatic state transition on PR merge?

Accepted Answer

Add an 'AB#<id>' mention in the PR description or a commit message using a state-transition keyword (e.g., 'Fixes AB#123'), which the Azure Boards GitHub integration uses to close the linked work item on merge to the default branch.

Answer

Configure a branch policy in Azure Repos requiring linked work items, which will automatically close the item when the GitHub PR merges.

Answer

Enable the 'Automatically close work items' toggle in Azure Boards Project Settings > GitHub connections, then link the PR with AB# and closure happens regardless of keyword.

Answer

Create a GitHub Actions workflow triggered on 'pull_request closed' that calls the Azure DevOps REST API with a service connection to update every referenced work item state.

Question 20

Your engineering organization uses Azure Boards for backlog management and Slack for team communication. The delivery lead wants engineers to receive a Slack message in the #team-releases channel whenever a work item in the 'Delivery' area path transitions to the 'Resolved' state, but they do NOT want notifications for any other state change or area path. The solution must require minimal ongoing maintenance and avoid custom code hosting. Which approach should you implement?

Accepted Answer

Configure the Azure Boards app for Slack and create a subscription with a filter on area path and the 'work item updated' event scoped to the Resolved state.

Answer

Create an outgoing service hook in Azure DevOps that posts to a Slack incoming webhook on every 'work item updated' event, then filter messages inside Slack with a workflow rule.

Answer

Deploy an Azure Function triggered by an Azure Boards service hook that inspects each event payload and forwards only matching events to Slack.

Answer

Enable the built-in Azure DevOps email notification for the Delivery team and configure Slack to ingest the notification mailbox.

Question 21

Your engineering leadership wants a dashboard metric that measures the total elapsed time from the moment a customer feature request is created as a work item until it is marked Done, so they can quantify overall responsiveness to customer demand. The team already tracks how long items spend actively being worked. Which Azure Boards analytics metric should you add to the dashboard to satisfy leadership's request?

Accepted Answer

Lead Time, measured from work item creation to closure

Answer

Cycle Time, measured from when work becomes active to closure

Answer

Mean Time to Recovery (MTTR) for the deployment environment

Answer

Velocity, measured as completed story points per sprint

Question 22

Your team wants a dashboard widget that visualizes how many User Stories were completed each week over the last three months, grouped by the assigned team member, so the delivery manager can spot workload imbalances. You have an existing flat-list query returning all completed User Stories with their Closed Date and Assigned To fields. What is the most appropriate way to configure this visualization in Azure Boards?

Accepted Answer

Keep the flat-list query and add a Chart for Work Items widget configured as a stacked bar chart grouped by Assigned To with a date-based x-axis

Answer

Convert the query to a tree query and add a Cumulative Flow Diagram widget pointing to it

Answer

Add a Velocity widget scoped to the team and set the number of sprints to display

Answer

Add a Burndown widget bound to a shared query filtered by Closed Date

Question 23

Your team runs sprints in Azure Boards and deploys via Azure Pipelines. Product management wants an automatically generated release notes document published to the team wiki after each successful production deployment. The notes must list all completed User Stories and Bugs associated with the commits included in that release, without requiring anyone to manually curate the list. Which approach best satisfies this requirement with the least ongoing maintenance?

Accepted Answer

Add a pipeline step that uses the built-in release notes generation to collect associated work items from the build's linked commits and publish the output as a Markdown page to the wiki via the Azure DevOps REST API.

Answer

Create a shared query in Azure Boards filtered by iteration path and manually copy its results into the wiki after each deployment.

Answer

Configure a Teams channel webhook so that every work item state change posts a message, then archive the channel history as the release notes.

Answer

Enable a dashboard widget showing the sprint burndown and export it as a PDF attached to each release.

Question 24

Your team collaborates primarily in Microsoft Teams. Product owners want a dedicated Teams channel to automatically receive a notification whenever any work item in the 'Payments' area path on the Azure Boards project transitions to the 'Resolved' state, so testers can begin verification promptly. You must configure this with the least administrative effort and without writing custom code. What should you do?

Accepted Answer

Install the Azure Boards app in the Teams channel and create a subscription filtered by area path and the 'Resolved' state transition.

Answer

Create an Azure DevOps service hook that posts to an Incoming Webhook connector in the Teams channel for every work item updated event.

Answer

Configure a personal notification subscription in Azure Boards for each product owner filtered to the 'Payments' area path.

Answer

Build an Azure Logic App triggered by the Azure Boards connector that filters work items and posts an adaptive card to the channel.

Question 25

Your platform team wants developers to self-provision ephemeral test environments in Azure on demand, but the environments must only use pre-approved infrastructure templates, be deployed into specific subscriptions per project, and be automatically tracked for cleanup. Developers should request environments through a catalog without having direct rights to write ARM/Bicep at will. Which Azure service and configuration best meets these requirements?

Accepted Answer

Azure Deployment Environments with a dev center, environment types mapped to target subscriptions, and a catalog of environment definitions sourced from a Git repository

Answer

Grant each developer Contributor on a shared subscription and provide a Bicep module registry they can deploy from manually

Answer

Create Azure DevOps release pipelines with manual approval gates that run az deployment commands using a service connection

Answer

Use Azure Blueprints assignments applied at the management group level for every developer request