Azure Functions: serverless compute for AZ-900

The service the exam reaches for whenever code should run on an event and scale to zero — with its triggers, bindings, and plan choices pinned down. AZ-900, 2026 edition.

Here are 7 typical Azure Functions questions in the exam's own style — free, each answer explained, no sign-up.

Straight to the 7 free questions ↓

Azure Functions is the AZ-900’s headline serverless compute service, and the exam tests it with a small set of very repeatable tells. Learn the model, the vocabulary — triggers, bindings, and hosting plans — and this whole cluster of questions turns into free points. The diagram above lays out the shape: an event starts a function, the function runs your short-lived code, and an output binding writes the result somewhere else.

Serverless: no server to manage

“Serverless” does not mean there are no servers. It means you never manage them. Microsoft provisions, patches, and scales the compute; you supply only the code. Functions is event-driven — code runs in response to something happening rather than sitting on an always-on host. That is the core distinction from a virtual machine (which you own from the OS up) and even from Azure App Service (a managed home for a continuously running web app).

Triggers and bindings: how a function starts and moves data

Two words the exam loves:

A trigger is the event that starts the function. Every function has exactly one. Common triggers: an HTTP request, a timer on a schedule, a new queue message, or a blob (file) event in storage.
Bindings are the declarative connections to other services for input and output — so you do not hand-write connection and SDK code. An output binding writes the result out (to a queue, table, or storage). The trigger is really a special input binding that also fires the function.

Keep them straight: trigger = what makes it run; bindings = how data flows in and out.

Consumption vs Premium vs Dedicated

Functions runs on a hosting plan, and picking the right one is a favourite exam scenario:

Consumption — pay per execution, and it scales to zero when idle. You pay nothing while nothing runs. The trade-off is a possible cold start: a function that has been idle takes a moment to spin up on the next request.
Premium — keeps pre-warmed instances ready, so there is no cold start, while still scaling elastically. You pay to keep those instances warm.
Dedicated (App Service plan) — runs on always-on instances you already pay for, useful when you have spare capacity there.

The shortcut: “pay nothing when idle, scale to zero” = Consumption; “always warm, no cold start” = Premium.

Functions vs a full web app

When should you reach for Functions instead of App Service? Use Functions for short-lived, stateless work that fires on an event — a file lands, a message arrives, a schedule ticks. Use App Service for a continuously running web app or API that needs to be up and listening all the time. Short event-driven snippet versus always-on web app: that is the deciding line.

Durable Functions: stateful orchestration

Plain functions are stateless. When a workflow must call several functions in order, wait for each, and track state across the chain, the exam expects one name: Durable Functions — the extension that adds stateful orchestration. You only need to recognise it, not build one.

The real exam mixes multiple-choice, true/false, and drag-and-drop formats; the seven questions above are standard multiple-choice, and every explanation carries a “why not the others” so the wrong options teach you as much as the right one.

A left-to-right flow diagram of how an Azure Function runs. On the left, a box labelled Trigger lists the events that can start a function: an HTTP request, a timer schedule, a new queue message, and a blob (file) event. An arrow points to a central box labelled Function, described as your short-lived, stateless code, no server to manage. From the Function, another arrow points right to a box labelled Output binding, described as a declarative connection that writes the result to another Azure service such as a queue, table, or storage. Underneath the flow a caption reads: Consumption plan — pay per execution, scale to zero when idle. A smaller note to the side reads: Premium and Dedicated plans keep instances warm to avoid cold starts.

7 free AZ-900 practice questions

Answers and explanations — no email wall

AZ-900 Question 1 of 7

A team is told Azure Functions is 'serverless.' A colleague worries there is no infrastructure at all. What does serverless actually mean here in AZ-900 terms?

Answer: A — Servers still run the code, but Microsoft provisions, patches, and scales them for you — you never manage a host.

Serverless does not mean 'no servers' — it means you never see or manage them. Microsoft handles provisioning, patching, and scaling, and you focus only on the code. Why not the others: functions execute on Azure-managed compute, not in the browser. Provisioning and patching a VM yourself is the opposite of serverless — that is the IaaS model. And serverless functions scale out automatically across many instances, not down to a single one. Pro tip: on the exam, 'serverless' = no servers for you to manage, plus automatic scale — not the absence of infrastructure.

AZ-900 Question 2 of 7

A developer wants an Azure Function to run every time a message lands in a storage queue. What is the name for the thing that starts the function when that event happens?

Answer: A — A trigger.

The event that starts a function is called a trigger. Every function has exactly one trigger — here, a queue trigger firing on each new message. Why not the others: a binding connects the function to data (an output binding writes results out), but it does not start the function. An action group belongs to Azure Monitor alerts, not to Functions. A deployment slot is an App Service staging feature, unrelated to how a function is invoked. Pro tip: 'what makes the function start?' is always the trigger — one per function.

AZ-900 Question 3 of 7

Besides an HTTP request, which of these is a valid way to trigger an Azure Function?

Answer: A — A timer on a schedule, so the function runs at fixed intervals.

Azure Functions supports several trigger types, and a timer trigger — running the function on a schedule (say, every hour) — is one of the most common alongside HTTP, queue, and blob triggers. Why not the others: a portal hover is not an event source. Editing an Azure Policy definition governs what resources are allowed and does not invoke a function. And a candidate's click has nothing to do with the running service. Pro tip: know the common triggers as a set — HTTP, timer, queue message, and blob (file) event.

AZ-900 Question 4 of 7

A function needs to read from an incoming queue message and then write its result to a storage table, without you writing connection and SDK code for each. Which Functions feature provides these declarative input/output connections?

Answer: A — Bindings.

Bindings are the declarative way to connect a function to other services for input and output, so you avoid hand-writing SDK and connection code. A trigger is technically a special input binding that also starts the function; additional input and output bindings move data in and out. Why not the others: saying bindings do not exist is simply wrong — they are core to the model. Availability zones are a datacenter resilience concept, and managed disks are VM storage — neither connects a function to data. Pro tip: trigger = what starts it; bindings = how data flows in and out, declared not coded.

AZ-900 Question 5 of 7

A workload runs only a few times a day in short bursts, and the team wants to pay nothing while it is idle. Which Azure Functions hosting plan fits best?

Answer: A — The Consumption plan — you pay per execution and it scales to zero when idle.

The Consumption plan is the pay-per-execution, scale-to-zero option — perfect for spiky, occasional workloads where you want no charge while nothing runs. Why not the others: the Dedicated plan bills for always-on instances whether or not the function fires, so idle time costs money. Premium keeps instances warm on purpose (great for avoiding cold starts, but not free at idle). A VM left running is the most costly and least serverless choice. Pro tip: 'pay nothing when idle' + 'scale to zero' = the Consumption plan.

AZ-900 Question 6 of 7

Under the Consumption plan, a function that has not run for a while can take a moment to spin up on the first request — a 'cold start.' Which plan is designed to avoid this by keeping instances warm?

Answer: A — The Premium plan.

The Premium plan keeps pre-warmed instances ready, eliminating the cold-start delay while still scaling elastically — the go-to when latency matters. Why not the others: the Consumption plan is where cold starts happen, and no free toggle removes them. Cold starts are certainly avoidable — that is precisely what Premium (and Dedicated) address. Azure Advisor is a recommendations service and has nothing to do with hosting functions. Pro tip: cold start is the Consumption trade-off; Premium (or Dedicated) buys always-warm instances to remove it.

AZ-900 Question 7 of 7

A workflow must call several functions in a specific order, wait for each to finish, and keep track of state across the whole chain. Which Azure Functions extension is built for this stateful orchestration?

Answer: A — Durable Functions.

Durable Functions is the extension that adds stateful orchestration to Azure Functions — chaining functions, fanning out and in, and managing state and long-running workflows that plain functions (which are stateless) cannot. Why not the others: a single ordinary function stays stateless no matter its timeout, so it cannot coordinate a multi-step stateful flow. AKS orchestrates containers, not function workflows. Application Insights monitors telemetry; it does not run orchestrations. Pro tip: when a scenario needs stateful, multi-step orchestration, the name to recognize is Durable Functions.

That is exactly how every question in the course works — answer, explanation, why-not. The real set continues in the practice player: 10 free questions, no sign-up.

Continue with the 10 free questions →

Those 7 questions were the start.

The exam does not test whether you recognise a term — it tests whether you can rule out three plausible answers under time pressure. That is what the explanations above are for, and there are 300 more questions built exactly like them.

Collecting questions yourself

Scattered across forums, of unknown age
Answer keys without reasoning
No idea which domain you are weak in

Practising with a system

300 questions in 6 full tests, AZ-900 (2026)
Every option explained — including the wrong ones
Readiness per exam domain, and drills for your weakest

Start free — 10 questions

Straight into the player. No account, no email.

Frequently asked questions

What is a trigger in Azure Functions?

A trigger is the event that causes a function to run. Every function has exactly one trigger — for example an HTTP request, a timer on a schedule, a new message in a queue, or a change to a blob (file) in storage. The trigger both starts the function and, in most cases, hands it the incoming data. Bindings, by contrast, connect the function to other services for input and output but do not start it.

What is the difference between the Consumption and Premium plans?

The Consumption plan bills per execution and scales to zero when idle, so you pay nothing while nothing runs — but a function that has been idle can hit a short 'cold start' on the next request. The Premium plan keeps pre-warmed instances ready to avoid that cold start and suits steadier or latency-sensitive workloads; you pay to keep those instances warm. For AZ-900, remember: Consumption = cheapest and scale-to-zero; Premium = always warm, no cold start.

Are these real exam questions?

No. They are our own questions, written in the style and difficulty of the AZ-900 — never copied from any question bank or the real exam. Reproducing live exam items violates Microsoft's certification agreement and can cost a candidate their certification, and a crammed answer teaches you nothing about the one you have not seen.

Updated for AZ-900 (July 2026). The sample questions above are our own work in the style of the exam — not real exam items. The exam itself is set and marked by the certification body.