- A
App Engine Standard Environment.
App Engine Standard can scale to zero when not in use and supports Python, meeting all the startup's needs with minimal overhead.
- B
Compute Engine with managed instance group and autoscaling.
Why wrong: Compute Engine with managed instance group requires managing VMs and cannot scale to zero, leading to higher cost and complexity.
- C
Google Kubernetes Engine with cluster autoscaling.
Why wrong: GKE with cluster autoscaling still requires cluster management and a minimum number of nodes, so it does not scale to zero and adds operational overhead.
- D
Cloud Run.
Cloud Run is a serverless platform that automatically scales to zero and charges only for request processing, making it a valid option for low-traffic containerized apps.
Deploy a Python Web Application That Scales to Zero When Not in Use Using Cloud Run
This PCD practice question tests your understanding of deploying applications. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. A key principle to apply: scaling to zero. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A startup wants to deploy a Python web application with low traffic and minimal operational overhead. They need to automatically scale down to zero when not in use. Which compute option should they choose?
Quick Answer
Cloud Run is the correct choice because it is a fully managed serverless platform that automatically scales your containerized Python web application to zero when there are no incoming requests, charging only for resources used during request processing. This "scale to zero" capability is achieved through Cloud Run’s event-driven architecture, where the underlying infrastructure spins down idle instances and reactivates them on demand, eliminating costs during periods of no traffic. On the Google Professional Cloud Developer exam, this scenario tests your understanding of serverless compute options and their scaling behaviors, often appearing as a direct comparison between Cloud Run, App Engine, and Compute Engine. A common trap is selecting App Engine Standard, which also scales to zero but requires a specific runtime environment, whereas Cloud Run offers full container portability and faster cold starts for Python apps. Memory tip: think "Run to zero" — Cloud Run is the only option that combines container flexibility with automatic scale-down to zero instances.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
App Engine Standard Environment.
Both App Engine Standard Environment and Cloud Run satisfy the requirements of low traffic, minimal operational overhead, and scaling to zero. App Engine Standard can scale to zero when no requests are incoming and supports Python, making it a valid choice. Cloud Run also scales to zero automatically and is fully managed, but for a simple Python web app, App Engine Standard offers even less configuration. Therefore, both options are correct.
Key principle: Scaling to zero
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
App Engine Standard Environment.
Why this is correct
App Engine Standard can scale to zero when not in use and supports Python, meeting all the startup's needs with minimal overhead.
Related concept
Scaling to zero
- ✗
Compute Engine with managed instance group and autoscaling.
Why it's wrong here
Compute Engine with managed instance group requires managing VMs and cannot scale to zero, leading to higher cost and complexity.
- ✗
Google Kubernetes Engine with cluster autoscaling.
Why it's wrong here
GKE with cluster autoscaling still requires cluster management and a minimum number of nodes, so it does not scale to zero and adds operational overhead.
- ✓
Cloud Run.
Why this is correct
Cloud Run is a serverless platform that automatically scales to zero and charges only for request processing, making it a valid option for low-traffic containerized apps.
Related concept
Scaling to zero
Common exam traps
Common exam trap: answer the scenario, not the keyword
A common pitfall is thinking that App Engine Standard cannot scale to zero, but it actually can. Cloud Run is also valid, but both are correct for this scenario.
Detailed technical explanation
How to think about this question
Cloud Run uses a request-driven model where each revision is backed by a Knative serving layer that routes HTTP requests to containers. When no requests are received for a configurable period (default 15 minutes, up to 1 hour), the container instance is terminated and the revision scales to zero, releasing all allocated CPU and memory. This is achieved through the Knative Autoscaler, which uses a 'scale-to-zero' feature that is not available in App Engine Standard or Compute Engine autoscaling configurations.
KKey Concepts to Remember
- Scaling to zero
- Fully managed serverless
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Scaling to zero
Real-world example
How this comes up in practice
An e-commerce site experiences heavy traffic on Black Friday and near-zero traffic during off-peak weeks. Rather than provisioning permanent large VMs, the team uses auto-scaling groups that add capacity automatically under load and reduce it overnight. Questions like this test whether you understand elasticity, availability zones, and cloud compute scaling patterns.
Quick reference
Cloud Service Model Comparison
| Model | You Manage | Provider Manages | Examples |
|---|---|---|---|
| IaaS | OS, runtime, apps, data | Hardware, hypervisor, networking | EC2, Azure VMs, GCP Compute Engine |
| PaaS | Apps and data | OS, runtime, middleware, hardware | Elastic Beanstalk, Azure App Service |
| SaaS | Data and settings only | Everything else | Microsoft 365, Salesforce, Workday |
| FaaS / Serverless | Function code only | Infra, scaling, runtime | Lambda, Azure Functions, Cloud Run |
| CaaS | Containers and apps | Kubernetes, OS, hardware | EKS, AKS, GKE |
What to study next
Got this wrong? Here's your next step.
Review scaling to zero, then practise related PCD questions on the same topic to reinforce the concept.
- →
Deploying applications — study guide chapter
Learn the concepts, then practise the questions
- →
Deploying applications practice questions
Targeted practice on this topic area only
- →
All PCD questions
999 questions across all exam domains
- →
Google Professional Cloud Developer study guide
Full concept coverage aligned to exam objectives
- →
PCD practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related PCD practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Manage a Solution that Can Span Multiple Database Systems practice questions
Practise PCD questions linked to Manage a Solution that Can Span Multiple Database Systems.
Deploy Scalable and Highly Available Databases in Google Cloud practice questions
Practise PCD questions linked to Deploy Scalable and Highly Available Databases in Google Cloud.
Design Scalable and Highly Available Cloud Database Solutions practice questions
Practise PCD questions linked to Design Scalable and Highly Available Cloud Database Solutions.
Migrate Data Solutions practice questions
Practise PCD questions linked to Migrate Data Solutions.
Designing highly scalable, available, and reliable cloud-native applications practice questions
Practise PCD questions linked to Designing highly scalable, available, and reliable cloud-native applications.
Building and testing applications practice questions
Practise PCD questions linked to Building and testing applications.
Deploying applications practice questions
Practise PCD questions linked to Deploying applications.
Integrating Google Cloud services practice questions
Practise PCD questions linked to Integrating Google Cloud services.
Managing application performance monitoring practice questions
Practise PCD questions linked to Managing application performance monitoring.
PCD fundamentals practice questions
Practise PCD questions linked to PCD fundamentals.
PCD scenario practice questions
Practise PCD questions linked to PCD scenario.
PCD troubleshooting practice questions
Practise PCD questions linked to PCD troubleshooting.
Practice this exam
Start a free PCD practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this PCD question test?
Deploying applications — This question tests Deploying applications — Scaling to zero.
What is the correct answer to this question?
The correct answer is: App Engine Standard Environment. — Both App Engine Standard Environment and Cloud Run satisfy the requirements of low traffic, minimal operational overhead, and scaling to zero. App Engine Standard can scale to zero when no requests are incoming and supports Python, making it a valid choice. Cloud Run also scales to zero automatically and is fully managed, but for a simple Python web app, App Engine Standard offers even less configuration. Therefore, both options are correct.
What should I do if I get this PCD question wrong?
Review scaling to zero, then practise related PCD questions on the same topic to reinforce the concept.
What is the key concept behind this question?
Scaling to zero
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Keep practising
More PCD practice questions
- A company is deploying a microservices architecture on GKE. They need to expose a set of related microservices under a s…
- You need to monitor the CPU usage of a Compute Engine instance and trigger an alert when it exceeds 80% for 5 minutes. W…
- A Cloud Bigtable instance has a single cluster. To improve availability and read throughput, the team decides to add a s…
- A developer wants to enable IAM database authentication for Cloud SQL for PostgreSQL. Which IAM role must be granted to…
- A company is using Cloud Bigtable for a time-series workload. They want to monitor performance and identify hot spots. W…
- A company wants to run hybrid transactional/analytical processing (HTAP) workloads on a PostgreSQL-compatible database w…
Last reviewed: Jun 25, 2026
This PCD practice question is part of Courseiva's free Google Cloud certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the PCD exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.