Kubestronaut Challenge

From basic knowledge to Kubestronaut in two intensive months.
Below, you’ll find all insights gathered throughout the journey, adhering to the Open Knowledge principles.

This article is licensed under CC BY 4.0.

Table of Contents

Non-Kubernetes background

I began this challenge with minimal experience in both Linux and Kubernetes and none in products covered in CKS.

My core expertise lies in virtualization infrastructure and related technologies. While I had some exposure to Kubernetes through projects involving Anthos, Tanzu, and OpenShift, my role was primarily focused on deployment within VMware environments. The architectural design and surrounding components of Kubernetes were managed by dedicated Kubernetes professionals, and my understanding of their work was quite limited.

The goal of this challenge was to close that gap and ensure I could collaborate effectively with Kubernetes professionals when designing Kubernetes platforms on top of virtualization infrastructure.

Why should you attempt the Kubestronaut?

For a non-Kubernetes professional it is perfect. The exams provide clear objectives and milestones helping you stay focused and learn efficiently. You will learn a lot.

For a Kubernetes professional, it is slightly different.
You should already have all the knowledge required, however, it’s worth reviewing the certifications curriculums – especially for the CKS – to identify any gaps.
If you find some, then embarking on this journey will be valuable.
A professional, after learning the “exam skills”, should be able to pass all certifications without any issues.

Aim for Kubestronaut from the start

Commitment: If you have purchased the bundle you are stuck and have to complete it.
Optimal exams order: By taking exams in a specific order KCNA and KCSA are easier.
Price: The Kubestronaut bundle is slightly cheaper than each certification one by one.
In addition, there are frequent coupon codes – regularly posted by Sajeeva – you can easily save up to 40%.

Passing Is 70% Knowledge, 30% Exam Skills

It’s critical to understand the nature of these lab-based exams.

Are you a Kubernetes professional with deep ecosystem knowledge, working on production-critical systems? Have you worked with AKS, EKS, OpenShift? Do you have cloud infrastructure experience? Maybe you’ve built entire CI/CD pipelines and only push changes via Git?

If you answered yes to all of the above—congratulations. You’re what I’d call a complete Kubernetes professional. But here’s the catch: that’s not what’s being tested.

You will be assessed on your knowledge of Kubernetes and few related products via lab-based exams.
It is a significant amount of knowledge, but it’s quite limited compared to what is expected from a professional.
These exam are extremely time-constrained, especially the CKS, therefore, you will have to be as efficient as possible in a very short amount of time while using only core tools like Kubectl.
This isn’t reflective of working in a production environment—except during high-pressure troubleshooting when systems are down.

The 70/30 rule:

70% Knowledge – You cannot pass the CKA, CKAD, CKS without the required knowledge.
30% Exam Skills – Even a highly skilled complete Kubernetes professional may fail without the right exam skills.

What are these exam skills?

Strategy

Passing scores are 66% or 67%, which means it’s NOT necessary to complete all questions.
Aiming for 100% perfection on each question is a recipe for failure.

Two potential approaches could be:

Do only 80% of questions but ensure that they are perfect with extra testing.
Question weight also matters—doing only the easy ones won’t be enough.
Attempt 100% of questions without enough time for rigorous testing.

You need to find what strategy works well for you before the exam.
Mock exams are the only way to identify this.

I have used the strategy below:

Attempt as many questions as possible.
Measure twice cut once.
It means triple check all settings before applying.
Very basic testing to no testing at all.
If it is not possible to check easily and fast, skip testing.
Skip hopeless questions. It is better to focus on other questions.
Flag difficult and time consuming questions. Complete first the fast and easy ones.

A skilled Kubernetes professional may fail with a bad strategy.
For example, being able to reply to 90% of the questions will not help if stuck in the first question and insisting on fixing it before moving to the next. There won’t be enough time for the others even when knowing the answers.

Tactics

Master imperative commands and –dry-run=client -o yaml.
It is much faster to create or edit an object this way than building a YAML file from scratch even if it is not something that you will use in production. Even the official documentation recommends it for “Development projects”.
Use them whenever suitable during the exam.
Navigate the documentation efficiently: Know how to quickly access relevant sections in the Kubernetes documentation and any other allowed documentation during the exam.
Whether by planning keywords to search or understanding how to navigate through the menu, having a strategy will save you time.
Plan which configuration examples to copy paste. If you know what to reuse you will save a lot of time.

Exam tips

Use a LARGE screen
Same advice than for any other PSI lab exam.
I often used two terminals and the documentation when replying to one question.
READ and UNDERSTAND the instructions.
Even if time is limited, do not rush. A false start will cost you time or even points.
I have started a question by doing X and read in the next part of the instructions in a big warning box do not do X or you will lose points.
There is sometimes a last instruction below everything else. It is easy to miss it. So read the whole instruction section carefully.
Plan second attempt DURING the first
If you feel that the first attempt is doomed, don’t waste time scraping few extra points.
Instead use the remaining time to review ALL questions and identify what you know and don’t know.
Before your next attempt practice everything you know to be even faster and learn everything you don’t know.
Gain few seconds during the introduction.
During the “introduction” of the environment, as far as i understand the timer is not started but the first question is partially visible. Start to read it. Maybe you could gain 10/20 seconds and in this exam every second matters.
Gamble as a last resort.
If you have no idea how to reply and the option to gamble, take a shot. A low chance of scoring is better than a guaranteed zero.
Find tips shared by others.
E.g. 10 Mistakes that will RUIN Your CKA/CKAD Score!

Learning plan: Recommended Resources and Order

I recommend pursuing the certifications in this order CKAD – CKA-KCNA-CKS-KCSA.
It will make CKAD and KCSA easier than attempting them before CKA/CKAD and CKS respectively.
KCNA has 46% “Kubernetes Foundamentals”, which are nearly guaranteed after CKAD and CKA.
KCSA similar logic

Below are all study resources i have used, or discovered too late, and the order i recommend using them.
I have used extensively KodeKloud. It is a paid subscription but in my opinion worth it in a Kubestronaut journey primarily due to the labs.
Many resources are video-based. If you can keep up i recommend x1.5 or x2 speed and slow down in case of complex topic.

Introduction to Cloud Infrastructure Technologies (LFS151)
A MUST for the KCNA. Very good and free.
Introduction to Kubernetes (LFS158) –
Free. Maybe optional if you follow KodeKloud KCNA courses
Kubernetes and Cloud Native Essentials (LFS250)
Paid. Maybe optional if you follow KodeKloud KCNA courses
KodeKloud – DevOps Pre-Requisite Course
I should have started by this one. I have not completed it yet.
KodeKloud – Learning Linux Basics Course & Labs
KodeKloud – Docker Training Course for the Absolute Beginner
KodeKloud – Kubernetes for the Absolute Beginners
KodeKloud – Kubernetes and Cloud-Native Associate (KCNA)
I have not checked it. I was already KCNA before getting the subscription.
KodeKloud – CKA Certification Course – Certified Kubernetes Administrator
I recommend the CKA course and THEN the CKAD course. Majority of CKAD is covered in CKA course but in this way you will review a second time all CKAD topics before the exam.
KodeKloud – Kubernetes Challenges
KodeKloud – Helm for Beginners
Helm is already partially covered in the other courses, but extra training is always a nice to have.
KodeKloud – Certified Kubernetes Application Developer (CKAD)
KodeKloud – Ultimate Certified Kubernetes Application Developer (CKAD) Mock Exam Series
Killercoda – Killer Shell CKAD –
I have not used them but i assume they are as good as the CKS ones.
Killer.sh CKAD simulator – Included in the purchase of the CKAD exam.
Isovalent Network Policy Editor for Kubernetes
Play with the “standard” network policies but keep Cilium ones for a later stage.

Attempt CKAD

KodeKloud – CKA Certification Course – Certified Kubernetes Administrator
Review this course if needed
KodeKloud – Ultimate Certified Kubernetes Administrator (CKA) Mock Exam Series
Killercoda – Killer Shell CKA – I have not used them but i assume they are as good as the CKS ones.
Killer.sh CKA simulator – included in the purchase of the CKA certification. Practice both.

Attempt CKA

KodeKloud – Kubernetes and Cloud Native Security Associate (KCSA)
Security is part of the KCNA
Review LFS151

Pass the KCNA – Pass, not attempt. With the training above i don’t see how anyone could fail.

KodeKloud – Certified Kubernetes Security Specialist (CKS)
KodeKloud – Cilium Certified Associate (CCA)
It may be overkill but the CKS exam is hard, so anything that could help you understand and gain few minutes is useful.
Isovalent Network Policy Editor for Kubernetes
Practice Network policies and Cilium policies.
Cilium labs Cilium – Interactive Tutorials & Learning Labs
There are many labs, for CKS it is not needed to do all of them but at least everything related to network policies encryption and MTLS.
Read Kubernetes Networking and Cilium | Isovalent Book
KodeKloud – Istio Certified Associate (ICA)
Same idea as above, maybe overkill.
Drawback, the official exam has been updated so this course will need to be updated to use the “v1” objects and not “v1beta” for example.
KodeKloud – DevSecOps – Kubernetes DevOps & Security
It is not directly linked to the CKS but brings another perspective and complement it. It is always good to have a bigger picture. I have not completed it yet, just learned what i think could be useful for CKS.
Read the CIS Kubernetes Benchmark
YouTube – Kubernetes CKS Full Course Theory + Practice + Browser Scenarios
Warning: AppArmor is outdated on this course.
Youtube – Kubesimplify Kubernetes CKS Certification(NEW UPDATE 2025)
KodeKloud – CKS – Challenges
Unfortunately, there is no CKS Mock Exam series. It would have been very useful, it is the hardest certification.
Killercoda – Killer Shell CKS – Very good
Killer.sh – CKS – included in the purchase of the CKS certification
Sailor.sh CKS – More practice is good. I only managed to run the test with 12 questions and not the 20 planned. But in GitHub there were the 20 questions so i have just studied from there.

Attempt the CKS – Is is the hardest lab based exam that i have attempted in my life so far.

KodeKloud – Kubernetes and Cloud Native Security Associate (KCSA)
Review it one last time.

Attempt the KCSA

CKS From 51% to a Pass in 65 Hours of Training.

My first attempt at the CKS exam didn’t go as planned. It was far more difficult than I expected. I panicked early—spending too much time on one question, eventually giving up on it, and falling into a stressed mindset that affected the rest of the exam.

Lesson learned: Having a clear strategy before the exam—and sticking to it—is absolutely critical.

When all hope seemed lost, i got the idea to “Plan second attempt during the first”.

In the days that followed, I doubled down on learning:

Completed KodeKloud’s Istio, Cilium, and partially DevSecOps courses
Watched the full CKS course on YouTube
Read the CIS Kubernetes Benchmark
Read the entire Tasks section of the official Kubernetes documentation
Reviewed everything I had failed—and optimized speed on everything I already knew

Even with this preparation, I finished the second attempt after replying to all questions with just one minute remaining.
It is really a challenging exam.

Only a First Step, What Comes Next?

For those without a background in Kubernetes or Linux, achieving Kubestronaut is a strong first milestone. However i would estimate that it places someone at a 4/10* on the core Kubernetes expertise scale.

Labs are useful but do not replace real world experience.
Design skills are missing. The certifications are focused on the “what” not on the “why”.

A complete Kubernetes professional is also familiar with many technologies in the ecosystem.
The CKS is a first step in this direction, but it is not enough on its own.

Next steps:

Search for good Kubernetes design resources.
I will share finding here.
Explore various Kubernetes “distributions”
- Nutanix Kubernetes Platform – It is the next short term goal.
- OpenShift – Medium term goal.
Golden Kubestronaut?
The selection of products covers a variety of the concepts in the ecosystem.
However it seems very challenging especially the LFCS for a non-Linux background and the ICA with 75% pass mark.
KodeKloud has added a Golden Kubestronaut path recently but some courses are still in development.

*Scale used:
1-2 Basic knowledge
3-4 Junior level
5-6 Professional level
7-8 Senior level
9-10 Expert level

Timeline and total hours

13 June – Purchase Kubernetes Bundle and start to study for KCNA
19 June – KCNA
22 June – Purchase KodeKloud subscription and start to study for CKA and CKAD
Slow down during holidays
30 July – CKA
1 August – CKAD
2 August start studying KCSA and KCS
KCSA + KCS first attempt – 13 August
KCS – 25 August

Estimation total hours: 370 hours.

KCNA: 45 hours
CKA + CKAD: + 180 hours
KCSA + KCS (first attempt): + 80 hours
KCS (Second attempt): + 65 hours