I recently passed the Certified Kubernetes Security Specialist (CKS) certification — on my third attempt. This is my debrief: what I studied, what the exam was actually like, and what I wish I’d known going in.

The Preparation

CKA first

You need the CKA before you can sit the CKS. I completed it in January, drawing on my experience as an Azure platform engineer maintaining AKS clusters. My study approach:

  • Mumshad’s CKA course on Udemy with KodeKloud exercises
  • Killer.Sh exam simulator practice sessions
  • Progressive skill-building through hands-on exercises

I passed with 89% on my first attempt using this method.

Studying for CKS

For the CKS I used the same general strategy:

  • KillerShell YouTube course (11 hours)
  • KodeKloud course with practical exercises
  • Killercoda free exercises
  • Killer.Sh exam simulator

The Exam

First attempt: 57% — Failed

Despite confident preparation and strong practice scores, the real exam proved significantly harder than any practice test. I encountered scenarios not fully covered in training materials — Docker configuration nuances that differed from course expectations, for example.

Second attempt: 66% — Failed by 1%

After a month focused on theory I retook it. I missed the 67% passing threshold by a single point. That one hurts.

Third attempt: 90% — Passed

I booked immediately after the second failure and changed strategy: instead of more practice exams, I drilled into specific technical details. I spun up VMs to work directly with Falco, Cilium, and other tools. Hands-on experimentation with the actual tools was the missing piece.

The Mental Side

I significantly underestimated the psychological component. Self-doubt during preparation and after two failures nearly derailed me. Learning to treat failure as information — rather than a verdict — was what ultimately made the difference.

Missing by 1% could have crushed me. Instead I booked the third attempt the same day.

Key Takeaways

Be prepared to fail. Plan for multiple attempts from the start. Booking immediately after a failure eliminates procrastination.

Practice exams don’t reflect real difficulty. Unlike CKA prep materials, CKS practice tests are noticeably easier than the actual exam. Don’t let a high practice score make you overconfident.

Time management is critical. You get 15–20 questions in 120 minutes. Flag difficult questions and keep moving — don’t let one question eat your time budget.

Hands-on beats courses. Building actual clusters and working directly with the security tools (Falco rules, Cilium policies, Docker hardening) surpasses any course-based learning. If you haven’t used the tool with your own hands, you’re not ready.

Confidence matters. Mental resilience and belief in your ability to problem-solve under pressure significantly impact your score. This isn’t soft advice — it’s practical.

Resources

The CKS pushed both my technical and mental limits. It was worth it. If you’re on this journey — keep going.