All posts
Red Hat Certified System Administrator (RHCSA) #15: Exam tips, time management, and patterns people get wrong
A compressed read for the moment right before you walk into the RHCSA hands-on exam. We cover the time management that runs your 2.5 hours from the easy tasks outward in dependency order, how to solve unfamiliar tasks with man pages when there is no internet, the habit of verifying tasks with a reboot, the recurring patterns that bleed points across the whole series (fstab typos, missing service enable, missing firewall reload, missing persistent SELinux settings) and how to avoid them, easily confused concept pairs, and a domain-by-domain checklist to run right before you sit. The next post, #16, is a full-scale mock exam.
Why Ads Follow You: Cookies, RTB, and Privacy
Why the running shoes you glanced at follow you across every news site — explained without code. What ad networks collect through cookies and device IDs, how the 0.2-second real-time bidding auction works, and what users can still do as third-party cookies fade and Apple ATT changes the rules.
LLM App Development #7: Embeddings and Vector Search
Embeddings turn text into vectors that carry meaning, and vector search finds similar documents using those vectors. The preparation step for RAG in the next part.
AWS Certified CloudOps Engineer - Associate (SOA-C03) #10 Domain 4-1 Networking — VPC Operations and Connectivity Troubleshooting
The tenth post of the SOA-C03 series covers VPC operations, the first topic in the networking domain (18%). It covers route tables and gateways, the difference between security groups and NACLs, NAT and VPC endpoints, peering and Transit Gateway, and where to check and in what order when connectivity fails.
Build a Manual with Docusaurus #2: Sidebar and Search — Structuring Your Documentation
When docs grow into dozens of pages, the sidebar and search are what keep readers from getting lost. We'll set up the sidebar in sidebars.js, both automatically and manually, and lay out your options for adding search in Docusaurus.
Build a Manual with Hugo #3: Writing Content — Code Blocks, Mermaid, Callouts
We cover three elements that make docs pleasant to read. From code blocks that carry filename and line highlighting, to Mermaid diagrams drawn as code, to callouts that make cautions and warnings stand out — we cover how to use each in Hextra.
Build a Manual with MkDocs #2: nav and Search — Shaping the Information Structure of Your Docs
Even as your docs grow to dozens of pages, a sidebar and search are what keep readers from getting lost. We'll design the nav directly in mkdocs.yml, turn on Material's navigation features, and enable the built-in search.
Build a Manual with Starlight #2: Sidebar and Search — Structuring Your Docs
When your docs grow to dozens of pages, the sidebar and search are key to keeping readers from getting lost. We configure the sidebar automatically and manually in Starlight, and take a look at the built-in search.
Certified Kubernetes Administrator (CKA) #25 Troubleshooting 4: Networking, DNS, RBAC, Certificate Expiry
The 25th post in the Certified Kubernetes Administrator (CKA) series. We lay out the diagnostic order to walk when service communication fails — from Endpoints all the way to NetworkPolicy — how to narrow down name-resolution failures with CoreDNS and nslookup, how to read RBAC Forbidden errors with auth can-i, and how to find and fix expired certificates with kubeadm certs check-expiration.
Certified Kubernetes Application Developer (CKAD) #20: Exam Tips, Time Management, and the Patterns People Miss
A compressed read-through to take with you right before the CKAD hands-on exam. We cover the time management for running roughly 15–20 tasks in 2 hours, a refresher on the kubectl speed setup, using imperative generators and the official docs, eight recurring patterns that leak points on the practical and how to avoid them, confusing concept pairs, and a per-domain pre-exam checklist. The next post, #21, is a full-scale hands-on mock exam.
Certified Kubernetes Security Specialist (CKS) #18: Container immutability, forensics
The eighteenth post in the Certified Kubernetes Security Specialist (CKS) series. We cover the final pieces of runtime security — container immutability and incident response. We work through YAML examples for the pattern of hardening the filesystem to read-only with readOnlyRootFilesystem and opening only the paths that need writes via emptyDir, the immutable operating model that forbids in-place changes and only swaps via redeploy, and the forensics procedure of isolating a compromised Pod with a NetworkPolicy and a node cordon, preserving evidence, and then investigating with kubectl debug.
Hardware Intermediate #2: CPU Deep Dive — Turbo, Throttling, Steal Time
The clock on the spec sheet is not a promise. Why turbo boost and thermal throttling make the clock swing, the steal time that eats away a VM's CPU, the cost of context switching, and CPU pinning — the CPU as it behaves in operations.