Intermediate

You have metrics telling you something is slow. You have logs telling you errors happened. But which request failed? Where did the latency come from? Which service in the chain caused the timeout? This is where distributed tracing comes in. It follows individual requests as they flow through your microservices, showing you exactly what happened and where. The Observability Triangle flowchart TD subgraph observability["Complete Observability"] M["Metrics<br/>(Prometheus/Thanos)<br/>WHAT is happening"] L["Logs<br/>(Loki)<br/>WHY it happened"] T["Traces<br/>(Tempo)<br/>WHERE it happened"] end M <--> L L <--> T T <--> M G["Grafana"] --> M G --> L G --> T Metrics answer: “What is the error rate? What is the latency?” Logs answer: “What error message? What was the context?” Traces answer: “Which service? Which call? What was the path?” Together, they give you complete understanding. ...

You’ve got Prometheus for metrics. You can see what’s happening across your clusters. But when something breaks, metrics tell you that something is wrong — logs tell you why. The traditional answer is Elasticsearch. It’s powerful, flexible, and… expensive. It indexes everything, which means you pay for every byte of log data in CPU, memory, and storage. Loki takes a different approach: index labels, not content. It’s the same philosophy that makes Prometheus efficient for metrics, applied to logs. ...

People often think you need VMware, Hyper-V, or at minimum Proxmox to run a “real” hypervisor. Something with a web UI, enterprise features, the whole package. But here’s the thing: KVM with libvirt can do virtually everything those commercial hypervisors do. Live migration, memory ballooning, CPU pinning, GPU passthrough, SR-IOV, nested virtualization — it’s all there. The Linux kernel has been a production-grade hypervisor for over a decade. I run NixOS as my hypervisor. No Proxmox, no web UI, just declarative Nix configs and virsh. Let me show you what’s possible. ...

I’ve run both Arch and NixOS as my daily driver workstation. Not in VMs, not as a weekend experiment — as my actual work machine where I do professional DevOps/platform engineering work, and as my personal machine where I do everything else. Both are excellent. Both have serious trade-offs. And the “best” choice depends heavily on your life situation and how much time you have for system maintenance. Here’s the thing: I have kids now. The days of spending a Saturday afternoon debugging a broken Xorg config are gone. My system needs to work, reliably, every time I open the laptop. But I’ve also learned that Arch’s “instability” is largely a skill issue — with the right practices, Arch can be just as reliable as NixOS. ...

I spend my evenings doing Hack The Box challenges and CTF competitions. Not because I want to become a pentester — I’m happy in platform engineering. But because the skills I learn there make me significantly better at my day job. This isn’t obvious at first. What does pwning a vulnerable web app have to do with running Kubernetes clusters? More than you’d think. Forensics and offensive security train you to think about systems differently. You learn to investigate, to trace, to understand what’s actually happening rather than what should be happening. And that mindset — plus the tooling — is exactly what you need when debugging production issues at 3 AM. ...