DevOps
Containers, networking, and the infrastructure primitives behind reliable deployments. Ordered from foundational to advanced, 35 docs in this category.
Docs in DevOps
AWS Organizations & Account Structure
How AWS Organizations, organizational units, and the AWS account itself form the real isolation boundary, and why that structure - not any single resource - is where governance and billing actually happen.
Azure Fundamentals
How Azure organizes resources through management groups, subscriptions, and resource groups, and why that hierarchy, not the resources themselves, is where most governance actually happens.
Bash Fundamentals
The scripting layer built on top of the shell - variables, conditionals, loops, and functions - and the quoting and exit-status habits that separate a script that looks right from one that fails safely.
Cloud Service Models
What actually distinguishes IaaS, PaaS, and SaaS, why the boundary is "who manages what," and how the shared responsibility model determines what you're on the hook for at each layer.
Docker Fundamentals
How images, containers, volumes, and networks fit together in Docker's runtime model, and the mental shift from "installing software" to "running a packaged image" that trips up newcomers.
Git Fundamentals
How the working directory, staging area, and commit history actually relate to each other, and why understanding that three-stage model makes branching, rebasing, and undoing changes stop feeling arbitrary.
Linux Filesystem Hierarchy & Permissions
Why /etc, /var, /usr, and /opt exist as separate, standardized directories under the Filesystem Hierarchy Standard, and how chmod's octal mode and umask actually decide a new file's permissions.
Linux Fundamentals
The core command-line building blocks - navigation, permissions, processes, networking, and services - that every other Linux topic on this site (filesystem hierarchy, storage, users, networking) assumes you already have.
AWS CloudWatch & CloudTrail
How CloudWatch metrics, logs, and alarms fit together with CloudTrail's audit trail, and why CloudTrail answers "who did what" while CloudWatch answers "what is the system doing."
AWS Compute
How EC2, Lambda, ECS, and EKS trade control for convenience differently, and how to actually choose between them instead of defaulting to whichever one you already know.
AWS IAM
How IAM users, roles, and policies control access in AWS, why roles with temporary credentials are preferred over long-lived access keys, and how policy evaluation actually decides allow versus deny.
AWS Storage
How S3, EBS, and EFS fit different access patterns, what S3 storage classes actually trade off, and why durability and availability are two different numbers.
AWS VPC Networking
How Amazon VPC, subnets, security groups, and network ACLs control traffic in AWS, and why security groups (stateful, instance-level) and network ACLs (stateless, subnet-level) are not interchangeable.
Azure Active Directory (Entra ID)
How Entra ID identity, app registrations, and role-based access control fit together, and why it governs both human sign-in and workload-to-workload authentication.
Azure Compute
How Virtual Machines, App Service, and AKS trade control for convenience differently, and how to actually pick between them instead of defaulting to whichever one you already know.
Azure Monitor
How Azure Monitor, Log Analytics, and Application Insights fit together as one platform, and why KQL, not a dashboard, is where real incident investigation happens.
Azure Networking
How Virtual Networks, subnets, and Network Security Groups control traffic in Azure, and how VNet peering differs from a VPN gateway for connecting networks together.
Azure Storage
How Blob, File, and Disk storage in Azure fit different access patterns, what redundancy options (LRS, ZRS, GRS) actually protect against, and why access tiers change cost, not durability.
CI/CD Pipelines
What continuous integration and continuous delivery actually automate, how a pipeline stage graph is structured, and why fast feedback loops matter more than pipeline complexity.
Cloud Cost Optimization
Why idle and over-provisioned resources, not raw usage, are where most cloud spend actually leaks, and the concrete levers (rightsizing, commitment discounts, autoscaling) that address it.
Cloud IAM Fundamentals
How identity, roles, and policies fit together across cloud providers, why least-privilege is a discipline rather than a one-time setup, and the difference between authentication and authorization.
Cloud Networking Fundamentals
How virtual private clouds, subnets, and security groups model network isolation in the cloud, and why "public" vs "private" subnet is a routing decision, not a labeling one.
GitOps Principles
Why treating Git as the single source of truth for cluster state, instead of running kubectl/terraform apply by hand, changes how deployments, rollbacks, and audits actually work.
Linux Logging & Monitoring with journald
Why journald's default "auto" storage mode can quietly discard logs across a reboot on a fresh system, and how journalctl's unit and priority filters actually narrow down a live incident.
Linux Networking
How ip and ss replaced ifconfig and netstat as the modern tools for interfaces and sockets, what TCP socket states like LISTEN and TIME-WAIT actually mean, and how nftables organizes firewall rules into tables and chains.
Linux Process Management & systemd
Why SIGKILL can't be caught or ignored the way SIGTERM can, how systemd's Type= actually decides when a service counts as "started," and the difference between the ps command's BSD and UNIX option styles.
Linux Storage & LVM
How physical volumes, volume groups, and logical volumes let LVM pool multiple disks and resize storage without repartitioning, and what mount and /etc/fstab actually do to attach a filesystem to the directory tree.
Linux Users, Groups & sudo
How /etc/passwd and /etc/shadow split identity from password storage, why a UID (not a username) is what the kernel actually checks, and how a sudoers rule's who/where/as-whom/what structure grants privileges.
Observability Fundamentals
How logs, metrics, and traces answer different questions, why "we have monitoring" isn't the same as being able to debug an incident, and the cardinality trap that breaks metrics systems.
Platform Engineering Fundamentals
What an internal developer platform actually is, why "golden paths" beat unlimited flexibility, and how platform engineering differs from just having a good DevOps team.
Secure CI/CD Pipelines
How SAST, dependency (SCA) scanning, and DAST fit into a build pipeline as automated gates, and why failing the build on a real finding is what actually makes "shift-left" more than a slogan.
Terraform Basics
How Terraform's declarative state model, providers, and plan/apply workflow let infrastructure be versioned and reviewed like code, and the state pitfalls that trip up most teams.
Docker Networking
How Docker's bridge, host, and overlay network drivers work, how container DNS resolution happens, and the port-publishing model that trips up most beginners.
Kubernetes Fundamentals
How Pods, Deployments, and Services fit together, what the control loop actually does, and why Kubernetes networking confuses people coming straight from Docker Compose.
Service Mesh Basics
What a sidecar proxy actually intercepts, why service meshes exist once you already have Kubernetes Services, and the mTLS/observability/traffic-shaping capabilities that justify the added complexity.