Lessons

File system, permissions, processes, scripts, and real incidents: theory plus browser-based Linux.

OSI, IP addresses and ports, DNS, HTTP, troubleshooting network problems.

Commits, branches, merge vs. rebase, and conflicts: what you need on the job.

Docker and Compose: images, networking, volumes, environment variables, registries.

Ansible and Infrastructure as Code: the agentless model, idempotency, playbooks, roles, IaC.

Team methodologies and continuous delivery: Agile/Kanban, pipelines, delivery vs. deployment, GitLab CI, rollout strategies, and patterns.

YAML, cluster architecture, Pod, Deployment, Service: from basic objects to debugging real incidents.

Metrics, logs, traces: how to see what's happening in production without logging into every server.

Backups, secrets, and patterns for reliable services: graceful shutdown, health checks, resilience to failures.

Databases, caching, and queues: Postgres, migrations, connection pools, Redis, message queues. MLOps: maturity levels, MLflow, data lakes.

Object storage and cloud service models: what to use as a service and what to run yourself.