Linux

Cheatsheet: grep, sed, awk, jq, common pipelines.

Cheatsheet: tmux + screen + bindings + config.

Cheatsheet: modes, motions, search/replace, buffers, plugins.

Cheatsheet: common git workflows, recovery, hooks, configs.

Cheatsheet: ansible CLI, playbooks, roles, modules, vault.

Cheatsheet: SSH, firewall, fail2ban, auditd, sysctl, AppArmor.

Cheatsheet: perf tools, sysctl, eBPF, network tuning.

Cheatsheet: rsync, restic, borg, ZFS/btrfs snapshots, S3.

Cheatsheet: strace, ltrace, gdb, perf, core, dmesg, eBPF.

Cheatsheet: end-to-end server setup with security, monitoring, automation.