We built something that we wish existed when we started our IT careers: a complete, structured, free library of professional cheat sheets and guides that covers every major technology at every skill level. No paywalls. No "premium tier." No bait-and-switch.
The Dargslan Cheat Sheet Library contains 121 professional PDF guides organized across 4 skill levels, covering 40+ technologies. Whether you are opening a terminal for the first time or tuning a Kubernetes cluster at scale, there is a guide here for you.
Library Overview
| Tier | Count | Purpose | Best For |
|---|---|---|---|
| Quick Reference | 41 sheets | Single-page command lookup | Daily work, printing, team sharing |
| Beginner's Guide | 40 guides | Learn from scratch, step-by-step | New to a technology, career starters |
| Intermediate Guide | 20 guides | Production patterns & best practices | Working professionals, job preparation |
| Advanced Guide | 20 guides | Expert internals & architecture | Senior engineers, architects, leads |
Quick Reference Collection — 41 Sheets
Our quick reference cheat sheets are precision tools: one-page PDFs with the most essential commands organized for instant lookup. Print them, pin them next to your monitor, or keep them open as a digital reference.
Read the full Quick Reference article →
What's Included
Linux & Systems: Linux Commands · File Permissions · Bash Scripting · Vim/Nano · SSH · Systemd
Containers & Cloud: Docker · Docker Compose · kubectl · K8s YAML · Helm · AWS CLI · Azure CLI · Terraform
Databases: PostgreSQL · MySQL · SQL · MongoDB · Redis · Elasticsearch
Languages: Python · JavaScript · TypeScript · Go · Rust · Java · PHP · Ruby · C/C++ · Node.js · HTML/CSS
DevOps & Tools: Git · GitHub Actions · Jenkins · Ansible · Nginx · Apache · PowerShell · Regex · Networking · Kafka
Beginner's Guide Collection — 40 Guides
Starting a new technology is overwhelming. Our beginner guides solve this by providing structured, step-by-step learning that assumes no prior knowledge. Each guide takes you from "what is this?" to "I can do real work with this."
Read the full Beginner's Guide article →
Highlights
- 40 technologies covered — every topic from the quick reference collection also has a beginner guide
- Zero prerequisites — start from absolute scratch
- Practical examples — real commands, real output, real scenarios
- Learning paths included — know exactly what to study next
Recommended Starting Points
| Career Goal | Start With |
|---|---|
| System Administrator | Linux → Bash → Networking |
| DevOps Engineer | Docker → Kubernetes → Terraform |
| Backend Developer | Python → Git → PostgreSQL |
| Cloud Engineer | AWS → Terraform → Ansible |
Intermediate Guide Collection — 20 Guides
The intermediate collection bridges the gap between "it works" and "it works in production." These guides teach you the patterns, practices, and techniques that professional engineers rely on daily.
Read the full Intermediate Guide article →
Key Topics at This Level
- Performance optimization — PostgreSQL query tuning, Docker layer caching, Nginx caching strategies
- Security hardening — SSH key management, Kubernetes RBAC, Linux ACLs
- Production patterns — Docker multi-stage builds, Terraform modules, Git branching strategies
- Debugging mastery — systematic log analysis, query EXPLAIN plans, network troubleshooting
Available Technologies
Linux · Permissions · Bash · Vim · SSH · Docker · Compose · K8s · AWS · Azure · Terraform · Ansible · Nginx · PostgreSQL · MySQL · Python · Git · PowerShell · Regex · Networking
Advanced Guide Collection — 20 Guides
For senior engineers, architects, and technical leads. The advanced collection covers system internals, architecture patterns, and expert-level techniques that are rarely found in free resources anywhere on the web.
Read the full Advanced Guide article →
What Sets These Apart
- Kernel-level Linux tuning — sysctl, cgroups v2, eBPF, namespaces
- Kubernetes operators — custom controllers, admission webhooks, service mesh
- Database internals — PostgreSQL WAL, InnoDB buffer pool, replication deep dives
- Security architecture — SELinux/AppArmor policies, zero-trust networking, certificate authorities
- Language internals — Python metaclasses, Bash co-processes, Vim plugin development
Available Technologies
Linux · Permissions · Bash · Vim · SSH · Docker · Compose · K8s · AWS · Azure · Terraform · Ansible · Nginx · PostgreSQL · MySQL · Python · Git · PowerShell · Regex · Networking
How to Use This Library
For Individual Learners
- Pick your technology — choose based on your job, career goal, or curiosity
- Start at your level — no shame in starting at beginner, no need to if you are experienced
- Progress through tiers — beginner → intermediate → advanced → quick reference for daily use
- Practice between tiers — spend time applying what you learned before moving up
For Team Leads & Managers
- Onboarding — create custom learning paths by combining relevant beginner guides
- Skill assessments — use intermediate guides as benchmarks for professional growth
- Team references — distribute quick references for your team's core technologies
- Knowledge sharing — advanced guides spark great brown bag / lunch-and-learn topics
For Career Changers
If you are transitioning into IT, start with these beginner guides in order:
- Linux — the foundation everything runs on
- Git — version control is non-negotiable
- Python or JavaScript — your first programming language
- SQL — every application needs a database
- Docker — modern deployment is container-based
- Networking — understand how systems communicate
Technology Coverage Map
| Technology | Quick Ref | Beginner | Intermediate | Advanced |
|---|---|---|---|---|
| Linux | ✓ | ✓ | ✓ | ✓ |
| Linux Permissions | ✓ | ✓ | ✓ | ✓ |
| Bash Scripting | ✓ | ✓ | ✓ | ✓ |
| Vim/Nano | ✓ | ✓ | ✓ | ✓ |
| SSH | ✓ | ✓ | ✓ | ✓ |
| Docker | ✓ | ✓ | ✓ | ✓ |
| Docker Compose | ✓ | ✓ | ✓ | ✓ |
| Kubernetes | ✓ | ✓ | ✓ | ✓ |
| AWS CLI | ✓ | ✓ | ✓ | ✓ |
| Azure CLI | ✓ | ✓ | ✓ | ✓ |
| Terraform | ✓ | ✓ | ✓ | ✓ |
| Ansible | ✓ | ✓ | ✓ | ✓ |
| Nginx | ✓ | ✓ | ✓ | ✓ |
| PostgreSQL | ✓ | ✓ | ✓ | ✓ |
| MySQL | ✓ | ✓ | ✓ | ✓ |
| Python | ✓ | ✓ | ✓ | ✓ |
| Git | ✓ | ✓ | ✓ | ✓ |
| PowerShell | ✓ | ✓ | ✓ | ✓ |
| Regex | ✓ | ✓ | ✓ | ✓ |
| Networking | ✓ | ✓ | ✓ | ✓ |
| JavaScript | ✓ | ✓ | ||
| TypeScript | ✓ | ✓ | ||
| Go | ✓ | ✓ | ||
| Rust | ✓ | ✓ | ||
| Java | ✓ | ✓ | ||
| PHP | ✓ | ✓ | ||
| Ruby | ✓ | ✓ | ||
| C/C++ | ✓ | ✓ | ||
| Node.js | ✓ | ✓ | ||
| HTML/CSS | ✓ | ✓ | ||
| Helm | ✓ | ✓ | ||
| MongoDB | ✓ | ✓ | ||
| Redis | ✓ | ✓ | ||
| SQL | ✓ | ✓ | ||
| Elasticsearch | ✓ | ✓ | ||
| GitHub Actions | ✓ | ✓ | ||
| Jenkins | ✓ | ✓ | ||
| Apache HTTPD | ✓ | ✓ | ||
| Systemd | ✓ | ✓ | ||
| Kafka | ✓ | ✓ |
Why We Built This
We are a team of IT professionals who spent years collecting bookmarks, saving Stack Overflow answers, and building personal wikis. We realized that thousands of others were doing the same thing. The knowledge exists — it is just scattered across hundreds of blog posts, documentation pages, and forum threads.
The Dargslan Cheat Sheet Library brings it all together into one organized, professionally designed, always-available resource. And we keep it free because we believe that access to knowledge should not depend on your employer's training budget.
What's Next
We continuously expand the library. Technologies currently in development:
- Prometheus & Grafana — monitoring and observability
- ArgoCD — GitOps continuous delivery
- Istio — service mesh for Kubernetes
- Rust Advanced Guide — systems programming mastery
- Go Intermediate & Advanced — cloud-native development
Subscribe to our newsletter when you download any guide, and we will notify you when new resources are available.
Start Browsing
Visit the Cheat Sheet Library →
Pick any technology, choose your level, and start learning. All 121 guides are waiting for you — completely free.
Frequently Asked Questions
Are all 121 guides really free?
Yes. Every single one. We ask for your email so we can notify you about new guides. You can unsubscribe at any time.
Can I download all guides at once?
Yes! We offer bundle downloads: you can download all quick references, all beginner guides, all intermediate guides, or all advanced guides as a single ZIP file from the library page.
How are these different from official documentation?
Official docs are comprehensive reference manuals. Our guides are curated learning paths — we selected the most important concepts and organized them for efficient learning, with practical examples for every topic.
Can I share these with my company or university?
Absolutely. Share them freely with colleagues, students, and team members.
Will you add more technologies?
Yes. We add new guides regularly. Sign up for our newsletter to be notified of new additions.
