3B Infrastructure is a free software engineering handbook in a hand-drawn style. The page explains system architecture, databases, AWS, DevOps, and VPS deployment in easy-to-understand English, and each topic has a dynamic demo for you to interact with.

Problem addressed: technical documentation is often long, dry, and hard to visualize what really happens when a request passes through the system, or when a security step is skipped on the server.

Practical examples you can look up immediately:

• Website slows down with 1,000 users at once: see demo cache, load balancer, and Auto Scaling to understand where the system is bottlenecked and how to address it in order
• Just bought a VPS: see the server being attacked without an SSH key and firewall, then revisit the same scenario after proper setup
• Database exposed to the internet: see how data is deleted and ransomed, then fix it by allowing access only to localhost
• Preparing for a system design interview: see an online store illustrated through all 4 levels of C4 diagrams
• Just started working: see a change moving from Dev, Test, Staging to Production, including how to rollback when an error occurs

Main features:

• 130 topics with dynamic demos, featuring play, pause, and step-by-step viewing buttons
• VPS guidance from buying the server to running it live, each step with specific commands and demos comparing skipped vs. correct setups
• 16 courses, from Engineering Mathematics, C, C++ to real-time Arduino, Nuvoton NUC140, and Raspberry Pi
• Software engineering course roadmap, mostly free

Who should use it: software engineering students, new programmers wanting to understand systems and DevOps, and those preparing to self-deploy products on a VPS.

How to get started: open the website on a computer or phone, no registration or installation needed, and then click Play on any diagram.

Unique point: instead of just having static diagrams, all concepts can run as demos. The project is open-source under the MIT license.

Results after learning: you will be able to draw a C4 diagram for a system, explain when to choose monolith vs. microservices, self-build a VPS with SSH key, firewall, and HTTPS, and read a pipeline from Dev through Test to Production.

Suggested roadmap for beginners: start with Database Concepts, move to System Architecture to understand cache and load balancer before learning microservices, then proceed to AWS and DevOps, and finally self-deploy on VPS. The Courses page has available steps to learn in order.