Years of 𝗗𝗲𝘃𝗢𝗽𝘀 knowledge condensed into 12 concepts. 𝗟𝗲𝗮𝗿𝗻 𝘁𝗵𝗲𝗺 𝗶𝗻 𝘁𝗵𝗶𝘀 𝗼𝗿𝗱𝗲𝗿 𝗮𝗻𝗱 𝗲𝘃𝗲𝗿𝘆𝘁𝗵𝗶𝗻𝗴 𝗰𝗹𝗶𝗰𝗸𝘀. 1: 𝗟𝗶𝗻𝘂𝘅 The foundation of much of modern infrastructure. Learn the filesystem, processes, permissions, shell commands and how to troubleshoot a running machine. 2: 𝗡𝗲𝘁𝘄𝗼𝗿𝗸𝗶𝗻𝗴 Understand IP addresses, DNS, ports, TCP, HTTP and firewalls. Before debugging an application, you need to understand how machines communicate. 3: 𝗚𝗶𝘁 Track every code change, collaborate with other developers and roll back mistakes. Infrastructure and application code both benefit from version control. 4: 𝗦𝗰𝗿𝗶𝗽𝘁𝗶𝗻𝗴 Automate repetitive work with Bash or Python. If you keep doing something manually, there's probably a way to automate it. 5: 𝗖𝗹𝗼𝘂𝗱 𝗖𝗼𝗺𝗽𝘂𝘁𝗶𝗻𝗴 Learn how compute, storage, networking and managed services work on AWS, Azure or GCP. You don't need to master all three. 6: 𝗗𝗼𝗰𝗸𝗲𝗿 Package applications and their dependencies into containers. Build consistent environments from development to production. 7: 𝗖𝗜/𝗖𝗗 Automate builds, tests and deployments. Move code from a developer's machine to production through a repeatable pipeline. 8: 𝗜𝗻𝗳𝗿𝗮𝘀𝘁𝗿𝘂𝗰𝘁𝘂𝗿𝗲 𝗮𝘀 𝗖𝗼𝗱𝗲 Define infrastructure in version-controlled files instead of clicking through dashboards. Terraform is one popular tool for this. 9: 𝗞𝘂𝗯𝗲𝗿𝗻𝗲𝘁𝗲𝘀 Orchestrate containers across machines. Manage deployments, service discovery, scaling and recovery when containers fail. 10: 𝗦𝗲𝗰𝗿𝗲𝘁𝘀 & 𝗦𝗲𝗰𝘂𝗿𝗶𝘁𝘆 Manage credentials, permissions, network access and sensitive configuration safely. Never let convenience become a security vulnerability. 11: 𝗢𝗯𝘀𝗲𝗿𝘃𝗮𝗯𝗶𝗹𝗶𝘁𝘆 Use logs, metrics, traces and alerts to detect problems, investigate incidents and understand infrastructure performance. 12: 𝗦𝗥𝗘 (𝗦𝗶𝘁𝗲 𝗥𝗲𝗹𝗶𝗮𝗯𝗶𝗹𝗶𝘁𝘆 𝗘𝗻𝗴𝗶𝗻𝗲𝗲𝗿𝗶𝗻𝗴) Keep systems reliable through automation, incident response, capacity planning, service-level objectives and learning from failures. DevOps isn't about memorizing tools. It's about building a reliable, repeatable path from code to production. Learn the concepts first. The tools will make much more sense afterward.