The Software Development Life Cycle (SDLC)
SDLC (Software Development Life Cycle) is the mandatory sequence of 7 phases every software project passes through: idea -> requirements -> design -> build -> test -> deploy -> maintain. Why: this is your "zero to the last comma" path compressed into one line — your whole roadmap is this cycle unrolled, and Phase 14 is its execution by your own hand. When: starting any new project, feature, or even a bug fix ("which phase of the cycle am I in"); diagnosing any "it fell through" — almost always a phase got skipped. How: every phase has an INPUT (what it receives from the previous one), an OUTPUT (what it hands to the next), and a "done" criterion. Where: at every scale, from a 100-line script to Samevian — only the "thickness" of the phases differs. Who: every role from lesson 1 lives inside its own phase of the cycle — UI/UX in design, QA in testing, DevOps in deployment.