Chapter Two

The Software Development Life Cycle

Software doesn't leap from idea to finished in one move — it travels through a repeatable set of stages, and it keeps living long after launch. This chapter lays out that whole journey, names its phases, explains why catching mistakes early saves so much, and formally introduces the team you'll follow for the rest of the book.

4 topics

If the first chapter answered "what is software development?", this one answers "how does it actually unfold?" The answer has a name — the software development life cycle, almost always shortened to SDLC — and it's the map the entire rest of this course hangs on.

Four topics build that map. First, why software has a lifecycle at all, and why most of a system's life happens after it launches. Then the eight phases that lifecycle is usually drawn as — a preview of every chapter ahead. Then one of the most important ideas in the whole field: why a mistake gets dramatically more expensive the later it's caught. And finally, the different shapes the phases can take, plus a proper introduction to the Cadence team.

The lifecycle is a loop, not a finish line
Plan & gather requirements
decide what to build and why
Design & build
shape it, then write it
Test & release
prove it works, then ship it
Operate, maintain & loop back
run it, learn, and start the next round

Topics in This Chapter