Demonstrating capability.
WHAT A PORTFOLIO DEMONSTRATES
That you can actually build things.
WHY THAT MATTERS
Claims are cheap. Working software is not.
WHAT TO BUILD
Something you actually want to exist Something solving a real problem Something someone else uses, ideally
WHAT NOT TO BUILD
Tutorial projects everyone has built.
WHY
They demonstrate following instructions.
WHAT TO INCLUDE FOR EACH PROJECT
What problem it solves What you built it with, and why What was difficult What you would do differently
WHY THAT LAST POINT
It demonstrates judgement, which distinguishes experience.
WHAT TO MAKE AVAILABLE
The code, readable and documented A working version, where practical
WHAT TO INCLUDE IN THE CODE
A readme explaining setup Tests Clear structure
WHY
Reviewers look at how you write, not only what you built.
WHAT TO PREFER
A few projects, finished and explained, over many abandoned ones.
WHAT TO KEEP CURRENT
The code, and the deployed version.