How to choose portfolio projects that prove engineering skill
Start with the job or client work you want next. A front-end portfolio project should make interaction quality obvious, an AI portfolio project should show evaluation and cost thinking, and a backend project should explain reliability, data model, and failure handling.
Strong software engineer portfolio projects have a finished product surface, a short technical write-up, and visible proof: screenshots, live URLs, code links, tests, metrics, and tradeoffs. Keep the scope tight enough that you can polish the final result.