What kind of portfolio project should a new front-end engineer build?

Your current projects are a reasonable starting point, but they sound fairly beginner-level, so I wouldn’t rely on them alone for a professional portfolio. Keep improving them if there’s room to add meaningful features, then build one larger application that demonstrates your understanding of component design, state management, responsive CSS, testing, and deployment. A simple, finished app that works well is better than an ambitious project that is incomplete.

For your portfolio site, keep the presentation clean: briefly introduce yourself, list your technical skills, feature three or four carefully selected projects, and include a short explanation of what you built and the challenges you solved. Make sure everything works on mobile, provide live demos when possible, and write useful project documentation. The site itself should support your projects rather than distract from them.

Build something genuinely useful and a little more involved than a basic tutorial project. Find an interesting public API and create a polished interface that consumes it. Add features such as search, filtering, loading and error states, responsive layouts, form validation, and accessibility. A complete project with a clear README and live demo will show much more than several tiny apps.