You worked on a team project and want to add it to your portfolio. The project had several contributors, so a list of everything the product does will not tell a reader what you built.
Start with the shared goal, then describe your own part and give the reader something they can inspect.
A small example
Imagine a team built an online shop. One developer worked on the delivery-address form. If that was your actual contribution, you could write:
Our team built an online shop. I added a check for an empty delivery address and a message explaining what the customer needs to enter. The screenshot shows the message after submitting an empty form.
This is a fictional example. Adapt the structure to work you actually did. If someone else designed the interaction or reviewed the change, you can say so. Teamwork is useful context.
Choose evidence you can share
A public pull request can show a specific change and the discussion around it. A screenshot or demo can show the result. Check that the link is accessible to your reader and that you have permission to share it.
For confidential projects, describe an approved, anonymized version of the problem or create a separate example. Avoid publishing customer information or private code. A sample is useful, but label it as a sample rather than presenting it as production evidence.
What helps you explain your contribution when several people worked on the same feature?