It proved to be invaluable.

Meaning

The experience was extremely useful or beneficial.

Examples

• John: Was the training course helpful?
• Alice: Yes, immensely! <b>It proved to be invaluable</b> in my new role.
• John: I'm glad to hear that! The feedback is important.
• Alice: Absolutely. The new skills I gained <b>proved to be invaluable</b>. It helped me a lot!