For collaborative interface design, especially within product teams, choose Figma. Its real-time multiplayer capabilities and robust support for design systems make it ideal for achieving polished results and maintaining a cohesive design workflow. However, be cautious if you're part of a large team, as editor seat costs can add up, and it may struggle on lower-end machines with heavier files.
If you need a lightweight, low-fidelity solution for brainstorming or quick sketches, Excalidraw is your best bet. Its hand-drawn aesthetic fosters a creative environment and allows for offline work, catering perfectly to developers or teams looking to ideate rapidly. However, if you require high-quality visuals or a comprehensive design tool, Excalidraw won’t meet those needs, and Figma would be the better option.