For me, my emotions go through three stages:
1. First, a bit of concern, since this means a certain level of competition.
2. Then, I feel happy, as the fact that others are doing something similar means the demand is more likely to be appreciated by users.
3. Finally, I become calm, realizing that today's tasks still need to be finished.. haha.
As for action, I would try to reach out to people working on these big companies' projects to see if there are any collaboration opportunities or just to make new connections.
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