How can I choose an impactful project?

When you say you “choose” the project, it makes me think that you’re selecting among various options. However, for a senior+ engineer, the best projects are ones where you played a significant role in defining the milestones and outcomes of the project. You want to be the one defining the project rather than choosing something that the product manager handed to you.

Once you’re comfortable with having a more active role in what you’re working on, a few recommendations:

• Start with the business impact, then work backward into the engineering work. You don’t get bonus points for making something technically interesting. Start with tackling the problem first, and usually the technically interesting part comes in making it scale or apply across multiple teams.
• Go beyond your eng manager and product manager to validate the business impact. There are always risks associated with any project, so it’s your job to mitigate those and be smart about where you invest your time. A big part of that is talking to more people.
• In addition to talking to your immediate team, get feedback from TLs and managers on adjacent teams. This lets you collect their feedback/concerns, but also (importantly) makes them aware of what you’re doing, and the benefit from your work.