I've received an ARPA-E award. So a similar process and competition level.
First you submit a 5 page concept paper, and if that's acceptable you write a 20 page full proposal (answering the Heielmeier Catechism in detail[0]). If you're selected (around 1-5% acceptance rates) you go through a contracting process--overall it takes about 1 year from initial concept paper to final contract.
Once everything's signed you're executing on a 2-3 year and $1-5 million project where you have to hit technical milestones each quarter. And if you're in the top 10% of projects that were funded by the agency that year you can except follow-on funding at about the same level.
This![0]
[0] https://beta.sam.gov/opp/a6d0788057414e2c8fd6bdf45e3fd21d/vi...
[PDF¹] https://www.darpa.mil/attachments/CCUProposersDayFAQ%20v15.p...
[PDF²] https://www.darpa.mil/attachments/CCUProposersDayBriefv7.pdf
[PDF³] https://www.darpa.mil/attachments/HR001121S0024-Amendment-01...