Where we can really save time is focusing on the matching process of candidates to companies. Interviewing is tiring and we find candidates often stop talking to companies they were initially excited about because they're exhausted from interviewing (usually after 4 on sites) and just want to accept an offer
We wrote before about how much hiring preferences vary across YC companies (http://blog.triplebyte.com/who-y-combinator-companies-want). By using data we get from the Triplebyte interview, we can send you to the companies where you've the strongest likelihood of passing the technical onsite. The result is getting the best set of offers to choose from, rather than picking from what's available before interview burnout sets in.
Just focusing on interviewing time, if you're talking to 3 or more companies that's approximately 3 hours of technical phone screens (usually repeating similar problems). With Triplebyte, you interview for 2.5 hours and save 3 (or more as you talk with more companies).
You can schedule the interview by first taking a simple quiz for like 15 minutes and then selecting from a calendar, you don't need to negotiate with a person, go back and forth, etc.