I tried 2 flavors of a technical interview and this round was 1 hour in total.
The first was a traditional interview problem where we give the candidate a codebase and a docker image to run against. The problem itself involves using the docker image to post and get responses from but the candidate is expected to write a new helper/service in any language they choose. We ask for no agentic workflows for this but any other resource is fair game. This has been the most successful for us to find candidates and generally provides the best experience.
Our full agentic interview involves an existing fullstack typescript codebase that we give to the candidate a week or two before. The candidate is free to use any agentic workflows they want during the interview and we give them a ticket that we went to implement during the interview. I find a ton of variability in this interview and a lot of people will just take the entire ticket and one shot into Claude without prepping. This is lead to the biggest disparity in results of candidates so we stopped doing it.