I recently had an interview at a taxi firm that followed this format. One two three pre-interviews followed by a day of 5 grueling 1 hour interviews. I didn't get the role. Apparently the frontend guy I had the first interview of the days five was concerned about my technical skills. I mean, I find it insulting, having worked for the last 12+ years as a developer to be told that there were "concerns about your techni…
I've done plenty of interviews, and the amount of years someone worked does not mean they are technically capable.
By chance, last week I interviewed a frontend JavaScript expert: couldn't explain 'scope', couldn't explain 'function context', didn't know what happens when setTimeout() is followed by an infinite loop ("After 10 seconds or so the browser will probably timeout the loop"). A junior cannot know everything, a senior should be able to pull a project and team.
Personal advice to you: if you are really good but cannot show it in an interview, try to land a job at companies with ex-colleagues, where they are able to vouch for your technical skills.
If a colleague that I respect vouches for someone (s)he worked with, (s)he is practically already hired.