I have mentioned this before. The best interview I had as a candidate was - they gave me access to their codebase, explained an actual relatively small bug, asked me to fix it and left me alone (I was seated among their devs, they were minding their business, I was minding my own). I think it took me half hour or so (can't remember the exact time, it was a few years ago). I fixed it, they asked me to explain how I found the bug/fixed, they made an offer.
No talking (other than me showing them how I fixed it). No bullshit questions like "where do you see yourself in 5 years" or "talk to us about your strengths" etc.
Second best - they asked me to design and write pseudo code for a simple system. Don't worry about syntax, but make sure to follow good design practices, within reason. Gave me a pen and notepad and left me alone for an hour. I wrote it, explained my thought process, they made an offer.
Then I had shitty interviews - one very large, very famous insurance company - they had 5 rounds of interviews back to back, for a normal developer role, lol. Asked me about some obscure options for grep etc. It was an exercise in them showing off their skills (more like their memory of Linux commands) than learning about my skillset. I couldn't wait to get the hell out of that building.
Of course interviews can't be light when you are hiring for highly technical, high critical positions (like security, for example). But for most software dev positions, the formats above are very efficient. Most software devs are writing "glue" code, not rewriting some mission critical real time OS.