It's a great way to weed out the junior devs that cheated their way through school (or are too dumb to figure it out via stackoverflow) and the senior devs that haven't actually done any real programming in a long time.
An engineer at our competitor got laid off and my PM found out and hired the guy to do FPGA work. My PM knew the guy through some contracts we had with the competitor and assumed he was an expert in the field. Turns out the guy was more of middleman between program management and the engineers so while he could talk about the work, he hadn't really done it in like 10 years. My PM got the hiring expedited and since we don't really do interview tests in our industry, the guy was now on our team before anyone could ask any pertinent questions.
Long story short, the FPGA team starts assigning him work but it's taking way too long and he's asking for more documentation and for help on things that he definitely would have worked on in his supposed previous job. Eventually we all figure out that he kinda overstated how fresh his skills are and we transition him to a sort of documentation role so he wasn't burning hours on things he just couldn't handle. While he was perfectly capable of doing that kind of work, it involved a lot of insight to our design so it took him a while to get onboarded to the system and able to properly describe the design. Eventually he was doing good work and got the project to the point where he wasn't needed but he left a bad taste in everyone's mouth. We could have hired two junior engineers to do the work he was doing for the same price and probably gotten it done much faster. After the guy transfered over to another project, we reamed out our PM about his hiring decision and begged him to give us some input next time. Of course, due to the waste of money from the last guy, the functional managers stopped taking hiring inputs from our project and would just assign whoever the fuck they thought we needed despite the kind of roles we actually needed.