The problem is that coding challenges are OK if you are hiring for an entry level position and need to make sure that the fresh grad can actually write some code at all (surprising amount of them does not).
However, what exactly are you hoping to achieve with this when hiring a senior engineer who is likely to have 10+ years of experience in the field? With verifiable references?
You are only wasting everyone's time. Sorry but I am really not going to spend a month preparing for a single interview where I have no guarantee of neither an offer and not even knowledge of the team/project I would be working on (Google recruiter calling me seriously thought that this is normal - you apply "blind" and only after passing through their hiring "torture test" of 7 or how many interview rounds you get told which position may be "the best" for you. I said "No, thank you" and hung up.)
The issue with this is that you are both testing the wrong skills (senior engineer really shouldn't be doing basic algorithms but system design, leading teams and managing projects!) and that this is "senior engineer" position is likely senior only in name because the recruiters want to attract more competent people. In reality it is an entry level job ...
However, what exactly are you hoping to achieve with this when hiring a senior engineer who is likely to have 10+ years of experience in the field? With verifiable references?
You are only wasting everyone's time. Sorry but I am really not going to spend a month preparing for a single interview where I have no guarantee of neither an offer and not even knowledge of the team/project I would be working on (Google recruiter calling me seriously thought that this is normal - you apply "blind" and only after passing through their hiring "torture test" of 7 or how many interview rounds you get told which position may be "the best" for you. I said "No, thank you" and hung up.)
The issue with this is that you are both testing the wrong skills (senior engineer really shouldn't be doing basic algorithms but system design, leading teams and managing projects!) and that this is "senior engineer" position is likely senior only in name because the recruiters want to attract more competent people. In reality it is an entry level job ...