I applied through an employee referral. The process took 3 weeks.

Nubank's selection process is very biased. The process starts with a take-home exercise, it's not difficult, but even if your code runs and gives the expected output you can still be eliminated from the selection because it's biased. They select not the person who knows how to solve it, but the person who knows how to solve it the way they want. What I noticed is that Nubank takes weeks or months to send feedback because they keep repeating this exact same process with countless candidates, then they rank the top 10 and hire those. "Top" in Nubank's view. Terrible process, no feedback. A bank that uses other more established and serious banks to develop products. Nubank is still crawling but thinks it's top dog.