TLS stands for Transport Layer Security, essentially it ensures that communications between source and destination are secure (source being a computer, and destination being the website you are talking to, as an example).
Engineers need room to breathe and think. Very few engineers are able to solve a problem competently under pressure of multiple people watching them and within a tight time frame. It is however prudent to give newer engineers bigger and bigger problems to solve to help build their knowledge, confidence and understanding of the system and problem space.