Sperm's lifespan. It takes around 10 weeks for the sperm to reach maturity. Once the sperm is inside the woman's body it can live up to 5 days or even longer under favorable conditions. However, when it is outside the body, it can only survive from few minutes to several hours.
The UX developer role is a discipline under the overall user experience umbrella. This means that to become a UX developer you need to have at least a general understanding of the core UX principles, philosophies, and methodologies.
User stories are a type of boundary object. They facilitate sensemaking and communication, that is, they help software teams organize their understanding of the system and its context. User stories are often confused with system requirements. A requirement is a formal description of need; a user story is an informal description of a feature.