Foundations
What is Observer?
One object tells many listeners when something changes. Each listener updates on its own. Nothing polls them one by one.
Learn this term every day on iPhone.
One hand-written term. A real workplace example. Thirty seconds before your day gets loud.
In real work
Observer: when the user toggles dark mode, every screen listens through an observer and colors refresh together.
How is this different from Googling it?
Google gives a definition. Prompthaus pairs each term with how it shows up in standups, PRs, prompts, and design reviews—then quizzes you until the word sticks. One term a day on iPhone.