High-level design.

also: HLD · high level design

The big-picture design: which components exist, how they connect, how data flows and why each technology was chosen.

the two-minute refresher

HLD answers: what are we building and how do the pieces fit together?
It covers the architecture diagram, the components and their jobs, the data flow, technology choices and the scaling strategy.
Boxes and arrows, not code: the audience is architects, stakeholders and the interviewer.
In an interview it takes most of the time; start here, then deep-dive (LLD) where the interviewer points.

also: HLD · high level design

The big-picture design: which components exist, how they connect, how data flows and why each technology was chosen.

HLD answers: what are we building and how do the pieces fit together?
It covers the architecture diagram, the components and their jobs, the data flow, technology choices and the scaling strategy.
Boxes and arrows, not code: the audience is architects, stakeholders and the interviewer.
In an interview it takes most of the time; start here, then deep-dive (LLD) where the interviewer points.