Data Modeling

The Schema Is the Architecture#

Most candidates treat data modeling like a formality, something you sketch quickly so you can get back to the "real" design work. That instinct is exactly backwards. Your entity choices and access patterns determine whether you can shard your database, how fast your feed query runs, and whether your caching strategy even makes sense. Every box you draw in the architecture diagram is downstream of the data model. Get the model wrong and the rest of the design is built on sand.