Data Modeling

0 lessons

1 system design

3 community items

data-modeling

System Design

1 article

SQL vs NoSQL - Choosing the Right Database

SQL vs NoSQL is the most common storage decision in system design interviews. SQL databases give you ACID guarantees, joins, and a fixed relational schema; NoSQL databases give you flexible schemas, horizontal scaling, and specialized data models. This lesson teaches you the four NoSQL families, the real engineering trade-offs, and a clear decision framework so you can defend your database choice in any interview.

525

Community

3 items

Article

SQL vs NoSQL: Stop Asking the Wrong Question

The choice that matters is not the data model. It is which guarantees you need on read and write. A decision table and the JSONB middle ground that retired half my Mongo use cases.

967

4.3 (14)

Apr 20, 2026

by @tylerperry

Article

Database Migrations: A Zero-Downtime Playbook

Adding a column, renaming a column, dropping a column, splitting a table. The expand-contract pattern, the four-step rename, and the migration phases that have kept me from taking the site down.

659

Mar 22, 2026

by @hannahchakraborty

Article

MongoDB Aggregation Pipelines, by Example

Match, group, lookup, project, the four stages I use 90% of the time. Real pipelines for funnel analysis, leaderboard, and a one-stage join, with the gotchas that surprise SQL refugees.

582

4.5 (11)

Feb 1, 2026

by @fatimapark