ORM
Object-Relational Mapping: a library that lets you interact with a database using your programming language's objects instead of raw SQL. Drizzle, Prisma, and SQLAlchemy are ORMs.
What is ORM?
Object-Relational Mapping: a library that lets you interact with a database using your programming language's objects instead of raw SQL. Drizzle, Prisma, and SQLAlchemy are ORMs.
ORM is a foundational concept that sits in the Database Fundamentals area of system design. Engineers reach for it whenever they need to reason about real-world trade-offs in that space — not just for textbook correctness, but because real production systems at companies like Netflix, Amazon, and Google make these decisions every day.
If you want to go deeper than this definition — with diagrams, code, and a quiz to lock it in — work through the "ORM" lesson linked below. It walks through the why, the mechanism, the trade-offs, and how the giants actually use it in production.
Learn ORM in depth
Full interactive lesson with diagrams, code examples, real-world references, and a quiz.
Open the ORM lessonRelated lessons
Lessons that touch on ORM as part of a larger topic.
Database Denormalization
Intentionally adding redundancy for read performance, when breaking the rules is the right call
foundation · database fundamentals
Data Transformation
Convert data from one format, structure, or representation to another, the glue between incompatible systems
intermediate · data governance compliance
Performance Testing
Measuring and optimizing response times, throughput, and resource usage to meet performance SLAs
intermediate · devops cicd
Normalizer Pattern
Convert messages from different formats into a common structure before processing
intermediate · messaging event systems
Image Formats
JPEG, PNG, WebP, AVIF, SVG: understanding when to use each format and why it matters for performance
intermediate · web content delivery
See also
Related glossary terms you might want to look up next.
SQL
Structured Query Language for managing relational databases. Tables, rows, columns, and powerful joins to query related data.
Database
An organized collection of data that can be easily accessed, managed, and updated. The backbone of almost every application.
Connection Pool
A cache of reusable database connections that avoids the overhead of opening and closing a new connection for every query. Critical for high-throughput applications.