Backend Study Lab

Structured backend curriculum

Build judgment, not just a list of definitions.

Choose a path, work through connected lessons, check your understanding, and return exactly where you left off.

Your learning plan

Start with a clear learning path.

Choose a course, follow the lessons in order, and check your understanding as you go.

Start a learning path

Six learning paths · 77 lessons

Choose the system you need to understand next.

Lessons may support more than one path. Completing a shared lesson counts everywhere it appears.

01

System Design

Design reliable backend systems through data, traffic, async work, and failure trade-offs.

Data and consistency · Database performance and operations · Reliability and resilience · Async processing · Traffic and API architecture · Additional guided lessons
22 lessons →
02

Java Collections

Choose Java collections by access pattern, correctness constraints, and performance behavior.

Map fundamentals · Equality and hashing · Set choices · List choices · Queues and priority · Complexity and performance
14 lessons →
03

API Design

Build clear API contracts that remain predictable through errors, retries, and change.

API style and contracts · Responses and errors · Authentication and access · Reliability and retries · Data and integrations · Implementation and delivery
27 lessons →
04

Authentication

Understand identity, tokens, sessions, OAuth, and browser security boundaries.

Authentication architecture · Token lifecycle and claims · Browser security risks · Protected API behavior
28 lessons →
05

Backend Security

Protect APIs, credentials, sessions, integrations, and operational trust boundaries.

Identity and access control · Token and session safety · Browser and cross-origin risks · Operational security · Secure API behavior
34 lessons →
06

Algorithms

Build practical complexity judgment for search, arrays, heaps, and backend code reviews.

Complexity fundamentals · Array and subarray patterns · Search and sorted data · Heaps and top K · Java collection choices
11 lessons →