Learning paths

Real subjects from the actual product — not a generic list.

Every path is a sequence of nodes. Each node is Learn → Simulate → Quiz. Open any track to see the same chrome students use after they log in.

Beginner · Interview core

Data Structures & Algorithms

Fixed-size, index-addressed memory — the base every other structure builds on. Then trees, graphs, DP, and the patterns companies actually ask.

ArraysHashingTreesGraphsDPTwo pointers

18 nodes · 42 hrs · +1420 XP

Beginner · Data jobs

SQL

The language every backend, data, and analytics interview still opens with. Joins, windows, and query plans — not just SELECT *.

JoinsWindow fnsIndexesCTEsQuery plans

14 nodes · 18 hrs · +880 XP

Beginner · Team ready

Git & GitHub

The difference between a student project and something a team can ship. Branching, PRs, rebase, and the incidents you'll cause if you skip this.

CommitsBranchingPRsRebaseConflicts

10 nodes · 8 hrs · +420 XP

Beginner · Foundation

Python

The language of interviews, scripting, data, and a surprising amount of backend. Idiomatic Python — not just the syntax your lab used.

IdiomsOOPStdlibTestingPackaging

16 nodes · 24 hrs · +960 XP

Intermediate · Job ready

REST API & Backend Engineering

Auth, pagination, idempotency, and the 14 ways a naive CRUD API fails in production. The track job posts actually filter on.

RESTAuthCachingQueuesObservability

16 nodes · 28 hrs · +1180 XP

Advanced · Senior signal

System Design

Capacity, trade-offs, and the diagrams that get you past the 'design Instagram' round — taught as decisions, not decorations.

LoadStorageCacheQueuesConsistency

12 nodes · 20 hrs · +1040 XP

Intermediate · Ships to prod

Cloud & DevOps

AWS, Azure, CI/CD, containers, and the ops instincts that keep a service up after you merge.

AWSAzureDockerCI/CDK8s intro

14 nodes · 22 hrs · +980 XP

Intermediate · Frontend jobs

React

Components, state, effects, and the performance instincts that keep a UI honest. The library most product teams still hire for.

ComponentsHooksStateRoutingPerf

14 nodes · 20 hrs · +920 XP

Intermediate · New stack

AI/ML Fundamentals

The math you actually need, the models companies fine-tune, and the evaluation that stops you shipping a confident wrong answer.

SupervisedNNsEvalLLMsRAG

16 nodes · 30 hrs · +1260 XP

Advanced · Ships models

MLOps & Production ML

Training is the easy part. This track is everything after: versioning, serving, drift, and the on-call for a model.

PipelinesServingDriftMonitoringLineage

12 nodes · 18 hrs · +890 XP

Landing next on PreCompilers

4 in the pipeline

In active build. XP, node counts and simulators lock in closer to release — the track names and scope are final.

Coming soon

AI Agents

Tool-calling, memory, planning loops and multi-agent orchestration — building software that takes actions, not just answers.

Tool callingMemoryPlanning
Coming soon

Gen AI

Prompting, RAG, fine-tuning and the eval discipline behind every 'we added AI to the product' feature.

PromptingRAGEmbeddings
Coming soon

QA & Testing

Test pyramids, flaky-test triage and the coverage discipline that stops 'it worked on my machine' from reaching prod.

Unit testsIntegrationE2E
Coming soon

Playwright

Browser automation that doesn't flake: selectors, network mocking, visual diffs, and CI runs across every browser engine.

LocatorsAuto-waitFixtures