timloehr.me
timloehr.me

Learn the data & AI stack by doing

Six hands-on courses with live, in-browser simulators you can poke, break, and rebuild. Zero signup, zero install — open a course and start learning.

6courses
90+lessons
40+live sims
$0no signup
Self-paced Runs in your browser MIT licensed
All courses
Preview of the Data Engineering Fundamentals course ⚙️ Course 01 ★ Flagship

Data Engineering Fundamentals

Build production-grade data pipelines from the ground up — ETL patterns, batch & streaming, partitioning, orchestration, and data quality.

10 chapters 15 live simulators
PythonSQLAirflowdbtSparkKafka
Start course
Preview of the Data Science Fundamentals course 📊 Course 02 Intermediate

Data Science Fundamentals

From exploratory analysis to model deployment — statistical thinking, CLT, SHAP, A/B-test power, causal DAGs, drift, and a full capstone.

13 chapters live simulators
Pythonpandasscikit-learnPyTorchMLflow
Start course
Preview of the Data Infrastructure course 🏗️ Course 03 Advanced

Data Infrastructure

The data stack at staff-engineer system-design depth — storage internals, CAP/PACELC, lakehouse, streaming & watermarks, CDC, idempotency, SLAs.

12 lessons 7 interactive widgets
SnowflakeBigQueryKafkaIcebergSpark
Start course
Preview of the Codex Course 🤖 Course 04 All levels

Codex Course

A terminal-first playbook for the OpenAI coding agent — mental model, sandboxing, AGENTS.md, task specs, and review loops to ship real engineering work.

12 lessons + capstone
CodexOpenAIAGENTS.mdSandboxingPull Requests
Start course
Preview of the Claude Course ✨ Course 05 All levels

Claude Course

Prompt like you mean it — prompt anatomy, context engineering, CLAUDE.md, agents & tool use, grounding, evals, and safety, in twelve hands-on lessons.

12 lessons live widgets
ClaudeClaude CodeMCPPromptingEvals
Start course
Preview of The AI-Native Operator course 🧭 Course 06 All levels

The AI-Native Operator

An operating model for working AI-native — the mindset, engineering practice, and org design for shipping with AI agents, across nine modules of exercises and quizzes.

9 modules 39 lessons
AgentsWorkflowsOrchestrationEvalsOrg Design
Start course