Free courses
Languages, coding, data engineering, aptitude and English — every course free, with quizzes, puzzles and spaced recall that make it stay.
Languages
🇫🇷 French for beginners (A1)
Hold a simple conversation in French: greet, introduce yourself, ask questions, order food, and read everyday French.
8 free lessons🇩🇪 German for beginners (A1)
Hold a simple conversation in German: greet, introduce yourself, ask questions, shop, and understand everyday German.
8 free lessons🇯🇵 Japanese for beginners (N5)
Read hiragana and katakana, introduce yourself, and build simple Japanese sentences with the core particles and verbs.
8 free lessons🟡 Kannada for beginners
Read the Kannada script, greet and introduce yourself, and get by in everyday Kannada in Bengaluru and across Karnataka.
8 free lessonsEverything else
🧱 Foundations
Know how data moves through a company, and why the pieces are separate.
8 free lessons🐍 Python for Data Engineers
Write Python that survives 50 million rows, a flaky API and a code review.
14 free lessons🧩 Data Structures & Algorithms
See every core data structure and algorithm move, then solve the interview problems built on them.
16 free lessons🔧 C Programming
Learn C from zero the way a systems engineer knows it: what every line does to memory, why it crashes, and how to build real data structures in C.
3 free lessons🗄 SQL & Databases
Answer any SQL round out loud, and know why the query is slow.
11 free lessons🔀 Pipelines & Orchestration
Build a pipeline that reruns cleanly at 3 AM without you.
8 free lessons⚡ Streaming & Kafka
Reason about events, ordering and lag the way a platform team does.
5 free lessons❄️ Warehouse & Modeling
Model data so the business asks its question once and gets one answer.
9 free lessons🔥 Spark & Databricks
Make a slow job fast, and explain exactly why it was slow.
9 free lessons🛡 Quality, Testing & Ops
Be the person whose numbers people trust.
8 free lessons🏗 Scale & System Design
Answer 'what happens at 100x?' without flinching.
3 free lessons⚙️ Productivity & Craft
Run yourself like a system: what you do daily, how you keep code, how you use tools and AI.
3 free lessons🧮 Aptitude & Reasoning
Do the arithmetic in your head, fast, while someone is watching.
10 free lessons✍️ English & Grammar
Write and speak so the content is what gets judged, not the sentences.
9 free lessons🎯 Interview & Career
Perform under pressure — the skill nobody practises.
8 free lessons🎨 Frontend & the Browser
Understand the browser well enough to build a fast, accessible app with no framework — then know what a framework would buy you.
3 free lessons🐍 Backend with Python
Write Python services that hold up: typed, tested, async where it helps, and boring where it matters.
14 free lessons🚀 Deployment & Ops
Ship it, keep it up, and know within a minute when it breaks.
3 free lessons☁️ AWS for Data
Know which AWS service to reach for, and be able to defend it with a number.
1 free lessons