Free courses
Every lesson is free to read and needs no account, no email and no trial. Two of these are full language courses; two are short and specific. All of them name the trap before an interviewer does.
4 courses · 33 lessons · about 5 hours of reading
Short course · Beginner to intermediate
Embeddings, RAG and LLM internals — explained at the depth an interview panel expects, not at the depth a research paper expects.
Language · Beginner to intermediate
Twelve lessons that take you from how the interpreter works to the six patterns behind most coding-round questions. Written to be read once and remembered.
Short course · Beginner to intermediate
Three lessons on what a reviewer actually opens, what they check in ninety seconds, and the JavaScript questions that follow.
Language · Beginner to intermediate
Twelve lessons from the JVM to the Collections framework, written around the questions service companies actually ask in the technical round.
About practice
That is not a paywall trick — it is a difference in what the practice needs. A multiple-choice set can be marked in a browser with no account, so those are free here. Running your Python against hidden test cases needs a real sandbox, a queue and somebody paying for the compute, so that lives inside the platform.
The Python and Java courses are complete on their own — you can read every lesson and never sign in. The practice track is what turns reading into a score.
Being written next
These are the tracks with the most placement weight, and they take the longest to write to the standard of the two language courses. If you want to know when one lands, leave your email — that is the only thing it will ever be used for.
One email per course. No newsletter, no digest, nothing else.
Free to learn · paid to be measured
Every lesson on this site is free and needs no account. What a subscription buys is the graded practice, the full-length mocks, the spoken AI interviews and a readiness score you can act on.