Placement prep, mapped.
CS theory, DSA, NeetCode 150, SQL, aptitude, system design and ML — sequenced like a course, with in-browser coding in C, C++, Java and Python.
349 topics & problems · 184 coding problems · 8 modules
Eight modules, one path
CS Theory
Operating systems, DBMS, computer networks and OOP — the four subjects every placement interview checks.
DSA Basics
Ninety problems that build loop, array and string fluency — from warm-ups to exam-level questions.
Story Problems
Ninety-four long-form problems written like real online-assessment questions, grouped by the pattern they hide.
SQL
Seventy questions on one realistic database, run on a real PostgreSQL engine inside your browser.
Aptitude
Quantitative, logical and verbal aptitude by topic, with formula sheets, worked solutions and timed mocks.
System Design
The building blocks of large systems and the classic interview case studies, drawn out step by step.
Built for the way placements actually work
Run code in your browser
C, C++, Java and Python compile and run right on the page. No installs, no waiting for a server, verdicts in a second.
A video on every big topic
Each topic pairs written notes with a hand-picked YouTube explanation, so you can read or watch.
Diagrams that explain
System design and theory topics come with architecture and flow diagrams you can zoom on your phone.
Real SQL practice
A full Postgres engine runs in your browser. Write queries against a real schema and get checked instantly.
Timed aptitude mocks
Topic-wise practice sets with worked solutions, then full mock tests under exam timing.
Progress that remembers
Pick up where you left off on any device. Your dashboard shows exactly what is left in every module.
One payment. Every module. For good.
Lifetime access to everything on solulu, including all future lessons and problems. Or try two months first.
Questions
Is any of it free?
Yes. CS Theory (OS, DBMS, Networks, OOP) is almost entirely free, and every other module has free lessons and problems at the start so you can see the quality before paying.
Which languages can I code in?
C, C++, Java and Python. Everything compiles and runs inside your browser on a laptop or desktop. On phones you can read every problem, explanation and solution.
How is this different from free YouTube playlists?
Everything is sequenced, written up properly, tested and connected: notes, diagrams, a curated video, practice problems with hidden tests, quizzes and progress tracking in one place.
Can I get a refund?
No. All sales are final, which is why so much of the site is free to try first. Please read the free lessons before you buy.