Free for every learner. No paid tier.
Master technology.
Build with confidence.
Learn data structures, algorithms and system design from explanations that draw what they describe, then practise in an editor that replays your own code. Colleges get Campus: exams, assignments and interview preparation on top.
- courses
- 3
- chapters
- 77
- problems
- 150
- patterns
- 20
def reverse(nums): left, right = 0, len(nums) - 1 while left < right: nums[left], nums[right] = nums[right], nums[left] left += 1 right -= 1 return numsnums
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Learn
Three courses, written to be understood
Each course runs in dependency order and draws what it explains. Chapters end with a quick check, and the problems you solve come back for revision.
Data Structures & Algorithms
10 sections · 29 chapters
Complexity, arrays, hashing, pointers, windows, binary search, lists, stacks and recursion, in dependency order, with every step drawn.
Start the courseSystem Design
10 sections · 27 chapters
Scale, latency, replication, partitioning and consistency — and the trade-offs between them.
Start the courseLow-Level Design
8 sections · 21 chapters
Responsibilities, relationships, SOLID and the design patterns that actually come up, with their costs stated.
Start the course
Prefer to start from a pattern? Browse the 20 algorithm patterns
Learn · Practice
Write it, run it, watch it work
The editor, the tests and the visualizer sit side by side on every problem.
Every problem draws its input
The array, list or grid from the sample is on screen before you write a line.
Your own solution, replayed
Run Python or JavaScript and the picture steps through your code with the current line marked. Tracing runs in your browser.
Real tests on an isolated service
Python, JavaScript, Java and C++ run against the problem's tests away from the web server. A failure shows the case that broke; if the service is off, the editor says so.
A tutor that asks, not tells
It reads the chapter and the code in your editor, and walks you toward the answer instead of handing it over.
Campus
Campus: the college edition
Everything in Learn, run by your college: faculty assign courses and problems, set timed exams and grade them, and students prepare for placements with mock interviews, preparation tracks and roadmaps. Personal notes and highlights stay private; the college only sees the work it assigns.
Classes and assignments
Assign chapters, courses or problems with a due date. Progress comes from the work itself.
Assessments
Multiple-choice and coding questions from reusable banks, with server-enforced time windows and autosave.
Grading and records
Grade and release results; every change to grades and membership is kept in an audit trail.
Analytics
Participation and median scores per class from real attempts. No data shows a dash, never a zero.
Mock interviews
Students talk a problem through with an AI interviewer. Its feedback quotes their answers and is a practice signal, not a hiring assessment.
Interview preparation
Preparation tracks for the shapes interview loops come in, tied back to the chapters and problems behind each topic.
Roadmaps
Ordered study plans built from the courses, so students always know what to work on next.
Practice from Learn
Faculty assign the same courses, patterns and problems individual learners use, so nothing is duplicated.
Colleges are set up by the Tech-Epitome team. Faculty and students join by invitation or by verifying a college email.
Open your college workspaceHow a chapter works
The loop every chapter runs you through
1See
A worked example, stepped one frame at a time.
2Recognise
The clues that tell you which pattern applies.
3Practise
A guided problem, then one with no scaffolding.
4Explain
Say why it works, and what it costs.
5Recall
Spaced revision, scheduled from how well you remembered.
Every course, every problem. Free.
No paid tier, no card. Create an account to save your progress, notes and revision schedule.