Chai Prep
System design interviews are live

Prepare for the coding interview.

Learn the subjects, practise against the clock and sit realistic interview rounds before the real one. Visual courses, notes, videos, practice sheets, aptitude mocks and AI interviews, all on one account.

Start free For colleges and companies

Your week

Placement prep, week 3

3 of 5 done

  1. MonTCP, the three-way handshakeLearn · Networking, illustrated chapter
  2. TueSliding window sheetPractise · 6 problems, C++ and Java
  3. WedAptitude mock, quantitativePractise · 30 questions, 30 minutes
  4. ThuIndexes and B+ treesLearn · Databases, with your notesToday
  5. FriSystem design roundInterview · Link shortener, 45 min

Last debrief · Code review · 4 of 5

“You caught the race in the retry loop. Next time, ask why the new query has no index before approving.”

Two pointersTCP handshakeDeadlocksB+ tree indexesDesign a rate limiterSliding windowParking lot designHow DNS resolvesTime and workPaging and the TLBNormal formsDynamic programming
Review a pull requestTransactions and ACIDGraphs and BFSTLS and HTTPSCPU schedulingLRU cacheProbabilityDesign a chat appBinary searchSubnets and CIDRThreads and locksSQL joins
184+
animated DSA problems
147+
illustrated chapters and lessons
46+
hours of video courses
221+
AI interview problems

How it fits together

Learn it, practise it, then sit the round.

Interview preparation is usually spread across a dozen tabs. Here it follows one path, and your progress, notes and streak come with you at every step.

DSA VisualFreeLLD VisualNetworkingOperating SystemsDatabasesVideo CoursesFree
two‑pointers · target 14
1
4
6
8
11
15
▲L
▲R
1 + 15 = 16 > 14, move right in

Illustrated notes

Notes that read like a good teacher drew them for you.

Networking, operating systems and databases, explained one hand-drawn page at a time. Every chapter is written with interviews in mind: what it is, why it matters, and how it comes up.

NetworkingOperating systemsDatabases

AI interviews

Sit the round before the round.

Four rounds modelled on how companies interview today. Each one ends with a written debrief that quotes your own work back to you, so you know exactly what to improve.

Explore the rounds

Round one

AI coding interview

A real codebase, an AI assistant beside you and hidden tests. You are assessed on how well you steer the assistant, not on how fast you type.

45 to 55 minutes

Round two

Code review

Review a pull request the way a senior engineer would. Find what matters, explain why, and know when approving is the right call.

20 to 30 minutes

Round three

Low-level design

Model a system class by class, then walk the interviewer through your choices and the trade-offs behind them.

45 minutes · 25 systems

Round four

System design

Design a service on a whiteboard in six clear steps, with an interviewer who answers your questions and pushes back.

45 minutes · 25 systems

Interviews from ₹99 each. System design practice mode is included in the plan.

AI roadmap

A plan that fits the time you actually have.

Tell us what you want to learn and how many days you have. You get a syllabus sized to your level, in an order that makes sense, and one clear list for each day. Miss a day and it simply moves to your backlog.

  • Any subject, from linked lists to system design
  • Algorithm tasks open straight into the visual lesson
  • One short list each morning, nothing to manage
Build your roadmap
interview prep · your plan
Mode
TimedComplete
Days
73045
Per day
124
1
2
3
4
5
6
7
8
9
10
11
12
13
14
On track0 / 60 solved · 0%

For colleges and companies

Prepare a whole batch, not one student at a time.

Placement cells use Chai Prep to get final-year students ready and run practice drives. Companies use it to onboard graduate hires and assess them before day one. You get your own portal; we handle the platform.

  • Bring everyone in at once

    Import your roster, assign seats and see who has joined and who needs a nudge.

  • Run drives on your schedule

    Aptitude, coding and code review rounds, one link for everyone, make-up windows built in.

  • Fair by design

    Papers drawn fresh for each round. Focus changes and pastes recorded, with no camera.

  • Results you can act on

    Ranked lists and score spreads, so you see who is ready and who needs more practice.

Final-year practice drive

Round 2 · Coding interview

Ended 4:30 pm

212

of 240 sat it

3.4

average of 5

28

in the make-up

  1. 121CS0414.8
  2. 221IT0174.6
  3. 321CS1024.3
  4. 421EC066Left the page 6 times4.1
  5. 521CS0883.9
  6. 621IT0453.6

Let’s set it up together.

Tell us about your batch and what you would like to achieve. We will take it from there.

  1. 1

    Tell us about your batch

    Who they are, how many, and what a good result looks like for you.

  2. 2

    See it in action

    A short walkthrough of the portal, the rounds and the reports, shaped around your plans.

  3. 3

    Go live

    We set up your portal and admins. You invite your students or new hires with one link.

Talk to us

Tell us a little about your team. We will call you, usually within two working days.

Students in the batch

Best time to call you (IST)

Questions

Good to know.

Is Chai Prep free?
You can start for free. The first DSA track, the video courses and the practice sheets are open to everyone. One plan, from ₹499 a month, unlocks every course, aptitude mock and roadmap. AI interviews are bought separately, from ₹99 each.
What happened to Chai Visual?
It grew. Chai Visual started as animated DSA lessons, and those are all still here as the visual courses. Chai Prep is the name for everything around them now: notes, videos, practice, mocks and interviews.
Who is it for?
Students preparing for placements, engineers getting ready to switch jobs, and colleges or companies preparing a whole batch together.
How are the AI interviews marked?
Every round is marked against a written rubric for that problem. Your debrief explains each score and quotes the parts of your work it is based on, so the feedback is specific and easy to act on.
Do I need to install anything?
No. Everything runs in your browser, including the codebase and editor in the coding interview.

Start where you are. Walk in ready.

Open a lesson, solve a sheet or sit a practice round today. Everything you do here builds towards the same goal: your next interview.

Start freeCreate an account