PrepAce
Live cohorts · DSA · LLD · HLD

Prepare for tech interviews with engineers who run them

Live 8-week cohorts in DSA and System Design, taught by engineers who run interviews. Weekend classes, graded 1:1 mock interviews and a resume review.

  • Small live batches
  • 8 weeks
  • 52 live hours
DSA · from 28 Nov System Design · from 5 Dec
Job referral support for every student who completes the cohort. How it works →
Early-bird on DSA ends inEarly-bird on DSA ends Sat 14 Nov, 12:00 am IST
DSAPatterns · graphs · DPA binary search tree visited level by level: 8, 3, 10, 1, 6, 9, 14831016914bfs: 8 → 3 → 10 → 1 → 6 → 9 → 14LLDClassesLLD class diagram: ParkingLot has Levels; Levels pick spots through a SpotStrategy interfaceParkingLot- levels: List+ park(v): TicketLevel- spots: List+ findSpot(v)«interface»SpotStrategy+ pick(spots)composition ◆ · strategy patternHLDSystemsHLD request path: client to load balancer to two API servers, backed by a cache and a databaseclientlbapiapicachedbclient → lb → api → cache / db

Included in every cohort

16live classesSaturday and Sunday classes
8doubt sessionsone a week, on a weekday
52live hoursof teaching in total
2graded 1:1 mockswith written feedback
1resume reviewper student
  • Recordings of every class
  • A WhatsApp community for your batch
Cohort 01 · Sat 28 Nov – Sun 17 Jan

DSA Interview Cohort

8 weeks of live classes taking you from arrays and hashing to graphs and dynamic programming: the patterns product-company coding interviews test.

Weeks 1–8 · foundations to interview strategyA binary search tree visited level by level: 8, 3, 10, 1, 6, 9, 14831016914bfs: 8 → 3 → 10 → 1 → 6 → 9 → 14

Who it's for

Final-year students and engineers with 0–3 years' experience who know one language and basic arrays and strings. Not for absolute beginners.

By week 8

Solve most medium problems across the core patterns in about 30–40 minutes, and explain your approach out loud.

Co-led by

Rahul K.

Rahul K.Teaches 14 of the 16 live classes, from arrays and hashing to graphs and DP, and runs every weekly doubt session.

Shubham Khanna

Shubham KhannaTeaches the week-8 interview classes: thinking aloud, edge cases and getting unstuck on Saturday, then a live mock demo, resume tips and how to apply and get referred on Sunday.

Early-bird pricePrice
₹9,999Regular price ₹12,999
₹12,999

Then ₹12,999. Inclusive of all charges.

Early-bird ends Sat 14 Nov, 12:00 am IST

Early-bird has ended. Inclusive of all charges.

Small live batch
Starts
Sat 28 Nov
Ends
Sun 17 Jan
Format
Sat + Sun 2.5 h · 1 weekday doubt session
Referrals
Job referrals when you complete the cohort
Enroll in DSA

UPI, cards and net banking via Razorpay

Week by week

  1. Week 1 · 28–29 Nov

    Foundations

    SaturdayRahul
    Complexity, arrays, hashing, prefix sums
    SundayRahul
    Two pointers + sliding window
    WeekdayRahul
    Doubt session, 1.5 h
  2. Week 2 · 5–6 Dec

    Search and linear structures

    SaturdayRahul
    Binary search (incl. on the answer)
    SundayRahul
    Stacks, queues, monotonic stack; linked lists
    WeekdayRahul
    Doubt session, 1.5 h
  3. Week 3 · 12–13 Dec

    Recursion and trees

    SaturdayRahul
    Recursion + backtracking
    SundayRahul
    Trees I: traversals, BST, recursion on trees
    WeekdayRahul
    Doubt session, 1.5 h
  4. Week 4 · 19–20 Dec

    Trees II, heaps, greedy

    SaturdayRahul
    Trees II: LCA, path problems; heaps / priority queues
    SundayRahul
    Greedy + intervals; how interviews are scored
    WeekdayRahul
    Doubt session, 1.5 h
    Mock 1 this week
  5. Week 5 · 26–27 Dec

    Graphs

    SaturdayRahul
    Graphs I: BFS/DFS, grids, cycle detection
    SundayRahul
    Graphs II: topological sort, union-find, Dijkstra
    WeekdayRahul
    Doubt session, 1.5 h
  6. Week 6 · 2–3 Jan

    Dynamic programming

    SaturdayRahul
    DP I: 1-D, knapsack family
    SundayRahul
    DP II: 2-D, strings, LIS, partitions
    WeekdayRahul
    Doubt session, 1.5 h
  7. Week 7 · 9–10 Jan

    Advanced DP and a timed contest

    SaturdayRahul
    DP III: trees, intervals, bitmask (overview) + tries
    SundayRahul
    Mixed timed contest + review
    WeekdayRahul
    Doubt session, 1.5 h
  8. Week 8 · 16–17 Jan

    Interview strategy

    SaturdayShubham
    Interview strategy: think-aloud, edge cases, handling being stuck
    SundayShubham
    Live mock demo + resume + applying/referrals
    WeekdayRahul
    Doubt session, 1.5 h
    Mock 2 this week
Included

Job referrals when you complete the cohort

Job referrals for every student who completes the cohort: attend at least 75% of live classes and finish both graded mock interviews.

  • 2 graded 1:1 mock interviews (weeks 4 and 8, 60 minutes each) with a written scorecard
  • Weekly problem sets, about 25 problems a week
  • A resume review · recordings of every class · a WhatsApp community for your batch
Cohort 02 · Sat 5 Dec – Sun 24 Jan

System Design Cohort (LLD + HLD)

8 weeks of live classes on low-level design (SOLID, design patterns, machine coding) and high-level design (databases, caching, queues and real case studies) for SDE-1 to SDE-2 interviews.

Weeks 1–3 · LLDLLD class diagram: ParkingLot has Levels; Levels pick spots through a SpotStrategy interfaceParkingLot- levels: List+ park(v): TicketLevel- spots: List+ findSpot(v)«interface»SpotStrategy+ pick(spots)composition ◆ · strategy pattern
Weeks 4–8 · HLDHLD request path: client to load balancer to two API servers, backed by a cache and a databaseclientlbapiapicachedbclient → lb → api → cache / db

Who it's for

Engineers with 1–6 years' experience preparing for SDE-1 and SDE-2 design rounds.

By week 8

Pass a 90-minute machine-coding / LLD round and a 60-minute HLD round with a structured approach.

  1. Requirements
  2. Estimates
  3. API
  4. Data model
  5. High-level design
  6. Deep dives
  7. Trade-offs

Led by

Shubham Khanna

Shubham KhannaTeaches all 16 live classes and runs every weekly doubt session, reviews your machine-coding code, and takes both of your graded mocks (LLD in week 3, HLD in week 8) with written feedback.

Early-bird pricePrice
₹14,999Regular price ₹19,999
₹19,999

Then ₹19,999. Inclusive of all charges.

Early-bird ends Sat 21 Nov, 12:00 am IST

Early-bird has ended. Inclusive of all charges.

Small live batch
Starts
Sat 5 Dec
Ends
Sun 24 Jan
Format
Sat + Sun 2.5 h · 1 weekday doubt session
Referrals
Job referrals when you complete the cohort
Enroll in System Design

UPI, cards and net banking via Razorpay

Week by week

  1. LLDWeek 1 · 5–6 Dec

    LLD foundations

    Saturday
    How LLD rounds are judged; OOP, SOLID, class diagrams
    Sunday
    Design patterns I: factory, builder, singleton, adapter, decorator
    Weekday
    Doubt session, 1.5 h + code review
  2. LLDWeek 2 · 12–13 Dec

    Patterns and machine coding

    Saturday
    Design patterns II: strategy, observer, state, command
    Sunday
    Machine coding live: parking lot + LRU cache, with tests
    Weekday
    Doubt session, 1.5 h + code review
  3. LLDWeek 3 · 19–20 Dec

    Machine coding and concurrency

    Saturday
    Machine coding: Splitwise / BookMyShow; concurrency basics (locks, thread-safety)
    Sunday
    LLD review: rate limiter, elevator; common mistakes
    Weekday
    Doubt session, 1.5 h + code review
    LLD mock this week
  4. HLDWeek 4 · 26–27 Dec

    HLD foundations

    Saturday
    HLD framework; estimates; DNS, load balancers, HTTP/REST/gRPC
    Sunday
    Databases: SQL vs NoSQL, indexing, replication, sharding
    Weekday
    Doubt session, 1.5 h + code review
  5. HLDWeek 5 · 2–3 Jan

    Caching, consistency, queues

    Saturday
    Caching + CDNs; consistency; CAP
    Sunday
    Queues, async and event-driven design (Kafka-style); idempotency
    Weekday
    Doubt session, 1.5 h + code review
  6. HLDWeek 6 · 9–10 Jan

    Case studies I

    Saturday
    Case: URL shortener + distributed rate limiter
    Sunday
    Case: news feed / timeline
    Weekday
    Doubt session, 1.5 h + code review
  7. HLDWeek 7 · 16–17 Jan

    Case studies II

    Saturday
    Case: chat / WhatsApp (websockets, presence, delivery)
    Sunday
    Case: ride-hailing / location (geo indexing)
    Weekday
    Doubt session, 1.5 h + code review
  8. HLDWeek 8 · 23–24 Jan

    Case studies III and a full mock

    Saturday
    Case: payments / ticket booking (transactions, exactly-once, reconciliation)
    Sunday
    Reliability + observability; full HLD mock demo
    Weekday
    Doubt session, 1.5 h + code review
    HLD mock this week
Included

Job referrals when you complete the cohort

Job referrals for every student who completes the cohort: attend at least 75% of live classes and finish both graded mock interviews.

  • 2 graded 1:1 mock interviews (one LLD in week 3, one HLD in week 8, 60–75 minutes) with written feedback
  • Machine-coding assignments, with code review in the doubt session
  • A resume review · recordings of every class · a WhatsApp community for your batch
Choose

One cohort, or the bundle

Both cohorts

DSA + System Design

₹19,999Regular price ₹32,998
₹32,998

Save ₹4,999 on the two early-bird prices

Bundle early-bird ends Sat 14 Nov, 12:00 am IST (the earlier of the two cohorts)

Early-bird has ended. One payment, a seat in each cohort.

  • One payment, a seat in each cohort
  • DSA Interview Cohort from 28 Nov
  • System Design Cohort (LLD + HLD) from 5 Dec
  • Job referrals in both tracks: complete each cohort to qualify in it
Enroll in both
Your mentors

Mentors with track records you can check

Shubham Khanna

Shubham Khanna

Senior Software Engineer

Designs backend systems and interviews engineers regularly. 7+ years experience building scalable systems at travel and fintech companies. Focuses on practical system design and interview preparation

  • Ex- Agoda (Booking Holdings), Arcesium (DE Shaw), ixigo
  • System design - LLD, HLD, Case Studies
  • Real world mock interviews
  • Resume mentoring

Teaches in: DSA Interview Cohort and System Design Cohort (LLD + HLD).

Rahul K.

Rahul K.

DSA Instructor, Competitive Programmer

Full-time DSA instructor. Helps engineers level up with curated roadmaps based on there coding journey and progress.

  • Taught 500+ students
  • LeetCode Guardian
  • Competitive Programming
  • 1,000+ problems solved on LeetCode
  • Founder, CodeGaze Community

Teaches in: DSA Interview Cohort.

Schedule

Pick your track · Live weekend classes

Saturday and Sunday classes, and one doubt session on a weekday. Class times in IST: to be confirmed

  • WeekendDSASystem Design
  • 28 NovWeek 1—
  • 5 DecWeek 2Week 1
  • 12 DecWeek 3Week 2
  • 19 DecWeek 4 · mockWeek 3 · mock
  • 26 DecWeek 5Week 4
  • 2 JanWeek 6Week 5
  • 9 JanWeek 7Week 6
  • 16 JanWeek 8 · mockWeek 7
  • 23 Jan—Week 8 · mock
Saturday2.5 h2 h teaching + 30 min live practice and Q&A
Sunday2.5 h2 h teaching + 30 min live practice and Q&A
One weekday1.5 hDoubt session. Plus 4–6 h of practice on your own
FAQ

Straight answers

Is there a job guarantee?

No. Nobody can honestly promise you a job, an interview call or a specific result, and we don't. What we do promise is the teaching: 52 live hours, 2 graded 1:1 mock interviews with written feedback, and a resume review. If you complete the cohort (at least 75% of live classes and both graded mock interviews), we also refer you at companies in our mentors' network, but a referral isn't a job guarantee: the hiring decision is the company's.

How do job referrals work?

Job referrals for every student who completes the cohort: attend at least 75% of live classes and finish both graded mock interviews. We refer you at companies in our mentors' network. A referral isn't a job guarantee — the hiring decision is the company's. The same rule applies in each cohort, and with the bundle in each of the two cohorts you complete. Attendance is counted from the live classes, and the two mocks are the graded 1:1 mock interviews in the curriculum.

Who is the DSA cohort for?

Final-year students and engineers with 0–3 years' experience who know one programming language and basic arrays and strings. It is not for absolute beginners.

Who is the System Design cohort for?

Engineers with 1–6 years' experience preparing for SDE-1 and SDE-2 design rounds: machine coding / LLD and HLD.

How much time does it take each week?

About 6.5 live hours: two 2.5-hour weekend classes and one 1.5-hour weekday doubt session. Plan another 4–6 hours for practice.

What if I miss a class?

Every class is recorded and shared in your batch's WhatsApp community.

Can I get a refund?

Full refund within 7 days of the start.

What if fewer than 6 people join?

The batch runs with at least 6 students. If it doesn't fill, you choose a full refund or a place in the next batch.

How do I pay?

Securely through Razorpay with UPI, cards or net banking. Prices are in rupees and include all charges. We never see your card, UPI or bank details.

Can I join more than one cohort?

Yes. Take the DSA + System Design bundle: one payment, a seat in each of its cohorts, ₹19,999 until Sat 14 Nov, 12:00 am IST, then ₹32,998. They run on the same weekends (DSA from Sat 28 Nov, System Design from Sat 5 Dec).

How does the early-bird price work?

Each cohort has an early-bird price until a set date, shown with a countdown on this page: ₹9,999 for DSA until Sat 14 Nov, 12:00 am IST and ₹14,999 for System Design until Sat 21 Nov, 12:00 am IST. When the countdown ends, the price becomes ₹12,999 (DSA) and ₹19,999 (System Design). Once you have paid, your price doesn't change.

Pick your track

DSA starts Sat 28 Nov. System Design starts Sat 5 Dec.

Enroll in DSA Enroll in System Design DSA + System Design bundle
DSA Interview Cohort₹9,999 early-birdEnroll