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101OneNoughtOne

Practice

Build, debug and explain your way to stronger skills.
All practice problemsCoding, design and hands-on challenges.Repository CodingHands-onFix bugs and build in a real codebase.Code ReviewHands-onFind risks and explain your verdict.Data structures & algorithmsCore patterns to advanced algorithms.Machine learningImplement ML and numerical methods.SQL & databasesQueries, data and analytical problems.HLD system designScalable architecture and tradeoffs.LLD system designObjects, interfaces and behavior.Aptitude & previous-year papersAptitude topics and exam practice.AI interview prepRehearse interviews with an AI tutor.Online compilerWrite and run code in your browser.

Learn

Follow a path, explore a concept or study at your own pace.
Learning pathsConnect lessons, visualizers and practical challenges.Algorithm visualizersStep through algorithms and see how they work.Books & readingBring your PDFs, take notes and study with AI.Daily current affairsUnderstand the news, save notes and revise the brief.Data structures & algorithmsLearn the foundations of efficient problem solving.Machine learningBuild mathematical intuition and explore ML concepts.SQL & databasesUnderstand data models, queries and transactions.System designStudy architecture, distributed systems and object design.
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101OneNoughtOne

Built one step
at a time.

Learn a concept. Solve a problem. Build something real. Your next chapter starts here.

Find your next challenge Explore the curriculum

Learn

  • DSA
  • HLD System Design
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  • Machine Learning
  • SQL & Databases
  • Practice Problems
  • Full Curriculum
  • Aptitude and PYQs

Resources

  • Algorithm Visualizers
  • Computer Networks
  • Operating Systems
  • Interview Prep
  • Learning Roadmap
  • Database Management
  • Repository Coding
  • Code Review

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From first principles to first offer.
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PERSONALIZED LEARNING

Your learning,
your schedule.

Create personalized study roadmaps with daily schedules, progress tracking, and adaptive pacing. Set your target date, and we'll map out your journey to mastery.

Create Your RoadmapLearn More
Flexible
Study schedule
Connected
Lessons and practice
Visible
Learning progress
Example study schedule
DSA Mastery
12 days remaining
On Track
Progress68%
Today's Schedule
Binary Search Trees
Lesson
Validate BST
Problem
Inorder Traversal
Problem
M
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W
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F
S
S
8
9
10
11
12
13
14
7-Day Streak
Keep it up!
HOW IT WORKS

Your personalized path to mastery

We break down complex learning paths into manageable daily tasks, so you can focus on what matters most—learning.

01

Set Your Target

Choose your deadline and we'll create a personalized study schedule that fits your pace.

02

Day-by-Day Schedule

Get a clear roadmap with daily tasks, estimated completion times, and flexible scheduling.

03

Track Progress

Monitor your advancement with visual progress indicators and completion analytics.

04

Adaptive Pacing

Pause, resume, or adjust your schedule anytime. Life happens, we adapt.

GET STARTED

Choose your learning path

Select a path below to create your personalized roadmap with custom scheduling.

Beginner

Data Structures & Algorithms

Build strong algorithmic foundations, trace algorithms visually, solve progressive DSA problems, and apply invariants in real repository and code-review exercises.

231.7h
361 activities
Create Roadmap
Intermediate

High-Level System Design

Move from architecture fundamentals to concrete system-design cases, then test consistency, failure recovery and authorization decisions through repository coding and review.

268h
319 activities
Create Roadmap
Intermediate

Low-Level System Design

Learn object-oriented design and design patterns, solve low-level design cases, and practise state transitions, persistence and error handling in real repositories and code reviews.

209.9h
290 activities
Create Roadmap
Intermediate

Database Management Systems

Study relational design, SQL, transactions and storage, reinforce query concepts with SQL problems, and apply consistency and analytical exports in repository coding and review.

221.4h
278 activities
Create Roadmap
Intermediate

Computer Networks

Master Computer Networks from fundamentals to advanced protocols. This comprehensive path covers the OSI model, TCP/IP, routing, switching, network security, and modern networking with 46 chapters and 1200+ pages.

200h
240 activities
Create Roadmap
Intermediate

Operating Systems

Master Operating Systems from fundamentals to advanced concepts. This comprehensive path covers processes, threads, memory management, file systems, I/O, virtualization, and distributed systems with 47 chapters and 1201+ pages.

196.8h
236 activities
Create Roadmap
Advanced

Machine Learning

Learn the mathematical and engineering foundations of machine learning, explore executable visualizers, implement algorithms, and validate dataset releases in repository exercises.

252.3h
328 activities
Create Roadmap
Intermediate

Data Structures & Algorithms Patterns

Master Data Structures and Algorithms through 15 chapters of coding patterns. From Two Pointers to Dynamic Programming, this path covers 320 carefully curated problems organized by technique for optimal learning progression.

174.3h
364 activities
Create Roadmap
Advanced

Machine Learning Patterns

Master Machine Learning from fundamentals to advanced techniques through 19 comprehensive chapters. This path covers 318 carefully curated problems spanning linear algebra, probability, classical ML, deep learning, reinforcement learning, and more.

155.6h
347 activities
Create Roadmap
Beginner

SQL Practice: Queries to Analytics

Progress from filtering and joins to analytical windows, time-series queries and recursive SQL, with focused database lessons and a data-export repository capstone.

149.2h
308 activities
Create Roadmap
Intermediate

Algorithms in Real Systems

Connect arrays, strings, graphs and scheduling to repository bugs and code-review decisions. Trace a small problem first, then apply the same invariant to a working service.

13.7h
25 activities
Create Roadmap
Intermediate

Backend Engineering Foundations

Learn the networking, data and object-design ideas behind a service, then implement and review authorization, state transitions and recovery in real repositories.

15.3h
28 activities
Create Roadmap
Advanced

Reliable Services & Transactional Workflows

Practise retries, atomic writes, stale updates and scheduled actions through system-design cases and repository coding paired with review.

15.2h
25 activities
Create Roadmap
Intermediate

Data Quality & Analytics Engineering

Combine SQL reporting, data preparation and dataset-release controls. Work through correctness at boundaries, time-window exports and quality gates.

16.6h
34 activities
Create Roadmap
Intermediate

Repository Debugging & Code Review

Start with a small boundary bug, then progress through validation, authorization, ordering, transactional recovery and publication. Each implementation is paired with a focused code-review challenge.

18.1h
24 activities
Create Roadmap
Intermediate

Computer Science Interview Foundations

Review the essential algorithms, operating systems, networks, databases and design concepts, with representative implementation and design practice.

16.5h
38 activities
Create Roadmap

Ready to start your journey?

Create your first personalized roadmap today and take control of your learning with structured, achievable goals.

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