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.GATE papersBranch-wise previous year papers and worked solutions.AptitudeAptitude 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.ReadingRead books, notes and research papers 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.
Find jobsFor teamsFor institutionsPricing
LoginRegister
YOUR ACCOUNT

Request account
deletion.

Ask us to delete your OneNoughtOne account and associated personal data. Use your account’s email address. We verify ownership before processing; submitting this form does not immediately delete your account.

As described in our privacy policy, deletion or anonymization is completed within 90 days after verification, except records we must retain by law. Employer copies of submitted applications are controlled by the employer. Contact support about any active subscription.

Send a deletion request

The request is recorded in our private support inbox. Keep the reference shown after submission.

Please include at least 20 characters. Keep passwords and payment details out of your message.

We use your details to respond to this request.
Read our privacy policy

OTHER WAYS TO CONNECT

Prefer email?

For support, partnerships, or a conversation about your team.

anshik@onenoughtone.com

A quick conversation

Reach out on WhatsApp for a question or a walkthrough.

+91 75031 61363

Learn with the community.

Share questions, exchange ideas, and find people building alongside you.

Join our Discord Follow on X
A LITTLE HELP BEFORE YOU WRITE

A few useful answers.

Where can I report a problem?+

Choose Report a bug in the form. Include the page URL, what you expected, and what happened. Please leave passwords and other sensitive details out of your message.

Can we see the platform as a team?+

Yes. Choose Hiring & teams for a recruiting workspace, or Schools, colleges & universities for campus access. Tell us about your team and what you want to achieve.

Where will I hear back?+

We’ll reply to the email address you include. If you already have an account, using that address helps us find the right account when you need support.

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
  • LLD System Design
  • Machine Learning
  • SQL & Databases
  • Practice Problems
  • Full Curriculum
  • Aptitude
  • GATE papers & solutions

Resources

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

Company

  • Pricing
  • Contact
  • Find Jobs
  • Job Assistant
  • For Hiring Teams
  • For Institutions

Legal

  • Terms & Conditions
  • Privacy Policy
  • Cookie Policy
  • Security
  • Accessibility

Online Compilers

  • All Compilers
  • Python Compiler
  • C++ Compiler
  • Java Compiler
  • JavaScript Compiler
  • Go Compiler
  • Rust Compiler

From first principles to first offer.
© 2026 OneNoughtOne. All rights reserved.

OneNoughtOne