Zero helps you build your skills, not replace them.
In a world where people are scared AI is coming for their job, INDEX 0 uses AI to make you the one who can't be replaced. It's a full learning platform for engineers, running entirely on your own machine: DSA, ML/AI, electronics, system design, mock interviews, and a few games for when you need a break. No cloud, no subscription, no shortcuts. At the end of the day, it comes down to what you can actually do when there's no tool, no LLM, nothing but you and the problem.
Free forever · 400+ problems · runs 100% offline · Mac, Windows & Linux
Gradient descent, the slow way first.
Every step gets smaller as the loss gets closer to its minimum. It's the same idea Zero uses on you: correct the error, take a smaller step next time, and actually understand why the error shrank. This is the same 3D view you get inside the app.
Why that resistor's value matters.
Zero won't just tell you to add a 220 ohm resistor. It asks what happens to the LED if you don't, until Ohm's law stops being a formula you memorized and becomes something you can reason from.
Where does this break first?
Zero doesn't start with the diagram. It starts by asking what happens when Server A goes down, or when ten thousand people hit this at once, until the diagram is something you could defend, not just draw.
Load Balancing
A load balancer sits between clients and your servers, spreading incoming requests so no single machine gets overwhelmed. The two common strategies are round robin, which cycles evenly through servers, and least connections, which sends new requests to whichever server is handling the fewest right now.
Round robin is simple and predictable. Least connections adapts better when requests vary a lot in cost, one user exporting a huge report shouldn't leave four other servers idle while one drowns.
Pattern Map, live demo
ROUND 0Watch the pattern, then it plays itself back.
This is one of the actual break-time games in the app: same recall and pattern-spotting muscle you use mid-problem, not just idle scrolling.
Where INDEX 0 has spread.
INDEX 0 started three years ago as an idea from one girl who loved to learn and believed knowledge should be free. Today it's been downloaded thousands of times across the world, and it's still growing. Take that as proof: anything is possible with enough persistence.
What people are saying
All reviews
INDEX 0 License
Copyright (c) 2026 Madhumitha Kolkar. All rights reserved.
This is not an open-source license. INDEX 0 is free to use, but the source code and content remain fully owned by the author.
What you CAN do
- Download and run INDEX 0, for free, for personal or educational use.
- Use everything the app teaches - the DSA practice, the coaching, the roadmap, the interviews - for your own learning, with no restriction.
- Share links to the official download page or repository with others.
What you CANNOT do, without written permission from the author
- Redistribute INDEX 0's installer, application, or source code through any channel other than the official one (index-0.in and its linked GitHub releases).
- Modify, repackage, or rebrand INDEX 0 - in whole or in part - and distribute it under a different name, as your own product, or as part of another product.
- Sell, sublicense, or charge money for INDEX 0 or any derivative of it, or use it as part of a paid product or service.
- Decompile, reverse-engineer, or extract INDEX 0's source code, content, prompts, or underlying methodology for the purpose of building a competing product.
- Use the name "INDEX 0", its logo, or any confusingly similar branding for another product or service.
Ownership
All source code, written content, curriculum design, coaching prompts, and branding in INDEX 0 are the original work of the author and remain the author's property. Running the app or using it for free does not transfer any ownership or license to the underlying code or content beyond what is explicitly granted above.
No warranty
INDEX 0 is provided "as is," with no warranty of any kind, express or implied. The author is not liable for any damages arising from its use.
Contact
For permission requests, licensing questions, or anything not covered here, reach out through the contact options on this page.
One app, four ways to actually get better.
The internet already has more tutorials, threads, and playlists than anyone could get through, scattered across a hundred tabs with no one telling you which ones actually matter. INDEX 0 puts DSA, ML/AI, electronics, and system design in one place instead, all coached by the same Zero, so you're building one way of thinking instead of stitching together four different ones.
DSA Coach
The six-stage Socratic loop: understand, intuition, brute force, tradeoffs, optimize, final. Zero won't let you skip a step.
Roadmaps
Structured tracks for ML/AI, Electronics, and System Design: real lessons and case studies, not a YouTube playlist.
Interviews
A guided mock interview with Zero. Pick your specialization and level, get graded, get a report on exactly what to fix.
Fully local
Zero runs on Ollama and a Gemma model, entirely on your machine. Nothing you write is ever sent anywhere.
Zero won't hand you the answer. That's the point.
Most tools optimize for the moment you get unstuck. Zero optimizes for the moment six months from now when you see a similar problem and actually recognize it.
It's a strict coach: no working code before the final stage, guiding questions instead of instructions, and every judgment grounded in the problem's real constraints, not a model's fuzzy memory of "what LeetCode 42 is."
Download, pick a model, start learning.
Unsigned builds for now: the setup wizard walks you through installing anything you're missing, including a one-time OS permission prompt to get Ollama and Python set up.
- v1.0 · ~190 MB installer
- macOS 14 Sonoma or newer (required by Ollama)
- 8 GB RAM minimum, 16 GB recommended
- v0.1.0 · ~195 MB installer
- Windows 10 (64-bit) or newer
- 8 GB RAM minimum, 16 GB recommended
- v1.0 · ~190 MB AppImage
- Any modern 64-bit distro
- 8 GB RAM minimum, 16 GB recommended
Your OS WILL warn you before opening INDEX 0
INDEX 0 is built and maintained by one person, entirely for free. A code-signing certificate costs real money every year, which this project doesn't have yet - that's the only reason your OS shows a warning, not because anything is actually wrong. The app is fully safe: it runs 100% offline, and the source of what it downloads and does is exactly what you see on this page. A couple of one-time clicks and you're in.
- After opening the .dmg and dragging INDEX 0 into Applications, open Terminal (search for it with Spotlight, ⌘ Space).
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Paste this line and press Enter, then enter your Mac password when asked (it won't show anything as you type, that's normal). This also opens INDEX 0 for you right after:
xattr -cr "/Applications/INDEX 0.app" && open "/Applications/INDEX 0.app" - That's it - INDEX 0 launches normally from here on, every time.
- If Windows SmartScreen pops up ("Windows protected your PC"), click More info, then Run anyway.
- If your antivirus flags the installer, choose Allow / Install anyway - this is the expected, standard behavior for any unsigned app, not a sign of an actual threat.
- Nothing further to do after that - Windows remembers your choice for this file.
- AppImages don't run until they're marked executable. Open a terminal in your Downloads folder and paste this, then press Enter (it also launches INDEX 0 for you right after):
chmod +x INDEX0*.AppImage && ./INDEX0*.AppImage - Some file managers show a "Trust this executable?" prompt when double-clicked instead - just click through it, that's the same one-time check.
- That's it - it runs normally from here on, every time.
Getting properly signed costs about $300/year, which this free, one-person project doesn't have covered yet. If INDEX 0's helped you, an optional coffee (see the button in the corner) goes straight toward that - and toward Zero staying free for everyone else.
Install
Open the app. If Ollama or Python aren't already on your machine, the wizard offers to install them for you.
Pick a model
Small, Balanced, or Best quality, matched to your machine's RAM and shown up front before you download anything.
Start learning
Everything from here runs offline. Open a problem, pick a track, or start a mock interview with Zero.
Need an older version, or want to see what changed in each release? See every release →
Why I built INDEX 0.
I've spent a good portion of the last few years mentoring people on DSA, career advice, interviews, all of it. To this day I wake up to messages seeking guidance. And while I've tried my best to attend to as many people as I can, I realized I had to do something to help people before they even asked for help.
I started to notice a pattern. It wasn't that people weren't enthusiastic enough, or that they lacked resources, it was that there were too many resources, and that was leading people into a spiral of the ‘paradox of choice’. I'm someone who likes uncertainty and finding my own path, but I came to realize that most people like order and certainty. If I wanted to help them, I had to create something that had everything in one place, not a hundred browser tabs of scattered content. So I built INDEX 0.
I've tried to build my personal values into it:
- I don't believe in competing with others, for me it's always me against me. That's why the app stays local and doesn't set up competition among users.
- I value privacy and security. In a world where data is power, I want this app to run locally, with people owning their own data. Everything stays on your machine.
- I love ‘delayed gratification’. I love the process of putting in effort to learn something, and by the concept of ‘desirable difficulty’, that struggle is what helps it stick long-term. So while most people would reach for short-form video, I consciously chose to stick with textual lectures, so people sit and read, which is a rarity in the modern world.
- I believe in positive reinforcement. Everyone likes words of affirmation, and someone who remembers their tiny wins and celebrates them. That's what Zero does :)
And finally, I believe that knowledge should be free. So INDEX 0 is my gift to the world, it is and always will be free, so go learn, and always keep learning :)
Madhumitha KolkarFounder, INDEX 0
Want a human in the loop too?
Zero is great for daily practice. Sometimes you want someone to talk through a career decision, review your resume, or mock-interview you live. Book time directly with the person building INDEX 0.
- 45-minute 1:1 video sessions
- DSA/system-design review, resume review, or general career advice
- Async follow-up questions included
Tried INDEX 0? Tell us how it went.
Something broken, confusing, or missing? Report it here. Liked using it? Say that here too.