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FreeNo card, and no paid tier later

Ninety days to
read any
system

You write Python, TypeScript and SQL. You learn why the systems built out of them break.

Start Day 1See the whole path
8
phases, in order
2–3h
a night
0
days to plan

Used by people at

MIT, Harvard, IIT Bombay, Google, Anthropic, OpenAI, UCLA, San Diego State, Northeastern, IIT Madras, Walmart, SJSU, SFSU, Infosys, TCS, UIUC, Netflix

AI can write the code. It can’t supervise it.

You can ship a working feature today without understanding a line of it. That holds right up until it breaks, or slows down, or leaks something. Then the only person who matters is the one who can read the system.

After 90 days you can

  • 01Open unfamiliar code and say what it does
  • 02Explain why it was built that way
  • 03Name what breaks first under load
  • 04Spot the security hole before it ships
  • 05Argue the tradeoff instead of guessing
  • 06Tell a good AI answer from a plausible one

Why ninety

A year of someday beats nobody.

You have already proved this works. Not by being brilliant at 2am the night before an exam, but because a fixed scope and a real date beat an open-ended year every time. Most people who plan to learn this over a year quit in month two, and nothing ever forced the next step.

The full argument, including the catch

Learning it “properly”, over a year

no end

Nothing decides what you do tonight, so most nights nothing happens.

Ninety days, starting the day you do

214 hours

Every day already chosen, in order, with an end you can see from the first one.

214
hours, all in
2-3h
a night
1
decision, ever

Eight phases. One continuous path.

No week of Python, stop, random React, stop. Functions become services, services become tools an AI can call.

Swipe for all eight

SOURCEMAP

Ninety days of this, priced elsewhere

  • A coding bootcamp$10,000+

    Twelve weeks, full time

  • A course subscription$60 to $180

    Coursera, Udemy, Pluralsight

  • Buying the courses$150 to $400

    Four or five to cover this

Total, all ninety days$0.00

No card, now or later

90 days · 8 phases · 0000 000 000

All eight phases, in order, starting tonight.

There is no paid tier here and no plan to add one. The prices on the receipt are what the same ground costs everywhere else.

Every day comes with

  1. 01One objective
  2. 02A Master Prompt
  3. 03Hand-checked sources
  4. 04Something to build
  5. 05Recall questions
  6. 06A mastery rating
Start Day 1

Everything else, all free

8 pages

Ninety days you can see at once.

Look as far ahead as you like. This is a map, not a game.

Foundations

1–12

Data & Algos

13–22

The Web

23–34

Backend

35–46

Production

47–56

Systems

57–66

AI Eng

67–76

Agents

77–90

Open the full roadmap

Taller marks are consolidation days

What mastery looks like here

Ninety marks, one per day. Each has five wedges: can you explain it, recognise it, apply it, debug it, and argue its tradeoffs. A concept is not finished because you read it. It is finished when the shape is full, and nothing here lets you skip to that.

Who made this

Every day ships only after it has survived me.

I built this because I wanted it and it did not exist: one path, in order, with the reasoning left in, instead of ninety tutorials that have never met each other.

I write a day, then run it exactly as you will, and publish what happened. Anything that does not survive that gets rewritten before you ever meet it. That is the quality control, and it is why there is no filler here.

Mihirsinh Chavda · building Sourcemap in public

Not starting today is fine. Losing the link is not.

One email when a new free tool or a write-up ships.

Ninety days from now, you’ll read code differently.

Two to three hours a day. Ninety days from the day you start, and the same curriculum other people charge a subscription for.

  • A bootcamp$10,000+
  • A subscription$60 to $180
  • Buying the courses$150 to $400
  • This$0
Start Day 1How the method works