About · the whole site in one pack

A working lab, not a brochure.

The things Sarthak Gupta would rather show than describe: live quant math, an agent with a team behind it, games with a house edge, and free tools. This page is the map.

Sarthak Gupta, Data Scientist II, Finance Models at Amazon
Fig. 1 · the human, allegedly
Who runs it

Also a person.

Sarthak Gupta is a Data Scientist II, Finance Models at Amazon in Seattle, working on AI agents and quantitative models for money that matters: multi-agent systems, forecasting, risk analytics, credit decisions and model validation. Before Amazon he worked in credit risk modelling and value-at-risk research, with graduate work in financial engineering at Claremont Graduate University. He has been featured in Business Insider five times, writes for CFO.com, is quoted as an expert in CFO Drive roundups, and his comment letters have been published by the Financial Stability Board, the SEC and FINRA. He co-wrote the Quant Finance Interview Guide and runs a free mentorship hub on this site.

LinkedIn · GitHub · Email

▲Writes about agentic AI and why liability, not capability, is the bottleneck. The essays.
▲Co-wrote a quant interview guide that has been downloaded 11,000+ times, mostly at 2 a.m.
▲Built the games in the arcade. Loses to them at a statistically significant rate.
▲Three degrees, two continents, one favorite. The favorite had stochastic calculus.
The pack

Everything on the site, in one place.

Six doors. Each card says what is actually behind it, so you can pick by what you need rather than by what sounds clever.

skgpt

The resident agent

A free open-weight model with a job description, and since v3.2 a strategist that stages a whole team for the tasks that deserve one.

  • Quick mode: one plain answer in a couple of seconds, streamed from a free chain of open-weight models at the edge
  • Agentic mode: the strategist picks the format, a round table, a debate with scored rounds, a blind panel on three models, or a what-if with a thousand simulated futures, and the run ends in a memo with a verdict
  • One click opens the whole meeting, who said what and in what order; make your own agent by saying so, or speak instead of typing
  • Ten real cases with real numbers to click, and the green triangle in the logo is a shortcut here from any page
Talk to it →how it works
The Quant Lab

Live instruments

The quant math runs in your browser, every number recomputed as you move a slider. If a number looks wrong, it probably is, and you can see why.

  • Black-Scholes with the Greeks and a payoff diagram
  • A thousand-path Monte Carlo you can reseed
  • The efficient frontier, Value at Risk and a DCF valuation
  • A small neural net training live, loss curve and all
Open the lab →
The Arcade

Games with a house edge

Probability you can lose at. The coin is fair, allegedly. The market is not.

  • Fair Coin, Allegedly: a 3D flip with the law of large numbers drawn as you go
  • Random Walk: survive the market in a platformer
  • Both run in the browser, nothing to install, nothing that remembers you
Play →
Featured

In other people's words, and his

The public record, with source links on every item.

  • Comment letters published by the Financial Stability Board, the SEC and FINRA
  • Opinion bylines in CFO.com, five features in Business Insider, and quoted expert answers in CFO Drive
  • Essays on agentic AI and why liability, not capability, is the bottleneck
  • The Quant Finance Interview Guide on Zenodo, downloaded more than 11,000 times
Read →
Toolkit

The agent-skill kit

The skills he actually runs, with sources linked and authors credited, plus notsofast, the one he built himself.

  • Agents, and the evals that keep them honest
  • Finance and research tools that earn their place
  • notsofast, his first open-source skill: a guard for agentic loops
Browse →
Mentorship

Free, and meant to be used

Most people charge for this. The hub points you to the next right step and hands you the tools.

  • Job Board: recent quant, risk, data and AI roles pulled from company career pages, linking straight to the source
  • Resume Lab: a guided builder that downloads an editable, ATS-friendly .docx
  • Learning Path: a curated, opinionated route into AI and quantitative finance
  • Interview Tutor: answers from the guide, with a chapter citation
Start →the job board

Free to run, honest by construction.

The site

Static, no framework.

Plain HTML, CSS and modules, served from Cloudflare's edge. No build step, no tracking pixels, no cookie banner because there is nothing to consent to.

The models

Free and open-weight.

skgpt runs on a chain of free open-weight models at the edge, with hosted free tiers as backup. When the daily quotas are spent it says so, and the recorded cases still replay.

The rules

Audited, and not advice.

Deterministic gates check every answer for price calls, personal data and style before you see it, and the audit stamp shows what ran. Nothing here is financial advice. Views are his own.