Saurabh Kumar
Principal Engineer, Fueled

I build AI systems, study how agents do real work, and figure out what's worth building.

I’ve been writing code since school. In college I built conference websites and designed and built my university’s website on Joomla. I joined Fueled in 2012 as a web developer, and moved from PHP to Python and Django.

For the past fourteen years I’ve built backends: patient portals, a learning platform for Apple’s retail staff, grant platforms for nonprofits, and subscription and media apps. At Fueled I grew from developer to backend lead, then led the web engineering practice as a director, where the team grew from 8 to 16 across infrastructure, DevOps, platform, front end and back end.

In March 2026 I moved from managing people to managing technology, as Principal Engineer. I lead engineering on Rosey, Fueled’s AI-native delivery platform, in a small team of senior engineers, and help Fueled’s teams and clients put AI agents to work. I also support technical sales, and work on engineering foundations, such as RFCs for technical decisions.

More of my time now goes to research and product questions: how agents remember, retrieve, and get checked; how to build evals that catch real failures; and, as code gets cheaper to write, how to decide what’s worth building and how to tell it worked. Some of it turns into tools, like Pi Pocket Blackhole for long agent sessions. Projects has the full list, and my TIL notes catch what I learn along the way.

I’ve written open source since 2013. I started python-dotenv in 2014 after a credential leak at work, and helped maintain cookiecutter-django. I revived the PyDelhi meetup and ran it from 2014 to 2018, and co-founded Essentia SoftServ, a small software firm, where I was a part-time partner until 2022.

Off the clock, I’m on the outskirts of Delhi with my wife, my son Amay, and our dog Hachi, who all do a fine job of keeping me away from the keyboard.

open source
582M downloads a month

python-dotenv

Loads environment variables from .env files. I started it in 2014 and still maintain it. 8.9k stars on GitHub.

worked with
Apple The Motley Fool Victoria's Secret Tony Robbins Christianity Today NationsBenefits RevZilla Goosehead Insurance South Pole Open Technology Fund IIT Bombay 2NDFLOOR EverFi