Notes from the workbench
Writing about design, development and the space in between: things I learn while building and running my own products. Subscribe by RSS.
2026
How to Validate a Signature in a PDF (Free, on Phone or Laptop)
How to validate the digital signature on a PDF for free, on a phone or a laptop: what the check proves, the five steps, and what each result means.
Question Mark in a Digital Signature: How to Remove It
The yellow question mark on e-Aadhaar, birth certificates and e-PAN is a picture stored in the PDF. Why it appears, and how to get a copy with the green tick.
What to Look For in an Open Interest Analysis Tool
What to look for in an open interest analysis tool for NIFTY and SENSEX, from the person who built OIData: change in OI, build-ups, history, alerts and price.
OI Data Explained: How to Read Open Interest for NIFTY and SENSEX
OI data explained: what open interest is, where the numbers come from, and five ways to read it for NIFTY and SENSEX, from change in OI to PCR and futures.
Interactive Product Demo Examples I Built for My Own Apps
Interactive product demo examples I made for my own apps, OIData and ShotDemo: how each was built, what every step says, and what to copy for your own demo.
Why I Built a Supademo Alternative You Pay for Once
Why ShotDemo is a Supademo alternative you pay for once: $12 per demo instead of per creator each month, what it does, and when Supademo fits better.
Beware: How BetterCV Uses Dark Patterns & Shady Billing to Charge You for "PDFAID"
Seeing an unexpected charge from pdfaid.com on your credit card statement? You aren't alone. Here is exactly how BetterCV uses fraudulent cancellation mazes and sister-company billing names to take your money without your clear consent.
Open Interest Data Analysis App - Launching my 2nd SaaS
After transitioning away from trade execution tools, I realized the real edge in options scalping isn't just about how fast you can click "buy," but how clearly you can read the market's hidden forces. Today, I'm thrilled to announce the beta launch of my second SaaS: OIData.
AmpTrade (formerly steadfastapp) Is Now Free & Open Source
SteadfastApp stopped making money, it required continuous efforts to keep things working, so I have stopped working on the app and open sourced it under a new name called AmpTrade.
2025
2021
2018