Harsh Vardhan Sharma
I build things, break things, and write about what happens in between.
I occasionally write about interesting things I find and debug during work - bugs that took too long, tools that clicked, ideas worth thinking through.
Recent writing
All posts → Why I built cogent42 - a single-file Claude Code bot for Telegram Apr 8, 2026
OpenClaw broke overnight due to an Anthropic policy change. Instead of fixing it, I replaced it with one file and three dependencies.
Someone tried to social engineer me via LinkedIn. My AI agent caught it. Mar 6, 2026
A recruiter DM, a GitHub repo, and a backdoor hiding in 300 lines of fake test comments.
How we dropped WhatsApp messaging costs by 85% with a product trick Oct 10, 2025
From INR 4.44 to INR 0.65 per message across 500k monthly messages - no infrastructure changes, just smarter session management.
How we cut CDN costs from $5,000/month to $200 at Katha Ads May 15, 2024
40-50TB of media per month, 125k DAU, and a two-part trick that dropped our CDN bill by 95%.