Avenash Kumar · New York, USA
I design and run real-time fraud and payment systems that decide in under 200 milliseconds, and I build privacy-first tools that do their work entirely in your browser. This site is where I write about the engineering, share videos, and show the products.
Five products I designed, built, and run. Two are tools that never upload your files, two more run at the edge on Cloudflare Workers, and the fifth is a small shop born in my daughter’s first year.
A complete JSON workbench: formatters, validators, converters, schema tools, code generators, a graph view, a jq playground, and JSON-LD processing. Everything runs in the browser; nothing is uploaded.
Merge, split, sign, redact, and read text off a scan, all in your browser. PDF work usually involves contracts, statements, and identity documents, so the files stay on your device.
The storefront for CubCozyCrafts, my Etsy shop selling instant-download printables for a baby's first year: nursery wall art, milestone cards, newborn care logs, and planners in a soft watercolor woodland style.
Shorten a link with a custom slug, grab its QR code, and track clicks by country and device. Free, fast at the edge, no signup needed.
Check status, headers, timing, and redirects for any URL, from the server side so CORS does not block you. Includes a temporary webhook inbox for testing webhooks without a public server.
Notes on software engineering, programming languages, fraud and payments, and applied AI.
Java 25 is the new long-term support release. Here is what it actually changes, with code you can run, explained so a junior developer or a student can follow along.
Java 21 is the long-term support release where virtual threads finally became permanent. Here is what it actually changes, with code you can run, explained so a junior developer or a student can follow along.
Java 17 is the long-term support release that most teams upgraded to from Java 8 or 11. Sealed classes, records, text blocks, and switch expressions all became permanent here. Here is what it actually changes, with code you can run, explained so a junior developer or a student can follow along.
Talks and walkthroughs from my YouTube channel, on AI applications, Kubernetes, and the Java platform.
Most of my career has been spent on systems that cannot afford to be slow or wrong. Away from the keyboard I am a new dad, which is how a fraud engineer ended up designing nursery wall art at 2 a.m.
I read every message. The fastest route is email, and the contact page has the rest of my profiles.
