About
I've reported vulnerabilities to Meta, Microsoft, and the Mumbai Police (through CERT-In), and my backends have handled payments, ticketing, and media for events with thousands of attendees.
I'm studying IT at NMIMS Mumbai (class of 2028) and working as a security engineer intern at R.U.D.R.A Cybersecurity. I take on freelance work — security assessments, penetration testing, and backend or API builds. The fastest way to reach me is contact@jkartik.in.
Security research
On the defensive side: hardened infrastructure protecting 16,000+ users' data, and stopped a ransomware incident with a backup-and-recovery deployment under pressure.
Projects
All projects →Writing
All posts →
Building conc-qr, Social Conclave's check-in system
The system behind Social Conclave's badge scanning with role-based access, a live-editable permission matrix, and a race condition I fixed by accident while chasing latency.
The server can't read this: designing zero-knowledge sharing
How GhostShare shares notes and files in real time while making the server mathematically unable to read them — in-browser key derivation, AES-GCM, and direct-to-R2 encrypted uploads.
A B-Tree on disk: writing a storage engine from scratch
What actually happens between INSERT and the disk — building bad-db's on-disk format, a hand-rolled B-Tree index, tombstones, and compaction in plain Java.
Where LLM guardrails break: notes from running a jailbreak contest
I built a prompt-injection contest and handed a few hundred people a scoreboard and a reason to break it. Here's what actually cracks an LLM's guardrails — and what it means for defending them.
Experience
R.U.D.R.A Cybersecurity
Security engineer intern- Automated attack-surface monitoring with BBOT, cutting ~$20k/yr of manual work.
- Built a custom Semgrep module with findings visualized in Neo4j.
- Found two high-severity vulns (LFI, broken access control) in a banking client's portal via manual code review; automated detection with Nuclei.
- Purple-team exercises with Sliver C2.
ACM MPSTME
Chairperson- Chairperson of ACM MPSTME (since 2026), my college's computing society — leading its technical direction. Head of Technical Department across NMIMS's biggest student bodies in 2025–26: Taqneeq (the tech fest), MUN Society / Mumbai MUN, Social Conclave, and Sattva — where I led the platforms and apps thousands use each year.
- Shipped Delego, the Mumbai MUN delegate app, to the App Store and Play Store — and built the FastAPI backend running it for 600+ delegates.
- Built fest infrastructure at scale: a gamified loyalty/credits backend and a Discord onboarding system that registered 1,100+ hackathon participants.
Also: 1st globally at the chat.win AI Jailbreakathon (LLM attack & defense) · 1st at Taqneeq CodeForge 2026 · Rank 1 in Smart India Hackathon's internal round · open-source contributor (SWFT) · NMIMS Mumbai IT, class of 2028.
Have something to build — or break?
Open to freelance work: security assessments, penetration testing, and backend/API builds.
contact@jkartik.in