GUREHMAT CHAHAL

CS Co-op · McMaster University

Seeking: Summer 2027 co-op · SWE / Backend / AI · Toronto, Hamilton, or Remote

I build backend and AI systems that ship to real users.

CS co-op student at McMaster. I've shipped production work at 4 companies, from fixing a critical security hole at Prepr to building permission-safe AI search at Aeternum.

Fixed a critical production security vulnerability exposing user data at Prepr Foundation
Built AI search over private records that only shows users what they're allowed to see (Aeternum)
Built Stripe booking and payment flows designed to prevent double charges (WareShare)
Led a 3-person team to ship an AI coaching chatbot for a live client in 4 weeks (Workplace Edge)

[ RESUME ] [ WORK ] [ EMAIL ME ]

// TECH_STACK

[ PYTHON ] [ TYPESCRIPT ] [ FASTAPI ] [ NODE / EXPRESS ] [ LARAVEL ] [ POSTGRESQL + PGVECTOR ] [ REACT ] [ STRIPE ] [ CLOUDFLARE WORKERS ] [ DOCKER ]

// WORK

Selected projects · click any card for details

wareshare@projects:~$

[ 2026 ] [ CLIENT PROJECT ]

WareShare

[ SHIPPED ]

A warehouse-sharing marketplace, basically Airbnb for warehouse space. Connects renters who need storage with hosts who have spare capacity. I led the workflow and integration side of the build.

[ NEXT.JS ] [ HONO ] [ CLOUDFLARE WORKERS ] [ STRIPE CONNECT ] [ CLERK ]

aeternum@projects:~$

[ 2026 ] [ CLIENT PROJECT ]

Aeternum

[ NDA ]

A privacy-focused AI feature for a digital-legacy platform. It lets someone semantically search their own private records while strictly enforcing per-record access control, so results never surface anything they aren't allowed to see.

[ FASTAPI ] [ POSTGRESQL ] [ PGVECTOR ] [ GEMINI ]

ai-coach@projects:~$

[ 2026 ] [ CLIENT PROJECT ]

AI Lesson Coach

[ SHIPPED ]

Workplace Edge client project. Enterprise AI coaching chatbot grounded only in the client's own lesson content (no vector DB, no RAG). Intent routing, a safety layer, and SCORM embedding. I led a 3-person team.

[ REACT 18 ] [ TYPESCRIPT ] [ GEMINI 2.5 ] [ EXPRESS ] [ PRISMA ]

meridian@projects:~$

[ 2026 ] [ PERSONAL PROJECT ]

Meridian

[ FEATURED ]

Personal knowledge graph that maps your thinking and finds where your ideas contradict each other.

[ REACT 18 ] [ TYPESCRIPT ] [ FASTAPI ] [ GEMINI 2.5 FLASH ] [ VECTOR SEARCH ]

pantrycheff@projects:~$

[ 2026 ] [ PERSONAL PROJECT ]

PantryCheff

[ SHIPPED ]

AI-powered pantry + recipe engine that reduces food waste. 154 automated tests, O(P+R) matching algorithm, 99.8% bundle optimization.

[ REACT 19 ] [ TYPESCRIPT ] [ SUPABASE ] [ GEMINI API ] [ VITEST ]

the-record@projects:~$

[ 2026 ] [ HACKATHON ]

The Record

[ WINNER · BEST ELEVENLABS ]

Live AI-powered debate referee built solo at ConHacks 2026 (36-hour hackathon). An AI judge analyzes fallacies and false claims in real time, then delivers a final credibility verdict via text-to-speech.

[ REACT 18 ] [ TYPESCRIPT ] [ GEMINI 2.5 FLASH ] [ ELEVENLABS TTS ] [ ZUSTAND ]

seed@projects:~$

[ 2025 ] [ HACKATHON ]

SEED

[ HACKATHON · BEST UI ]

MillHacks 2025 · BEST UI. Climate-tech storytelling site for coastal plastic cleanup concept. Mobile-first, responsive, judge-facing.

[ HTML5 ] [ SCSS ] [ VANILLA JS ] [ GITHUB PAGES ]

captcha@projects:~$

[ 2026 ] [ HACKATHON ]

C.A.P.T.C.H.A.

[ HACKATHON ]

Chrome Extension built solo at the Toronto Stupid Ideas Hackathon. Manifest V3, vanilla JavaScript.

[ CHROME EXT ] [ MANIFEST V3 ] [ JAVASCRIPT ]

// RESUME

Experience, education, achievements, skills

Experience

AI Programmer

Prepr Foundation · Toronto, ON (Remote) · Jun 2026 – Sep 2026

Fixed a critical production security vulnerability that exposed users' personal data to logged-out requests, adding authentication checks across 11 Laravel API resources.
Gave the team one source of truth for validation across a 1,200+ file PHP/Laravel codebase by consolidating duplicated name, email, and record checks into reusable validation rules.
Unblocked local development for a 4-person team by fixing recurring Docker crashes caused by database seeding, and flagged OAuth redirect and XSS vulnerabilities during a security audit.

AI / Backend Developer

Aeternum · Remote · May 2026 – Jul 2026

Prevented users from seeing records they weren't allowed to access in an AI search pipeline (RAG) over private data by enforcing per-record permission checks before search runs.
Improved search relevance by cutting weak, near-miss matches from results, tuning a similarity threshold on vector embeddings in PostgreSQL (pgvector).
Shipped the platform's FastAPI search and AI-answer endpoints as sole backend developer, owning 14 tickets end to end from design through code review.

Workflow & Integration Lead

WareShare · Remote · Apr 2026 – Jun 2026

Prevented duplicate charges and duplicate customer emails in production by designing a booking-to-payment workflow with Stripe that safely handles repeated payment events, built on Cloudflare Workers.
Expanded automated email coverage from 7 to all 16 required flows across signup, booking, and invoicing by building a notification system with Resend, rolled out safely behind feature flags.
Kept warehouse availability accurate across overlapping bookings by building a real-time reservation engine that tracks space across 3 booking statuses and powers the booking calendar.

AI Developer (Team Lead)

Workplace Edge · Remote · Feb 2026 – Mar 2026

Shipped a production AI coaching chatbot for a live eLearning client in 4 weeks by leading a 3-person team, owning the Express/TypeScript API, Turso (libSQL) data layer via Prisma, and Gemini 2.5 Flash integration.
Kept answers based on the client's own curriculum instead of generic AI advice by loading all 20 lesson plans directly into the model's context, with no extra search infrastructure needed.
Kept the chatbot on-topic and safe with a 4-category intent classifier and a safety layer that strips personal information before messages are stored.

Founder & CTO

Advancing Future Innovators (AFI) · Ontario · 2024–2025

Delivered programming education to 30+ students per session by founding a nonprofit and building school partnerships, running operations and volunteer coordination across multiple local schools.

Education

BASc Computer Science (Co-op)

McMaster University · Hamilton, ON · Sep 2025 – May 2029

Beyond Code

Inclusion & Integration Instructor, City of Brampton

2023 to 2025 · I supported campers with autism and Down syndrome in groups of 1 to 3, adapting activities so everyone could take part.

Swim Instructor, Super Swims

2023 to 2025 · I taught one-on-one swim lessons for autistic kids, adjusting to each kid's needs and how they communicate.

Achievements & Extracurriculars

NASA Space Settlement Design Contest · Grand Prize, 2025

Grand Prize out of 9,000+ participants across 12 countries. Presented at ISDC.

MEC Debate · 2nd Place, 2025

Hackathons

The Record (Best Use of ElevenLabs) · SEED (Best UI) · C.A.P.T.C.H.A. (solo)

Activities

Mac AI Club · Engineers Without Borders · Socratica

[ ↓ DOWNLOAD PDF ]

Skills

// LANGUAGES

[ C ] [ PYTHON ] [ JAVASCRIPT ] [ TYPESCRIPT ] [ SQL ] [ PHP ] [ HTML / CSS ] [ HASKELL ]

// FRAMEWORKS & LIBRARIES

[ REACT 19 ] [ ZUSTAND ] [ TAILWIND CSS ] [ NODE.JS ] [ EXPRESS ] [ VITE ] [ PRISMA ] [ LARAVEL ] [ FASTAPI ] [ HONO ]

// TOOLS

[ GIT / GITHUB ] [ GITHUB ACTIONS ] [ CURSOR ] [ LINUX ] [ DOCKER ] [ RAILWAY ] [ STRIPE ] [ JIRA ] [ CLOUDFLARE WORKERS ] [ VERCEL ]

// DATA

[ POSTGRESQL ] [ PGVECTOR ] [ SUPABASE ] [ TURSO ] [ MONGODB ]

// CONCEPTS

[ LLM INTEGRATION ] [ PROMPT ENGINEERING ] [ REST APIS ] [ CI / CD ] [ RAG ] [ VECTOR EMBEDDINGS ] [ GEMINI API ]

// ABOUT

Who I am

Gurehmat Chahal

I'm a Computer Science Co-op student at McMaster and previously co-founded the nonprofit Advancing Future Innovators (AFI).

Outside code I train Muay Thai and BJJ, hike, and love tinkering with PC builds.

4 Companies I've shipped production work for

2 Hackathon awards

9K+ Competitors in the NASA contest I won (Grand Prize)

[ EMAIL ME ]