Karthikraj Sivakumar

Software and AI engineer.I build things people actually use.

Currently at Trax, working on AI systems for compliance. CS @ NUS, graduating 2027.

See the workRead CV

About

I am a computer science student at NUS, spending this year in Toronto at Trax, a regtech startup building tools for Canadian building codes. I work on the AI side: a system that checks a permit application against a municipality's requirements and flags what it has not answered, for the firms preparing permits and the officials who have to review them.

Before that I was at Perfingo, building the group expenses feature in their app, where the hard part was splitting a bill across currencies and having it still come out exact.

I also co-founded NUS Computing's first AI society, and spent a year as its vice president.

Both jobs come down to the same thing. I like work where roughly right is not good enough.

Things I work with

  • Python
  • Node.js
  • TypeScript
  • FastAPI
  • PyTorch
  • PostgreSQL
  • LangChain
  • Redis
  • Qdrant
  • React
  • Celery
  • Flutter
Karthikraj Sivakumar, standing on a snowy mountain road

Work

Trax

Software engineer

Since 2026

  • Built an AI pipeline that audits building-permit submissions against municipal checklists, with hybrid retrieval over Qdrant and Meilisearch and LLM verdicts cited to the page. Piloted with the City of Kitchener.
  • Built the eval harness and grading engine with our in-house architect, taking verdicts to 84% accuracy on 25 cases. It replaced spot-checks as the team's release signal.
  • Moved analytics onto a first-party Snowplow, Redis Streams and PostgreSQL pipeline, so the admin dashboard makes no third-party calls at runtime.

Perfingo

Software engineer

2025

  • Built multi-currency group bill splitting end to end, one of the app's flagship features, across a Flutter app and a Node, TypeScript and DynamoDB backend.
  • Built the splitting engine and a materialised net-balance model, so splits sum exactly across 16 currencies and a settlement lookup is one read.
  • Built a versioned terms and conditions platform, so legal copy ships without an app-store release.

NUS Computing AI Society

Co-founder, vice president

2024-25

  • Founded the school's first AI society, grew it past 150 members, and ran a 10-person committee across workshops, hackathons and industry partnerships.

Projects

The Snitch logo

Snitch

Hack the North 2026, 2nd in the GPTZero track

A review tool for remote interviews. It flags moments worth a second look using AI-text detection, a check of answers against the CV, speaking rhythm, and visual canaries only an AI assistant would read. The call stays with the recruiter.

  • Next.js
  • FastAPI
  • GPTZero
Demo Code
CAPTCHA recognition model predictions

CAPTCHA recognition

Running live on Hugging Face

A ResNet-style CNN with a BiLSTM head and CTC loss, reading character sequences of unknown length. Fourteen iterations took sequence accuracy from 35% to 55.6%.

  • PyTorch
  • OpenCV
Demo Code
The Klingon Heads translation app

Klingon Heads

Apollo 11, Orbital's top tier

Transformer and GRU sequence-to-sequence models fine-tuned for English and Klingon translation, served through a React and Firebase app with quizzes and flashcards.

  • PyTorch
  • React
  • Firebase
Live site Code

Everything else

  • Minimart@MWHA token store for Muhammadiyah Welfare Home, where residents earn tokens for good habits and spend them on real items.Hack4Good, 2025LiveCode
  • HealthrixA triage app and monitoring device for cutting clinic waiting times.NUS Health Hack, semi-final, 2024Code
  • DargoBotA Discord bot for a Singaporean YouTuber's community, running games and daily questions.Side project, 2023Code
  • LetsMakan BotA Telegram bot that runs group food orders and splits the cost.Side project, 2024Code
  • MediBase3A Java CLI for tracking patient records, with duplicate detection and input validation.CS2103T, 2024LiveCode
  • Habit TrackerA Flutter app for daily habit logging, with streaks and trend charts.Side project, 2024Code
  • CrimeWhereRandom forest models flagging crime hotspots to help plan patrol routes.LifeHack, 2024Code
  • PayWiseA mobile app for picking the credit card that maximises rewards per purchase.iNTUition, 2023Code

Outside

I was vice president for cycling at NUS Outdoor Adventures, where I planned and led eight night routes across Singapore for groups of thirty or more, owning route safety and on-road support. Most of my time away from a screen still goes to bikes, trails and mountains.

Sitting beside a gravel bike on a woodland trail
At a mountain summit part-way through a hike
Standing on a rock at the edge of a mountain lake

Open to 2027 new-grad software and AI engineering roles

skarthikraj0207@gmail.com
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