Data Scientist · ML & Analytics · Sydney

Nadun
Chandrabahu

I build and evaluate machine learning and AI systems, and work with data through analysis and visualisation. I also build websites, web apps, and mobile apps.

currently in Sydney, open to data science roles
profile.jpg
Nadun Chandrabahu
// about

A short version

I'm a data scientist in Sydney with a Master of Data Science from Macquarie University. My work runs from data analytics and visualisation, through statistical modelling on large datasets, to building and evaluating machine learning and AI systems. I also design and build websites, web apps, and mobile apps.

I came to data science from mechanical engineering, which is where the comfort with maths and the habit of measuring things carefully come from. I like problems where the data is messy and the answer matters, and I tend to build something to solve them rather than leave them on a slide.

FocusLLM evaluation, machine learning, and statistical modelling
BaseMacquarie Park, Sydney NSW
EduMDataSci (Macquarie) · BEng Hons Mechanical (Curtin)
NowOpen to data science and analytics roles
// git log --oneline

The path so far

A commit history of the education and work that got me here, newest first.

HEAD → maina3f9c212026contract

AI Engineer

Hatch
Evaluated agentic AI for e-commerce: traced agent reasoning, caught reward hacking, and tuned prompts for reliability.
7b12e0d2024 — 2026freelance

Data Quality Analyst

DataAnnotation
Freelance AI training-data work across audio and mathematics to improve model quality.
c4e81af2023 — 2024on-call

Hardware & Systems Consultant

Azzureo
Maintained server infrastructure and relocated an entire server network between two Sydney sites.
f09d5b22023 — 2025degree

Master of Data Science

Macquarie University
Clinical NLP, statistical modelling, and machine learning. Major project graded 82 (Distinction).
1ab77c92021 — 2022

Operations & Administration

Island Aquarium
Ran live-export logistics to 7 countries, supervised a packing team, and built the company website and tooling.
5d3e0f12020 — 2021

Management Trainee

KIA Motors Lanka
Coordinated workshop operations and built a live vehicle-tracking tool in Google Apps Script, adopted by the branch.
b62a4d82016 — 2017internship

Automotive Technician Intern

DIMO Lanka (Bosch Service)
360 hours of hands-on mechanical, hydraulic and electrical repair work.
e10c93a2014 — 2020degree

BEng (Hons.) Mechanical Engineering

Curtin University · SLIIT
Thesis on the thermal and optical properties of tin-oxide nanoparticles.
0f0a1c42002 — 2014root

Lyceum International School, Wattala

Cambridge O & A Levels
Full schooling through to A Levels. Ranked 3rd island-wide in Computing.
// experience

Work experience

The roles behind the timeline, in a little more detail.

AI and analytics visualisation

AI Engineer

Apr — Jul 2026
Hatch · Contract · Remote
  • Evaluated agentic AI on multi-step e-commerce tasks and measured how much results depended on prompt phrasing.
  • Traced agent reasoning to catch reward hacking, and ran prompt engineering to make agents more reliable.
Agentic AIPrompt engineeringEvaluation
Mathematics equations on a chalkboard

Data Quality Analyst

2024 — 2026
DataAnnotation · Freelance · Remote
  • Created 200+ custom audio clips to train and improve speech and voice recognition models.
  • Wrote worked solutions for 150+ mathematical problems used in AI model training.
NLPAudioData quality
Server rack with network switches and cabling

Hardware & Systems Consultant

2023 — 2024
Azzureo · Sydney & Parramatta
  • Maintained server hardware and components across two Sydney offices.
  • Relocated the company's entire server network between sites, including the setup code to bring it back online.
InfrastructureSystems
Island Aquarium website

Operations & Administration

2021 — 2022
Island Aquarium · Sri Lanka
  • Ran live-export logistics to 7 countries and supervised around 20 packing staff each week.
  • Built the company website (WordPress, then hand-coded) and a custom Excel invoicing tool.
OperationsWebTooling
KIA vehicle-tracking tool in Google Sheets

Management Trainee

2020 — 2021
KIA Motors Lanka · Sri Lanka
  • Coordinated workshop and office operations to keep vehicle repairs on schedule.
  • Built a live vehicle-tracking tool in Google Apps Script that the branch adopted, cutting status-check calls.
CoordinationApps Script
// skills

Tools & areas

Languages & libraries

Machine learning & AI

LLM fine-tuning Model benchmarking Agentic AI evaluation Prompt engineering Hugging Face Transformers NLP Zero / few-shot

Statistics & analytics

Logistic regression Generalized linear models Statistical inference Feature selection Exploratory data analysis Power BI Tableau Quarto
// selected work

Projects

A mix of research, machine learning, and things I have built end to end.

Medical data analytics with AI
Research / NLP

Empowering Medical Data Analytics with AI

My master's major project (Team, graded 82 / Distinction) on getting language models to disambiguate clinical abbreviations. I owned Task 1: framing it, cleaning the CASI dataset of ~26,500 clinical notes, and building the BERT and BioBERT baseline the team measured against.

PythonHugging FaceBERT / BioBERTGPT-4.1
baseline established → GPT-4.1 nano ~48.7% accuracy
Hack 2025 team at Global Recordings Network, Sydney
Machine learning / Speech

Language ID for Endangered Languages

Built at a hackathon for Global Recordings Network, who catalogue audio in thousands of rare languages. Full fine-tuning of Meta's 4,000-language speech model needed ~370GB RAM and 7 hours per epoch, so I trained a light classifier head on embeddings from the frozen encoder instead.

PyTorchMeta MMSColab TPUTransfer learning
confidence 0.89 → 0.991
Financial markets data
Statistics / Modelling

Predicting Mortgage Defaults

A full modelling project in R on Fannie Mae loan data: 420,000+ loans and 75 raw fields. I engineered a binary default target, then cut the fields to a 13-predictor logistic regression using backward stepwise selection on AIC, handling multicollinearity along the way. Delivered as a reproducible Quarto report.

RtidyverseQuartoLogistic regression
75 fields → 13-predictor model · 420,000+ loans
PICKL HQ storefront
Full-stack / E-commerce

PICKL HQ

A pickleball-gear storefront I designed and built end to end. It's a headless setup built with Lovable, wired to Shopify's Storefront API and hosted on Cloudflare, with the brand, product system, and architecture all mine.

LovableShopify APICloudflare
live in pre-launch · ~200 visitors / week
Devotional app on a phone beside an open Bible
Mobile / Full-stack

Grow365

A complete devotional mobile app I built as sole developer for a ministry, in React Native (Expo) with a Supabase backend. I handled all the engineering and the full build pipeline through to a tested Android build; the content comes from the ministry.

React NativeExpoSupabaseEAS
complete build · in testing
Abstract coloured bokeh lights
Research / Writing

Multi-Instance Learning: A Survey

An academic survey on Multi-Instance Learning, a weakly-supervised approach where models learn from group-level labels instead of labelled individual points. It maps the main families of methods and reviews published object-detection work including WSDDN and MIL-SERBoost.

ResearchTechnical writingWeakly-supervised ML
14 sources · LNCS format

Earlier builds

Where I first learned to build for the web. Small, but each one taught something.

Today I Learned
React + Supabase CRUD app
UI Element Library
Pure-CSS component set
Omnifood
Responsive HTML / CSS / JS site
Dice Game
DOM manipulation practice
// contact

Get in touch

Open to data science and analytics roles, and happy to talk through any of the work above.

nadun.c.97@gmail.com
Macquarie Park, Sydney NSW · Australia