I'm a Machine Learning Engineer based in Melbourne, currently leading research into the productionisation of an agentic chatbot at FocusBear. I designed and built an agentic AI assistant end to end: from the architecture research the team adopted, through retrieval and evaluation, to live integration with the production backend and the AWS infrastructure it runs on. I hold a Bachelor of Applied Data Science from Monash University.
I care about building ML systems that solve real problems for real users, with a strong preference for code-owned, transparent architectures over black-box platforms.
- LLM applications and agents: retrieval-augmented generation, function-calling agents, prompt engineering, RAG evaluation
- Production ML systems: serverless deployment, infrastructure as code, authentication, testing, architecture documentation
- Healthcare and scientific computing: ICU mortality prediction, molecular image analysis, climate driver modelling
Languages: Python, TypeScript, SQL, R LLM and ML: LlamaIndex, LangChain, LangGraph, OpenAI, HuggingFace Transformers, PyTorch, scikit-learn, RAGAS Retrieval: pgvector, FAISS Backend and cloud: FastAPI, AWS (Lambda, CDK, API Gateway, Secrets Manager, CloudWatch), Docker, PostgreSQL, JWT and OAuth 2.0 Data and viz: pandas, NumPy, Plotly, Tableau, Power BI Tooling: Git, pytest, LocalStack, Streamlit, Google Cloud
Production-shaped AI assistant that answers questions from a knowledge base with cited sources and acts on a user's account through function-calling tools. Features per-user JWT authentication, prompt-injection defence for uploaded documents, lazy serverless initialisation, and an AWS CDK stack with an API Gateway JWT authorizer. A clean-room reimplementation of patterns from my FocusBear work, with a case study covering the decisions behind it.
Bilingual English and Swahili RAG assistant for navigating Nairobi's Matatu network. Built with FAISS, HuggingFace, ChatGroq and deep-translator, with a conceptual offline GPT-2 extension for low-connectivity areas.
PyTorch implementations of RNN, GRU, LSTM and BERT for NLP question classification. Includes a from-scratch RNN built on raw tensor operations, a configurable BaseRNN with multiple pooling strategies, and fine-tuned BERT on the TREC dataset.
Model predicting ICU mortality risk from the five most clinically critical vital signs. Achieved ROC-AUC of 0.75 to 0.82, with an emphasis on interpretability for clinical decision support.
Computer vision pipeline for automated counting and classification of molecule species from STM imaging data. Combined binarisation, blob detection and scikit-learn classifiers to reduce manual inspection effort by 40 to 50 percent.
Descriptive analysis and modelling of climate variables, developed during my CSIRO Aspendale placement, where I analysed post-wildfire atmospheric data and built dashboards and reports that informed research planning.
- Portfolio: stephanie-wainaina-portfolio.lovable.app
- LinkedIn: linkedin.com/in/stephanie-wainaina
- Email: wainaina.stephaniew@gmail.com
Open to Data Science, Machine Learning Engineering, Forward deployed Engineer, AI Engineering and Data Engineering roles.

