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Colin O'Connor

@colinoconnor

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Senior Machine Learning Engineer delivering reliable, cost-efficient production ML and GenAI systems.

Ireland

Message

What I'm looking for

I want to build and operationalize reliable, cost-efficient ML/GenAI systems in regulated or enterprise environments with strong engineering practices and measurable business impact.

I am a Senior Machine Learning Engineer with ~8 years building and operating production ML systems across healthcare, logistics, and enterprise AI platforms. I combine deep ML expertise (classical ML, deep learning, LLMs) with strong software engineering and system design skills to ship measurable business impact.

My work focuses on reliability, latency, and cost efficiency: defining SLOs/SLIs, progressive delivery, throughput-aware batching, and targeted model acceleration to reduce incidents and serving costs. I have improved latencies and reduced incidents and compute spend through practical production optimizations.

I have led end-to-end projects including hybrid retrieval/RAG systems, LLM evaluation pipelines, and feature-store patterns, and I routinely operationalize models with CI/CD, monitoring, and audit-ready documentation for regulated environments. I mentor teams, contribute to hiring, and run blameless incident response and postmortems.

I seek to deliver robust, auditable ML systems that balance quality, cost, and compliance while translating technical capabilities into product and customer value.

Experience

Work history, roles, and key accomplishments

Current

Senior Machine Learning Engineer

Current

Fiddler AI

Nov 2024 - Present (1 year 4 months)

Owned reliability, performance, and productization of LLM and model-observability services, cutting serving incidents ~41% and improving p95 latency from ~620ms to ~380ms while reducing compute spend via batching and inference optimizations.

Observability LLM PyTorch Kubernetes Triton ONNX Runtime Prometheus Datadog

Machine Learning Engineer

Merantix Momentum GmbH

Feb 2022 - Oct 2024 (2 years 8 months)

Led design and deployment of production ML systems (search, recommendation, document understanding), improving top-1 retrieval ~11% and reducing p99 latency ~37% via compression and inference-path optimizations.

PyTorch Faiss Kubernetes Spark Kafka MLFlow RAG Model Compression

Data Scientist

Sendcloud B.V.

Dec 2019 - Jan 2022 (2 years 1 month)

Owned data-science initiatives for checkout and shipping, increasing checkout conversion ~6% and reducing carrier spend ~7% by shipping delivery-time predictions and constraint-aware decisioning.

Causal Inference Pyspark BigQuery XGBoost A B Testing Experiment Design

Researcher – Machine Learning

Corti

Jun 2018 - Nov 2019 (1 year 5 months)

Researched and productionized real-time speech and NLP models for a healthcare AI assistant, reducing ASR error ~17% and improving real-time p95 latency from ~420ms to ~240ms via inference optimizations.

PyTorch Calibration Docker Kubernetes Slice Evaluation MLFlow

Software Engineer Intern

EdgeTier

Feb 2018 - May 2018 (3 months)

Improved dashboard responsiveness (p95 900→380ms) and reduced peak error spikes ~60% by query optimizations, pagination/backpressure patterns, and replay tooling for performance testing.

Python SQL Performance Profiling Docker PostgreSQL ETL Testing Debugging

Education

Degrees, certifications, and relevant coursework

Maynooth University

Master of Science, Computer Science

2018 - 2020

Completed a Master of Science in Computer Science with coursework and projects focused on machine learning and applied AI, completed between September 2018 and May 2020.

Maynooth University

Bachelor of Science, Computer Science

2014 - 2018

Completed a Bachelor of Science in Computer Science with foundational coursework in programming, algorithms, and data structures from September 2014 to May 2018.