David Withnall
Senior Software Development Engineer at Amazon
Australia
Summary
👤
Senior🎓
Top SchoolDavid Withnall is a senior software development engineer with 10+ years building scalable, customer-facing systems from IVR and mobile apps for the Australian Taxation Office to machine learning-driven recommendation and computer vision infrastructure at Amazon. He has led cross-functional teams and end-to-end projects that processed hundreds of millions of products, reduced model training time from months to weeks, and delivered ensemble ranking solutions across 15 global marketplaces. Deeply experienced in Java/Python microservices, AWS ML platforms (SageMaker, Glue, Athena), and data pipelines, he focuses on cost optimization, experiment-driven personalization, and resilient architecture. David combines hands-on implementation with product thinking—he’s driven experiments like Multi-Arm Bandit ranking and active learning tooling that materially improved coverage and business metrics. He also brings a background in voice authentication and high-volume telephony systems, which informs his emphasis on robustness and security in user-facing services. Based in Australia after years in Seattle, he’s known for translating complex ML research into production-quality systems that scale globally.
10 years of coding experience
21 years of employment as a software developer
Bachelor of Information Technology, Software Engineering, Bachelor of Information Technology, Software Engineering at QUT (Queensland University of Technology)
Stackoverflow
53reputation
6kreached
3answers
2questions
Github Skills (18)
cracking8
csharp7
sicp7
generics6
data-structures6
voicexml6
model-view-controller6
ivr6
low-level6
asp-net-mvc6
vxml6
java6
ios6
algorithms5
aws4
Programming languages (3)
Github contributions (3)
careercup/CtCI-6th-Edition-CSharp
Apr 2016 - Apr 2016
Cracking the Coding Interview 6th Ed. Solutions (C# Port)
Contributions:4 commits, 4 PRs, 7 pushes in 1 day
crackingcsharpcracking-the-coding-interview
careercup/CtCI-6th-Edition
Apr 2016 - Apr 2016
Cracking the Coding Interview 6th Ed. Solutions
Contributions:1 issue in 1 day
cppcareercupcracking-the-coding-interviewsicpcompetitive-programming
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