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I am a results-driven AI professional with over 9 years of hands-on experience delivering scalable, production-ready AI solutions. My expertise spans large language models, recommendation engines, and full-stack systems, with a particular focus on building and orchestrating LLM-powered AI agents using modern tools like LangGraph, LangSmith, and PyTorch. I have a proven track record of driving meaningful business impacts, including boosting e-commerce conversions and user engagement through hyper-personalized recommendations, leading multilingual NLP applications at large scale, and implementing critical machine learning systems such as fraud detection and AI content moderation. I thrive in cross-functional teams and enjoy mentoring engineers while driving innovation from ideation to execution.…I am a results-driven AI professional with over 9 years of hands-on experience delivering scalable, production-ready AI solutions. My expertise spans large language models, recommendation engines, and full-stack systems, with a particular focus on building and orchestrating LLM-powered AI agents using modern tools like LangGraph, LangSmith, and PyTorch. I have a proven track record of driving meaningful business impacts, including boosting e-commerce conversions and user engagement through hyper-personalized recommendations, leading multilingual NLP applications at large scale, and implementing critical machine learning systems such as fraud detection and AI content moderation. I thrive in cross-functional teams and enjoy mentoring engineers while driving innovation from ideation to execution.

David McDuffie

AI Engineer, Developer, Full Stack Developer, +4

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I am a results-driven AI professional with over 9 years of hands-on experience delivering scalable, production-ready AI solutions. My expertise spans large language models, recommendation engines, and full-stack systems, with a particular focus on building and orchestrating LLM-powered AI agents using modern tools like LangGraph, LangSmith, and PyTorch. I have a proven track record of driving meaningful business impacts, including boosting e-commerce conversions and user engagement through hyper-personalized recommendations, leading multilingual NLP applications at large scale, and implementing critical machine learning systems such as fraud detection and AI content moderation. I thrive in cross-functional teams and enjoy mentoring engineers while driving innovation from ideation to execution.…I am a results-driven AI professional with over 9 years of hands-on experience delivering scalable, production-ready AI solutions. My expertise spans large language models, recommendation engines, and full-stack systems, with a particular focus on building and orchestrating LLM-powered AI agents using modern tools like LangGraph, LangSmith, and PyTorch. I have a proven track record of driving meaningful business impacts, including boosting e-commerce conversions and user engagement through hyper-personalized recommendations, leading multilingual NLP applications at large scale, and implementing critical machine learning systems such as fraud detection and AI content moderation. I thrive in cross-functional teams and enjoy mentoring engineers while driving innovation from ideation to execution.

Available to hire

I am a results-driven AI professional with over 9 years of hands-on experience delivering scalable, production-ready AI solutions. My expertise spans large language models, recommendation engines, and full-stack systems, with a particular focus on building and orchestrating LLM-powered AI agents using modern tools like LangGraph, LangSmith, and PyTorch.

I have a proven track record of driving meaningful business impacts, including boosting e-commerce conversions and user engagement through hyper-personalized recommendations, leading multilingual NLP applications at large scale, and implementing critical machine learning systems such as fraud detection and AI content moderation. I thrive in cross-functional teams and enjoy mentoring engineers while driving innovation from ideation to execution.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Intermediate

Work Experience

Senior AI Full Stack Engineer at Simform

November 1, 2023 - Present

Spearheaded the development of LLM-powered AI agents using LangGraph and LangSmith to enable dynamic multi-turn conversations and tool-chaining capabilities for intelligent automation. Built and deployed hyper-personalized product recommendation systems for e-commerce, delivering a 23% increase in conversions and 37% boost in engagement. Designed context-aware orchestration layers with support for memory, API access, and dynamic decision branches. Utilized observability tools such as LangSmith for experiment tracking and continuous performance tuning. Developed user behavior analytics pipelines to personalize shopping journeys and partnered closely with cross-functional teams for low-latency, reliable AI feature delivery. Mentored junior developers and established best coding practices.

AI Engineer at Meta AI

September 1, 2023 - July 25, 2025

Led integration of recommendation engine models into Facebook Feed and Instagram Explore to boost engagement metrics by over 12%. Designed and deployed large-scale NLP models for Messenger enabling smart replies, intent recognition, and multi-turn conversations handling 500 million daily interactions with low latency. Collaborated on vision-language transformers for Instagram Stories and Reels to support content moderation and automatic captioning, improving accessibility compliance by 30%. Developed personalized AI notification systems that improved push notification click-through rate by 18%. Contributed to multilingual LLM chat assistant deployments supporting 15+ languages with human-in-the-loop training. Scaled AI inference for 1B+ users with distributed serving and A/B testing using Meta’s PyTorch/XLM infrastructure.

Machine Learning Engineer at Amazon

December 1, 2020 - July 25, 2025

Developed scalable ML models for Amazon’s recommendation engine, increasing click-through rate by 6.5%. Designed a real-time fraud detection system reducing transaction fraud by 31%. Led hyperparameter tuning framework optimization with Bayesian methods, cutting tuning time by 40%. Built and maintained a feature store improving model onboarding by 30%. Launched ML-powered automated inventory classification improving accuracy by 22%. Implemented end-to-end ML pipelines on AWS reducing deployment time to under 24 hours with CI/CD integration. Enhanced security with OAuth 2.0, JWT, MFA, and rate limiting, cutting unauthorized access attempts by 75%. Authored documentation and led knowledge sharing for ML best practices across business units.

Backend Engineer at Zappos

April 1, 2018 - July 25, 2025

Designed scalable microservices architecture, improving backend performance by 30%. Optimized RESTful APIs and database queries reducing response times by 40%. Introduced asynchronous processing with message queues like RabbitMQ and Kafka for order processing and notifications. Led migration from monolithic systems to cloud-native AWS infrastructure, containerizing services with Docker and orchestrating via Kubernetes. Collaborated with cross-functional teams to deliver features like personalized product recommendations and real-time inventory while maintaining test coverage above 90%.

Software Developer Intern at Zappos

May 1, 2016 - July 25, 2025

Collaborated on scalable RESTful API design supporting customer personalization and order tracking, reducing latency by 20%. Optimized MySQL and DynamoDB queries for data retrieval efficiency. Participated in Agile development cycles contributing to code reviews, unit testing, and CI/CD deployment using Jenkins and Docker.

Senior AI Full Stack Engineer at Simform

November 1, 2023 - Present

Led the development of LLM-powered AI agents supporting dynamic multi-turn conversations and tool chaining, enhancing intelligent automation capabilities. Built and deployed a hyper-personalized product recommendation system that increased e-commerce conversions by 23% and engagement by 37%. Designed context-aware orchestration layers with memory and API access to provide personalized user experiences. Utilized LangSmith for observability and continuous improvement through experiment tracking and prompt evaluation. Developed user behavior analytics pipelines for real-time personalization and conducted extensive A/B testing to optimize recommendation algorithms. Collaborated closely with product, design, and DevOps teams to ensure AI feature reliability and performance, and mentored junior engineers to foster best coding and integration practices.

AI Engineer at Meta AI

September 30, 2023 - August 20, 2025

Led end-to-end integration of recommendation engine models into Facebook Feed and Instagram Explore, achieving over 12% lift in engagement metrics. Designed and deployed large-scale NLP models for Messenger managing over 500 million daily interactions with low latency. Collaborated on vision-language transformers for Instagram content moderation and captioning, improving accessibility compliance by 30%. Developed reinforcement learning-based personalized AI notification systems improving click-through rates by 18%. Contributed to multilingual LLM chat assistant deployment supporting 15+ languages with human-in-the-loop training. Scaled AI inference infrastructure for 1B+ users leveraging internal PyTorch/XLM tools, enabling distributed model serving and streamlined A/B testing frameworks.

Machine Learning Engineer at Amazon

December 31, 2020 - August 20, 2025

Developed scalable machine learning models for Amazon's recommendation engine, improving click-through rate by 6.5%. Designed a real-time fraud detection system with XGBoost and Kafka that reduced transaction fraud by 31% within 3 months. Implemented a Bayesian optimization experimentation framework, cutting model tuning time by 40%. Built and maintained a feature store to enable reuse and prevent data leakage, accelerating model onboarding by 30%. Collaborated on launching ML-powered inventory classification improving accuracy by 22% on long-tail products. Delivered end-to-end ML pipelines on AWS with Lambda, Glue, and EMR, reducing deployment time to under 24 hours. Enhanced security by developing OAuth 2.0 and JWT authentication with multi-factor authentication, decreasing unauthorized access attempts by 75%. Authored documentation and led knowledge-sharing to promote MLOps best practices across business units.

Backend Engineer at Zappos

April 30, 2018 - August 20, 2025

Designed and implemented scalable microservices architectures enhancing backend performance by 30%, enabling seamless frontend and third-party integrations. Optimized RESTful APIs and database queries resulting in 40% faster response times. Introduced asynchronous processing with RabbitMQ and Kafka for order processing and notifications. Led migration from monolithic systems to AWS cloud-native infrastructure via Docker containerization and Kubernetes orchestration. Worked cross-functionally to deliver features including personalized product recommendations and real-time inventory management, maintaining over 90% automated test coverage and high code quality.

Software Developer Intern at Zappos

May 31, 2016 - August 20, 2025

Collaborated on the design and implementation of scalable RESTful APIs supporting customer personalization and order tracking, reducing latency by 20%. Optimized database queries in MySQL and DynamoDB to improve data retrieval efficiency for high-traffic services. Participated in Agile development cycles, performing code reviews, expanding unit test coverage, and contributing to CI/CD pipeline deployments using Jenkins and Docker.