# Randy Ma > Software Engineer | Distributed Systems | Java, AWS | Large-Scale Backend Systems Location: United States, United States Profile: https://flows.cv/randyma Software engineer with 8+ years of experience designing, building, and scaling high-throughput distributed systems. Currently focused on backend and platform systems at Amazon. Recent work & impact - Built and launched multiple 0 → 1 production systems, including a content relevance optimization feature powering high-traffic Amazon ad placements (Fire TV, Prime Video, Fire Tablet) - Designed and operated an end-to-end machine learning pipeline for product recommendations, from data ingestion to model deployment - Own production services with high availability and operational rigor in AWS Technical focus - Distributed systems, backend infrastructure, and data pipelines - Java (primary), Python, JavaScript/TypeScript - AWS, ML systems, production service ownership Open to conversations about backend and platform engineering roles. ## Work Experience ### Software Engineer II @ Amazon Jan 2023 – Present | Sunnyvale, California, United States - Launched a 0 → 1 Ad Content Relevance Optimization feature for Amazon Devices (Fire TV, Prime Video, Fire Tablet), delivering personalized ad recommendations and improving campaign CTR and conversion; scaled systems to 100M DAU, 10K+ TPS, with 99.99% availability and <200 ms latency, generating $20M annual revenue. - Led a team of 5 engineers to deliver the Ad Content Relevance feature end-to-end, designing backend control and data planes, coordinating front-end updates, and overseeing asynchronous ad attribution pipelines; mentored junior and mid-level engineers through pair programming, design reviews, and code reviews. - Drove cross-org collaboration and implementation for a senior vice president-level initiative to optimize Amazon DSP’s (Demand Side Platform) predictive ML models (probability of app download, click, purchase) by 8%. Partnered with Applied Science and DSP engineering teams on feature engineering, model training/evaluation, and online inference. - Designed and implemented an end-to-end ML pipeline for ad recommendations, including raw data discovery, automated data ingestion, and deployment using AWS Glue, Apache Spark, Airflow, and batch inference. - Hosted biweekly office hours to support Device Ads publisher teams, serving as the integration point for metadata retrieval requests and helping 10+ partner teams successfully integrate with or request features on our service. ### Software Engineer @ Amazon Jan 2022 – Jan 2023 | Sunnyvale, California, United States - Engineered a distributed metadata retrieval system in AWS, integrating with retail and video product catalogs to enable metadata enrichment during campaign setup and at runtime for Fire TV, Prime Video, and Fire Tablet placements. Implemented distributed caching (using Memcached) and multi-threading to achieve <20 ms latency at 10K+ TPS. - Launched a closed beta of a content relevance optimization feature for Prime Video display ads by implementing service-level integrations with our ad personalization system and conducting A/B testing to gradually roll out the feature to users. - Collaborated across teams to deliver new features for Fire Tablet and Alexa placements, including enabling early filtering of ads based on content restrictions and adding enrichment changes to support new placement launches (e.g. Fire Tablet display ads, Alexa skill ads) ### Software Engineer @ PayPal Jan 2020 – Jan 2022 | San Jose, California, United States Risk Payments Platform - Built high-availability (99.5%) Java/Spring Boot ML model hosting infrastructure delivering real time fraud predictions, preventing $60M in potential monthly losses. - Implemented a Tier 0 risk evaluation checkpoint using rules and distributed caching (Memcached) to achieve <10 ms latency for real-time risk assessment. - Engineered horizontally scalable data and model-serving pipelines, increasing throughput 10× to support more complex models and higher inference volumes. ### Business Intelligence Engineer @ Oracle Jan 2019 – Jan 2020 | Santa Clara, CA Full-stack web development to automate & enhance supply chain processes Built and maintained ETL processes to support Supply Chain ### Software Engineer @ Walmart Labs Jan 2017 – Jan 2019 | Bentonville, AR Owned backend web services for large, Tier 1 applications including an MQTT push notification service and Single-Sign-On service Full-stack development of single-page web application used by business ops teams Built data pipeline for processing associate clock data across US ## Education ### BS in Computer Science The Johns Hopkins University Jan 2012 – Jan 2016 ### Monta Vista High School Jan 2008 – Jan 2012 ## Contact & Social - LinkedIn: https://linkedin.com/in/randyma12 --- Source: https://flows.cv/randyma JSON Resume: https://flows.cv/randyma/resume.json Last updated: 2026-03-22