# Harish Kumar Vaithyan Nandhagopu > Actively seeking Full Stack Developer roles | Java, Spring Boot, React, AWS | API & Microservices Expert. Location: San Francisco, California, United States Profile: https://flows.cv/harishkumarvaithyannandhagopu Full Stack Software Engineer with 5+ years of experience designing and scaling cloud-native, event-driven systems for global e-commerce and social media platforms. Proven expertise in backend API modernization, GraphQL migrations, and high-throughput microservices supporting billions of users and large-scale transaction volumes. Strong background in Java and Spring Boot, building secure, PCI-DSS compliant payment systems, real-time data streaming pipelines, and distributed architectures using Kafka, Redis, and gRPC. Experienced in migrating REST APIs to GraphQL, enabling real-time synchronization, improved performance, and developer-friendly APIs. Hands-on experience integrating AI/ML and AdTech pipelines to support personalization, targeted advertising, content moderation, and streaming analytics, delivering measurable improvements in engagement, GMV, and system efficiency. Skilled in building responsive frontend applications and dashboards using React, TypeScript, GraphQL subscriptions, and WebSockets, paired with robust CI/CD pipelines and containerized deployments using Docker, Kubernetes, and cloud platforms including AWS, IBM Cloud, and GCP. Experienced collaborating cross-functionally in high-traffic, production-critical environments to deliver reliable, scalable, and zero-downtime systems. ## Work Experience ### Software Engineer @ Shopify Jan 2024 – Present | San Francisco, CA • Led the successful migration of core commerce APIs from REST to GraphQL, reducing average API response times by 27% and enabling real-time data synchronization across 5.6 million active stores globally. • Engineered scalable Java backend payment gateway architectures (Shop Pay and third-party providers) supporting $18B+ annual transaction volume with full PCI-DSS compliance and zero downtime. • Delivered high-impact AdTech and AI personalization microservices, increasing ad-driven GMV by 22% and boosting customer conversion via real-time recommendations and streaming analytics. • Designed and implemented type-safe, self-documenting GraphQL APIs with Spring Boot and GraphQL Java, covering commerce, media pipelines, payments, and personalization domains. • Built event-driven services powered by Apache Kafka to enable seamless large-scale data streaming for media processing, payment events, and AI recommendation engines. • Developed secure authentication and authorization mechanisms using OAuth2, JWT, and API Gateway hardening to protect sensitive data and enforce fine-grained access controls. • Automated end-to-end CI/CD pipelines using Docker, Kubernetes (GKE), Helm, and GitHub Actions, driving rapid, reliable microservice deployments with zero downtime. • Designed and maintained cloud-native infrastructure on AWS, utilizing EC2, S3, Lambda, and RDS for scalable, secure, and cost-effective backend and media pipeline deployments. • Developed real-time dashboards in React.js using GraphQL subscriptions over WebSockets, delivering live KPIs and AI insights with fast, intuitive data visualization for merchants. • Built responsive, accessible UIs with React, TypeScript, HTML5, CSS3, and Apollo Client, ensuring efficient GraphQL data fetching and seamless user experiences across admin and storefront apps. ### Full Stack Software Engineer @ TikTok Jan 2023 – Jan 2024 | Los Angeles, LA • Drove microservices scalability, reducing API response latency by 30% and improving system reliability to 90% SLA for over 1.6 billion global users, enabling seamless content delivery and monetization. • Engineered AdTech integration features that increased targeted ad revenue by 15% through advanced user segmentation and real-time bidding enhancements, directly supporting $23 billion annual revenue. • Collaborated across cross-functional teams to implement real-time personalization pipelines, boosting user engagement metrics by 22% through intelligent feed ranking and live recommendation updates. • Designed and deployed Spring Boot 3.0 Java microservices, leveraging modular API-first development, containerized with Docker and managed via Kubernetes on AWS for rapid scaling and zero-downtime releases. • Built and optimized distributed event-driven architectures using Apache Kafka, Redis, and gRPC, supporting real-time feed generation, live metrics, and scalable service orchestration. • Integrated AI/ML pipelines (TensorFlow/PyTorch served via Java APIs) for instant content moderation and personalized user experiences, working closely with data science and backend engineering teams. • Enhanced system observability and reliability with advanced monitoring (Prometheus, Grafana), distributed tracing, and CI/CD automation (GitHub Actions, Jenkins), dramatically reducing incident response time. • Developed responsive creator dashboards and web UIs using React.js, TypeScript, HTML5, and CSS3, integrating REST/gRPC APIs for dynamic media management, real-time analytics, and interactive campaign functionality. ### Software Engineer @ IBM Jan 2019 – Jan 2022 | Los Angeles, LA • Assisted in engineering and optimizing core Java microservices using Spring Boot and Kafka for IBM MaaS360, contributing to a 32% reduction in incident response time and supporting secure device policy enforcement for 2,500+ Fortune 1000 enterprises globally. • Supported backend integration of AI-driven threat analytics leveraging IBM Watson APIs, helping automate compliance monitoring and predictive risk scoring to enhance enterprise security and reduce manual oversight. • Developed scalable, secure RESTful APIs and event-driven pipelines using Hibernate (JPA), integrated with IBM Db2, PostgreSQL, and MongoDB databases, aiding adaptive media streaming and content management within a microservices cloud environment orchestrated by Docker, Kubernetes, and CI/CD tools like Jenkins and Tekton. • Collaborated on building and maintaining responsive admin portals using React.js, TypeScript, HTML5, CSS3, and JavaScript, incorporating real-time WebSocket updates to seamlessly connect frontend interfaces with microservicebased Java backends, delivering intuitive administrative dashboards and endpoint analytics. • Analyzed and contributed to the implementation of modern DevOps practices, supporting cloud-native deployments on IBM Cloud and AWS to help maintain zero-downtime releases and high availability for critical Unified Endpoint Management and security services. ## Education ### Master of Science in Information Systems Northeastern University ### B.Tech in Computer Science Shanmugha Arts, Science, Technology and Research Academy ## Contact & Social - LinkedIn: https://linkedin.com/in/harish-kumar-vaithyan-nandhagopu --- Source: https://flows.cv/harishkumarvaithyannandhagopu JSON Resume: https://flows.cv/harishkumarvaithyannandhagopu/resume.json Last updated: 2026-03-29