David Marshall

David Marshall Senior Full Stack Engineer- Summary Senior Full Stack Engineer with 9+ years of experience building scalable web, blockchain, and AI/ML systems across media & content platforms, fintech/crypto exchanges, Web3/NFT marketplaces, AI product studios, and warehouse automation. Strong hands-on expertise in JavaScript, React, Node.js, Java, PostgreSQL, MongoDB, AWS, and OpenAI APIs. Hands-on experience in system architecture, end-to-end product delivery, smart-contract development, real-time platforms, CI/CD, performance optimizations, compliance integrations, data-driven features that measurably reduce operational costs and accelerate time-to-market, and mentoring engineering teams. Technical Skills Program Languages: JavaScript (ES6+)/TypeScript, PHP, Python, Go, Java, HTML5/CSS3 Frontend Frameworks & Libraries: React/Next.js, Vue.js/Nuxt.js, Angular, React Native Backend: Node.js, Express.js, NestJS, Laravel, Django, Spring Boot API & Integration: REST & GraphQL APIs, JWT, OAuth2, OpenAPI, WebSockets Databases: MySQL, PostgreSQL, MongoDB, DynamoDB, SQLite, Prisma, Firebase Blockchain: Solidity, Smart Contracts, NFT Marketplaces, Token Bridges AI & ML: OpenAI API, VAPI, Twilio, Voice AI Cloud & DevOps: AWS, Azure, GCP, Docker, Kubernetes, Terraform, GitHub Actions, Jenkins Testing & QA: Jest, Mocha, Jasmine, Cypress, Postman, TDD & BDD Version Control & Project Management Tools: Git, GitHub, GitLab, Bitbucket, Jira, Trello, Asana Professional Experience Senior Software Engineer 03/2024 - 08/2025 Cimpatico Studios | United States | Remote    Led development of an AI-powered content studio using Next.js, TypeScript, NestJS, and OpenAI APIs, delivering APIs and auth systems on AWS that cut authoring time by 45% and boosted content throughput. Architected a scalable media processing microservice with Node.js, Docker, FFmpeg, S3, CloudFront, and Redis, lowering infrastructure costs by 25% and accelerating job time from 18s to 7s. Delivered a real-time collaborative editor with GraphQL subscriptions, Prisma, PostgreSQL, and Redis pub/sub, enabling 200 concurrent users with under 150ms update latency.  Strengthened release reliability by implementing CI/CD pipelines with GitHub Actions, Jest, and Cypress while adding rollback procedures, cutting production incidents by 70%. Senior Software Engineer | AI Engineer 03/2021 - 02/2024 Vaultoro | London, UK | Remote     Optimized low-latency trading APIs in Node.js and PostgreSQL with Redis caching, shortening order latency by 35%. Built and deployed a machine learning anomaly-detection pipeline in Python with scikit-learn and FastAPI, lowering false positives by 45% and reducing triage effort by 60%. Integrated blockchain custody and reconciliation services with Ethers.js and scheduled jobs, eliminating 80% of manual work and enhancing settlement accuracy. Migrated legacy systems to containerized microservices on Docker, Kubernetes, Terraform, and CI/CD pipelines, enabling deployments under 20 minutes compared to multi-hour releases. Blockchain Developer | Full Stack Developer 01/2018 - 12/2020 Fayre Labs | London Colney, UK | Remote     Designed, audited, and deployed ERC-721 and ERC-1155 smart contracts in Solidity with Hardhat and OpenZeppelin, securing minting pipelines for large NFT collections. Delivered a full-stack NFT marketplace using React, Node.js, and MongoDB, integrating MetaMask wallet support and off-chain indexing that enhanced reliability and query performance. Built cross-chain bridge prototypes with Solidity smart contracts and Node.js relayers, increasing transfer reliability and lowering error rates. Streamlined smart-contract workflows by automating CI/CD with Hardhat tests and gassaving optimizations, decreasing average minting gas usage by 30%. Software Engineer 12/2014 - 11/2017 AutoStore™ | Singapore | Onsite     Developed inventory and order management services with Java, Spring Boot, and PostgreSQL that handled large SKU sets and raised warehouse order throughput. Constructed a telemetry ingestion pipeline with MQTT, Kafka, and Java consumers, trimming end-to-dashboard latency by 40%. Designed monitoring dashboards with Angular and WebSockets that accelerated issue detection threefold and \minimized downtime. Enhanced release quality by introducing CI with automated integration tests, raising test coverage and reducing regression defects by 50%. Education National University of Singapore | Singapore Bachelor of Science in Computer Science 08/2010 – 10/2014