Portfolio: Ryan.Zernach.com • Email: Ryan@Zernach.com •LinkedIn • GitHub • Remote • FinTech + Healthcare
- Distributed systems engineer with 10+ years of engineering Payments, Agents, Mobile Apps, Websites, DevOps + MLOps Systems
- Scaled CellarChat™ tool-calling agent to 1M+ active members, complete with RLHF & CI/CD LLM evaluation scoring pipelines
- Engineered Apple Pay subscriptions to lift recurring revenue by 25%+ which lifted mobile app ratings to 4.9★ (10k+ reviews)
- Completed Gauntlet AI engineering fellowship with 2% acceptance rate and mastered the art of Cursor + Claude + Codex
- Designed observable backend systems that support autonomous AI-powered VoIP eCommerce payment automations
- Awarded Top 10 of 10,000 international projects in 2024 NASA Space Apps hackathon with AI Voice Assistant
| Category | Technologies |
|---|---|
| Programming Languages | TypeScript, Python, Rust, Golang, Java, C#, Ruby, Swift, Kotlin, Bash, JavaScript, PHP, C++, Objective-C, R, Solidity, Dart, Flutter, XML |
| AI Systems + Machine Learning | LLMOps, vLLM, LiteLLM, RAG, Agents, MCP, Vector Embeddings, Evaluations, Semantic Kernel, LangChain, Langfuse, Computer Vision, PyTorch, Knowledge Graphs, TensorFlow, Scikit-Learn, Bedrock, Foundry |
| Platform + Backend Engineering | DevEx, Node.js, FastAPI, Django, Nest.js, Express, .NET Core, OpenAPI, Microservices, REST, GraphQL, WebSockets, Webhooks, gRPC, Kafka |
| Data + Persistence | PostgreSQL, SQL, NoSQL, Redis, Vector Databases, ETL, Snowflake, Graph Databases, Entity Relationships, Caching, BigQuery, PySpark |
| Cloud Infrastructure + DevOps | AWS, Azure, GCP, Cloudflare, Docker, GitHub Actions, Terraform, Kubernetes, CI/CD, CloudOps, Blue/Green, DNS, Networking |
| Front-End + Product Engineering | React, React Native, iOS, Android, Web, Swift, Kotlin, Flutter, Expo Router, Next.js, Redux, Streamlit, Animations, Design, User Feedback, Playwright |
| Distributed Systems + Operations | Queues, Redis, RabbitMQ, Analytics, Pub/Sub, Linux, Airflow, VoIP, Cron, WebRTC, Observability, OpenTelemetry, Rate Limiting, Horizontal Scaling, Machine Learning CI/CD, Event-Driven Architecture, Load Balancing |
| Security, Identity + Compliance | AuthN, AuthZ, OAuth, HIPAA, SOC 2, Identity, Role-Based Access Control, JWT, Secure Systems Design, SSO, API Security, Secrets Management |
| Payments, Communications + Integrations | PCI Compliance, Stripe, Apple Pay, IAP, Billing, Subscriptions, Wallets, Twilio, SMS, Push Notifications, HTTP APIs, Marketing Tech, SMTP/IMAP |
| Blockchain + Web3 | Ethereum, Solana, dApps, WalletConnect, MetaMask, Polygon, Solidity, Smart Contracts, Ethers.js, Tokens, ERC-20, ERC-721 |
- Building agentic products and back-end systems across Python, Typescript, vector embeddings + OSS large-language models
- Automated eCommerce marketplace by using MCP, Claude/ChatGPT integration, Twilio VoIP realtime voice agents + DALL-E
- Containerized scalable Robotic Process Automation (RPA) via OpenAPI middleware, local vLLM, web scraping + Kubernetes
- Published TranslateWallpaper™ mobile app for travelers pronounce words via LLM-generated wallpaper cheatsheets
- Scaled agentic CellarChat™ to 1M+ international members & built world’s highest-rated #1 wine app
- Architected RLHF pipeline to fine-tune OpenAI’s GPT-4o, OpenAPI CI/CD triggers, embeddings, & evals
- Integrated ML wine recommendations using Azure-ML + world’s largest online database of wine reviews
- Maintained Python, TypeScript, React Native, C#/.NET, SQL, Redis, CI/CD, Azure AI Foundry + PromptFlow
- Helped to boost app store ratings to 4.9★ average with 10,000+ verified 5-star ratings on iOS and Android
- Embedded Apple Pay subscriptions in the React Native app to generate additional 25%+ recurring revenue
- Developed backend Python MCP server supporting agentic tooling, account management + support tickets
- Improved user’s experience of cellar management CRUD workflows to improve consistency and reduce taps
- Implemented PyTorch OCR image-to-text search, high-performance barcode scanning, and activity feed posts
- Streamlined the Redux middleware for fast global state management and persistence between user app sessions
- Rebuilt the React Native app’s analytics implementations for tracking critical user interactions and in-app behavior
- Arranged A/B tests during paywall + onboarding experiences using phased rollout schedules for marketing analysis
- Migrated 25+ year old legacy support ticket system from Active Server Pages (ASP) to TypeScript Express framework
- Productionized stocks/crypto exchange to compete with Robinhood: public leaderboards + copy friend’s portfolio distribution
- Used AWS Terraform to deploy docker container running, Java + Springboot, & NodeJS dashboards, and SQL migrations
- Constructed core mobile app functionality: Plaid integration middleware, trending investors + suggested stocks
- Built social network features, such as direct chat, user profiles, posts, likes, emojis, & threaded comments
- Wrote the data-visualization logic for viewing and comparing the performance of different stocks/crypto
- Transitioned eSports React Native codebase from JavaScript to TypeScript for long-term maintainability
- Improved Ruby on Rails for push notifications, chat, & native calendar sync to improve user satisfaction
- Remedied hardware’s bluetooth transactions in Swift telecommunications app + Python Flask app
Data Science + Machine Learning Tutor • edX • Vanderbilt, UC Berkeley, +24 others • Remote July 2020 – Sept 2021
- During pandemic, taught 900+ post-grad students machine learning, Python, PyTorch, APIs,, TypeScript, SQL + databases
- Managed busy schedule of remotely teaching 30+ university students per week in 1:1 setting (one hour per person)
- Dozens of universities were subscribed to my employer’s curriculum and online tutoring resources for students
React Web Developer + Landscape Designer • Georgia Hybrid Landscaping • Alpharetta, Georgia Feb 2013 – Jan 2019
- Engineered uploading videos/images, survey questions, pricing proposals, and processing payments with BrainTree
- Migrated websites from PHP to NodeJS React, which helped the business process more than $1M+ gross sales
- Managed online eCommerce payments, analytics, Google AdSpend, and logistics of bulk material deliveries
- Configured automated, outbound marketing email campaign schedulers and listeners using IMAP/POP
- Designed industry-best customer experiences with 2D/3D graphic designs and optional add-ons
- Designed residential and commercial landscape plans for hardscapes, lighting, drainage, plants
Payments Systems Intern (Card Processing) • Cost Plus Processing • Alpharetta, Georgia Sept 2012 – Jan 2013
- Worked with merchant processing systems & payment gateways to understand PCI compliance and financial flows
- Analyzed end-to-end card transaction lifecycles (interchange rates, risk) across critical payment networks
- Built foundational knowledge of secure payment infrastructure, interchange fees, & transaction routing EDUCATION + TRAINING
- Mastered how to command agents, automate workflows, and 100x enterprise-grade software engineering
- Harnessed the power of RAG, multi-agent systems, OpenAPI, MCP, Cursor, Claude, Codex, vLLM
- Recommendation Engines, Computer Vision (CV) Models, Time-Series Forecasting, Natural-Language Processing
- Python, SciKit-Learn, PySpark, Django, Flask, FastAPI, Data Engineering, PostgreSQL Databases, Back-End APIs
- Design Principles, Science of Grass, Outdoor Business Management, Landscape Architecture
- Visual Basic, Calculus, C, C++, R, Statistics, Data Structures, Programming Principles, Linear Regression
- 2025 • Gauntlet AI Engineering Fellowship (G3)
- 2024 • NASA Space Apps Hackathon Finalist
- 2022 • Blockchain Hackathon Participant
- 2020 • TensorFlow Computer Vision
- 2020 • AutoML Pipelines (DataRobot Academy)
- 2019 • Google Cloud Platform GCP Developer
- 2019 • AWS Microservices Cloud Practitioner
- 2019 • Y Combinator Startup School