Sarah Williams

Ruby on Rails, FastAPI, React.js, Remix, PostgreSQL, RSpec, GitHub Actions, Heroku, Docker, Redis, OpenAI API

• Led a core rewrite of the company’s multi-tenant e-commerce platform, transitioning from a monolithic Rails app to a modular architecture using Rails Engines and FastAPI microservices, improving deployment independence and scalability across services.
• Designed and integrated a product categorization engine powered by OpenAI, using GPT API + vector search with Redis, reducing manual tagging by 65% and boosting internal catalog efficiency.
• Developed and maintained key customer-facing features using React.js with Remix for SSR capabilities, achieving >90 Lighthouse performance and accessibility scores.
• Designed CI/CD pipelines using GitHub Actions, Heroku Pipelines, and Docker, reducing production deployment time from 20 to under 5 minutes.
• Spearheaded performance tuning across backend services using PostgreSQL query optimization, Redis caching, and refactoring of N+1 queries, improving page load time by 50%.
• Championed a robust test suite with RSpec and introduced integration testing strategies for React components, increasing confidence in releases and maintaining 95%+ test coverage.
• Mentored junior and mid-level engineers on architectural principles, scalable code patterns, and clean Git workflows; reduced post-deployment bugs by 40%.

Ruby on Rails, Flask, React.js, PostgreSQL, GraphQL, Sidekiq, Docker, AWS, RSpec, PyTest

• Engineered scalable order and inventory systems using Rails and Flask microservices backed by PostgreSQL and Redis, handling millions of monthly transactions and concurrent updates.
• Created dynamic storefront UI components using React.js, consuming GraphQL APIs with Apollo Client, enabling real-time price and stock visibility for users.
• Built and integrated internal tools for marketing and analytics with automated background processing using Sidekiq, supporting custom email workflows and campaign tracking.
• Developed and enforced TDD practices with RSpec (backend) and PyTest (supporting services), achieving 90%+ test coverage across systems.
• Enhanced CI/CD deployment workflows with Docker containers deployed to AWS ECS using GitHub Actions; integrated Sentry and CloudWatch for observability.
• Collaborated cross-functionally with design and product teams to convert business requirements into production-ready code within biweekly Agile sprints.

Ruby on Rails, React.js, LeafletJS, PostgreSQL, Bootstrap, Docker, Jenkins, RSpec, Redis

• Built a city-scale geospatial asset tracking system for public signage and permit workflows using Ruby on Rails backend, React + LeafletJS frontend, and PostgreSQL with PostGIS for spatial data.
• Engineered map-based interfaces for real-time infrastructure monitoring with AJAX, Bootstrap, and Leaflet layers, used daily by 100+ field agents and inspectors.
• Led backend optimization by refactoring legacy logic into service objects, improving response times for API endpoints by 40% and enabling easier testing and modular development.
• Integrated job queuing systems using Redis + Sidekiq for processing background data syncs and notification triggers, ensuring near real-time updates on infrastructure changes.
• Built Docker-based staging environments and CI pipelines with Jenkins, automating linting, testing, and production packaging for both frontend and backend components.
• Contributed to security audits and implemented RBAC and audit logging features to comply with public sector data policies.

Ruby, Java, React.js, MySQL, REST APIs, Jenkins, Bootstrap, Minitest

• Developed full-stack modules for telecom billing and CRM systems, utilizing Ruby and Java backend services with a MySQL datastore and REST API integrations across subsystems.
• Delivered multiple customer support dashboard components using React.js and Bootstrap, streamlining issue triage and SLA monitoring.
• Built backend services to ingest and validate large-scale customer usage logs, leveraging async job processing and batch optimization for high-throughput environments.
• Established a suite of Minitest and unit tests and integrated them with Jenkins-based CI pipelines to support frequent deployments across global teams.
• Worked directly with DevOps and QA teams to troubleshoot production bottlenecks, optimize service logs, and streamline UAT cycles across teams.
• Participated in weekly architecture reviews, shared deployment postmortems, and authored internal documentation for data pipeline workflows.