# Ricardo Kreyhsig

> Senior Full-stack Engineer @github

Location: Washington DC-Baltimore Area, United States
Profile: https://flows.cv/ricardokreyhsig

Senior Full-stack Engineer with 13+ years of experience on the Web, specializing in modern backend development with Ruby on Rails and Node.js, as well as client-side technologies such as React.js, GraphQL, and TypeScript. Driven by continuous improvement, I am looking for an Agile software organization where I can use my skills to contribute as a Full-stack Engineer.

Motivated by curiosity and ambition, I decided to pursue a long-time passion that was discovered in a programming class in High School.  After successfully graduating from the University of Maryland in Computer Engineering, I started working in programming professionally and have never stopped since.

At the moment, I am working as a Principal Software Engineer at Code for America, where we are revolutionizing tax filing.  On the side, I like to build projects to stay current and hone my skills.

In my free time, I volunteer at a local church. I recharge by spending time with loved ones. I love to sing, play guitar, exercise, and play soccer.  

Technologies: Ruby, Rails, Sorbet, TypeScript, React.js, Node.js, AWS (EC2, S3, SQS, λ), Heroku, Git, SQL, RESTful APIs, GraphQL, Testing, Docker, JSON, HTML, CSS.

Interests: RESTful APIs, Microservices, Design Patterns, CI/CD, Architecture

GitHub: github.com/rickreyhsig
You can reach me at: rickreyhsig@gmail.com

## Work Experience
### Senior Software Engineer @ GitHub
Jan 2024 – Present | Washington DC-Baltimore Area
● Led technical implementation of Dependabot malware detection across 20M+ repositories, expanding security coverage beyond CVE-based alerts and targeting GA launch (Mar 2026)
● Primary technical contact for Microsoft ADO Innersource integration, influencing core Advisory DB data model decisions and onboarding Microsoft engineers — enabling proprietary advisories across 30K+ repositories.
● Served as DRI for 4 new REST API endpoints enabling enterprise repository access management for Dependabot, including pagination support, preventing timeouts for large organizations, reducing support tickets by 30%, and improving enterprise adoption by 25%
● Co-led end-to-end implementation of Exploit Prediction Scoring System (EPSS) across advisory database and Dependabot alerts rules engine, enabling 250,000+ CVEs to be prioritized by exploitation probability via REST API, GraphQL, Elasticsearch, and UI — leading to successful GA launch

### Principal Software Engineer @ Code for America
Jan 2023 – Jan 2024 | San Francisco Bay Area
● Enhancing a free-to-low-income-Americans tax filing tool using Ruby on Rails to help find optimal tax deductions, subsidized by the US government, and assisted 203,000+ tax filers in fiscal years 2021-2022
● Led the development of an online tool aiding 20K+ low-income senior American citizens, securing $3M+ in tax refunds. 
● Orchestrated initiatives to enhance process efficiency and architectural robustness, driving sustainable improvements across the platform.
● Pair program/collaboration to onboard new engineers and spread knowledge among team members
● Testing of application logic using RSpec

### Senior Software Engineer @ Inbox Health
Jan 2023 – Jan 2023 | Connecticut, United States
Practice Management integration engineering
● Built a monthly reporting tool to give executive leadership insights into volume integration that consumed endpoint info from AWS S3 and alerted Slack channels.
● Gave company-wide demos for testing integration communication
● Fixed mission-critical bugs in Practice Management system integrations that helped the company to unblock revenue.
● Performed detailed analysis for integrations that allowed to determine whether new integration code had desired effects in a demo environment and did not introduce regressions prior to deploying to production.
● Delivered a mechanism for generating a patient list that was to be sent to collections in an automated fashion.

### Senior Software Engineer @ Teladoc Health
Jan 2021 – Jan 2023 | Purchase, New York, United States
Onshore team leader, responsible for team releases:
● Successfully delivered 20+ full-stack features on our main product powered by Ruby on Rails and GraphQL in the backend, and React.js in the front end.
● Led architecture improvements that improved loan application requests by splitting the asynchronous jobs into batches by 30% and prevented failures and removed reprocessing.
● Designed and developed a service to deliver data-driven signals from external API using KeyCloak OAuth, Rails, React.js, GraphQL, and client-side state management (Redux, Hooks).
● Responsible for managing releases and deploys for our VPCC (Clinical Team), acting as a representative for onshore and offshore portions of the team. Monitored deploys using SumoLogic.
● Delivered major EHR migration on time and on budget, including the refactoring of API calls, and React UI components, which improved the flow for thousands of nurses company-wide.
● Modified flow using backend Rails engines and client-side component updates.
● Delivered over 3 proofs of concepts and presented the different findings in engineering-wide sessions.
● Ensuring we deliver on our agreed SLA by providing production-level support in the on-call rotation.
● Acting as a technical consultant for our product team and non-technical stakeholders, offering insights into the
capabilities of our tech stack, as well as refining requirements and estimations.
● Troubleshooting production incidents using Cloud logging tools like SumoLogic and DB production replicas.
● Contributed as part of a cross-functional Agile team of 6+ developers, and dedicated QA’s.
● Mentored and ensured best practices through code reviews and pair programming with junior engineers.
Technologies: Ruby on Rails, JavaScript, TypeScript, Node.js, GraphQL, RSpec, Redux, React.js, React Hooks, Jenkins, MySQL, Git, SumoLogic, Restful APIs, Architecture, Tech Talks, Engineering Presentations.

### Software Engineer @ MotoRefi
Jan 2019 – Jan 2021 | Arlington
Built several productivity-boosting processes by removing manual labor using software solutions and revolutionized tier 3 support processes by removing engineers almost entirely from the process.
● Technical lead on SRE effort that revolutionized on-call rotation by removing all possible engineer touchpoints.  Standardized support documentation, made automated script fixes into CRM application, and hired a Tier 3 manager to use tools built by engineers.  Engineers could now focus on root-cause issues to unblock revenue-producing leads.  Scaled lead volume from 100 to over 3k leads per month while only one engineer was kept on the PagerDuty rotation. 
● Built React.js component library for the company website
● Improved the CRM application performance by improving slow queries.  Used EXPLAIN results to determine whether queries could benefit from adding DB index and improved ORM-produced queries.  Reduced Heroku Dyno timeouts (H12) by 22%
● Google Calendar client integration into internal CRM which added the ability to get reminders, and CRUD events, improving sales floor productivity and eliminating context switching.
● Worked closely with designers to build new website features and career pages.
● Integrated internal CRM with Mailchimp to manage user tags for marketing campaign automation.
● Integrated with EasyPost gem for shipping labels with USPS and FedEx.
● Ensured best practices in Backend through code reviews.
Technologies: Ruby on Rails, JavaScript, Sorbet, React.js, TypeScript, GraphQL, Hasura, PostgreSQL, SQL Analyzer, Docker, NewRelic, Rollbar, MailChimp, SRE, DB Optimization, Application Design, Technical lead, Heroku, PagerDuty, CircleCI.

### Software Developer @ General Dynamics Information Technology
Jan 2017 – Jan 2018 | Rockville, Maryland, United States
Wrote internal software tools to support anti-terrorism initiatives.
● Developed Rails and Redis internal API to serve content to heavily visited websites and tested load performances using JMeter.
● Wrote internal API daily syncing tools to serve data to large public websites using Ruby on Rails and React.js
● Transformed resource-intensive synchronous operations into Sidekiq jobs
● Transformed RESTful operations into Event sourcing using AWS SQS queues
● Setup Apache VHosts for production web applications
● Deployed Rails apps using Capistrano
Technologies: Ruby on Rails, React.js, MySQL, Redis, Capistrano, AWS (S3, SQS), Apache (VHost, JMeter), Sidekiq

### Web Developer @ GeneDx
Jan 2015 – Jan 2017 | Gaithersburg, Maryland, United States
Responsible for writing software to support BioInformatics applications for genetic laboratory treatment.
● Developed an internal system for managing newly hired employees using Rails 4.2 and PostgreSQL database. This automated much of the new hire process and connected hand-off between each department when onboarding new staff. Reduced manual intervention for each new employee by 70%
● Improved performance in search functionality in exome application written in PHP.  Moved processing to server-side with added DB queries and pagination via Ajax.  Prevented page time-outs making the page snappy.
● Optimized queries by using eager loading to remove n+1 and improve application performance.
Technologies: Ruby on Rails, PostgreSQL, Query Optimization, Ajax, PHP, JavaScript, HTML, CSS, BitBucket, jQuery, RESTful APIs, jQplot, DevOps (ElasticSearch)

### Developer @ CTC Inc
Jan 2012 – Jan 2015 | Washington DC-Baltimore Area
Responsible for software tools and technologies to support search operations for the Department of State:
● Intake XSLT processors from Google Search Appliance crawled content and combined it to build the same look-and-feel search pages for 200+ World embassies and consulates.  Used JS and CSS for responsive design.
● Automated scripts to obtain a dynamic list of websites and process search pages using Ruby, Python, and Bash.
● Troubleshoot JavaScript library bugs
Technologies: XSLT processors, Responsive design, Ruby, Python, Bash, AngularJS, MySQL, JavaScript, HTML, CSS, Git, jQuery, Google Search Appliance, SOAP & RESTful APIs, SalesForce, DevOps (Apache certificate install, phpLDAPadmin, vagrant, VirtualBox)


## Education
### Bachelor of Science - BS in Computer Engineering
University of Maryland - A. James Clark School of Engineering
Jan 2010 – Jan 2012

### Associate of Arts (A.A.) in Computer Science
Montgomery College
Jan 2007 – Jan 2009

### Associate of Arts (A.A.) in Management Information Systems, General
Montgomery College
Jan 2007 – Jan 2009


## Contact & Social
- LinkedIn: https://linkedin.com/in/ricardo-kreyhsig

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Source: https://flows.cv/ricardokreyhsig
JSON Resume: https://flows.cv/ricardokreyhsig/resume.json
Last updated: 2026-03-22