Senior fullstack engineer building scalable, reliable web platforms in Ruby on Rails and React.
18+ years across system architecture, API design, cloud-native AWS infrastructure, and the Site Reliability practices that keep high-traffic products healthy in production.
Track record of leading legacy-to-cloud modernizations, mentoring engineers, and shipping in distributed, multicultural US/Brazil teams.
- 18+ years building and operating scalable platforms in Ruby on Rails and React.
- Full lifecycle: system architecture, API design, and cloud-native infrastructure on AWS.
- Led legacy-to-cloud modernizations and the SRE practices that keep high-traffic products reliable.
EXPERIENCE
Transcenda
Total: 5 monthsFull-Stack Ruby EngineerFeb 2026 – Jun 2026 · 5 months
- Design backend services and APIs with an emphasis on system architecture, performance, and maintainability.
- Drive platform modernization work, improving reliability and reducing technical debt across the stack.
- Collaborate across distributed, multicultural teams to ship reliable, scalable features.
Disney & ESPN Media Networks
Total: 11 years 7 monthsSite Reliability EngineerJan 2021 – Feb 2026 · 5 years 2 months
- Authored infrastructure-as-code in Terraform to automate provisioning and standardize environments.
- Contributed Ruby on Rails code for application improvements and ongoing platform modernization.
- Led advanced troubleshooting, observability, and incident response to sustain high availability (~99.9% uptime) of mission-critical services.
- Implemented proactive reliability practices that improved service quality and operational excellence.
Tech Lead, Ruby on RailsJun 2016 – Dec 2020 · 4 years 7 months
- Led and coordinated Ruby on Rails projects, aligning engineering efforts between teams in the United States and Brazil.
- Oversaw development of Swift-based iOS mobile applications, ensuring high-quality delivery.
- Maintained AWS security protocols safeguarding API and web applications.
- Authored onboarding reference materials and best practices, integrating new teams into ongoing projects with minimal disruption.
- Ran Scrum for feature development and Kanban for maintenance/bug workflows to keep delivery predictable.
Senior Software Engineer (Fullstack)Aug 2014 – May 2016 · 1 year 10 months
- Led the migration of ESPN’s CMS — handling posts, video, images, audio, and blogs — from Java/JSP on-premise to a cloud-native architecture on AWS using Ruby on Rails.
- Integrated a microservices architecture for image processing, video transcoding, and streaming.
- Stack: AWS RDS (MS SQL Server), AWS OpsWorks & Elastic Beanstalk, AWS SQS, New Relic, CircleCI.
Insight Soluções em Sistemas
Total: 2 years 5 monthsFounder & Technology ConsultantMar 2012 – Jul 2014 · 2 years 5 months
- Built Mapping My Money, a personal budget management web app.
- Built Syiwe, a web app unifying multiple personal cloud accounts to list, manage, and import files across services.
Khronus Soluções
Total: 1 year 9 monthsTechnical LeadJun 2010 – Feb 2012 · 1 year 9 months
Delivered web and mobile solutions for company clients; first experience owning client relationships, product design, and project management.
Sync Sistemas
Total: 1 yearSoftware EngineerJul 2009 – Jun 2010 · 1 year
- Stack: Ruby on Rails, HTML/CSS/JavaScript (jQuery), Apache + Passenger, Linux, Git, PostgreSQL + PostGIS, Asterisk VoIP gateway, Adhearsion (Ruby VoIP).
Interjato ISP
Total: 1 year 9 monthsRuby DeveloperOct 2007 – Jun 2009 · 1 year 9 months
- Stack: Ruby on Rails, MySQL, HTML/CSS/JavaScript (jQuery), Apache + Passenger, Linux, Git.
Federal Institute of Rio Grande do Norte (IFRN)
Total: 8 monthsProgrammer (Intern)Mar 2007 – Oct 2007 · 8 months
Deployed and extended the Moodle e-learning platform (PHP) used to deliver remote classes to students.
PROJECTS
Mapping My Money (2012)
- Personal finance platform with social goal sharing.
- Built with Ruby on Rails and banking API integrations.
- Finalist in Buscapé’s national fintech challenge.
Syiwe (2013)
- Co-founded web/mobile platform connecting companies and users.
- Built Ruby on Rails backend and JavaScript frontend on AWS.
- Selected for FIESP’s Acelera Startup program.
Klipbox (2014)
- Automates tracking of 50k+ news sources.
- Scalable backend with Node.js and MongoDB; integrated AI analysis.
- Selected by Start-Up Brasil/SEED with investment; reduced monitoring time by 90%.
DocFlux (2015)
- Templating and batch PDF processing for scalable document generation.
- Node.js server, PDF.js rendering, MongoDB storage.
- Increased productivity by eliminating repetitive manual tasks.
PROFILE
I’m a senior fullstack software engineer with 18+ years building and operating scalable, reliable web platforms in Ruby on Rails and React. My experience spans the full lifecycle — system architecture, API design, cloud-native infrastructure on AWS, and the Site Reliability practices that keep high-traffic products healthy in production. I’ve led legacy-to-cloud modernizations, mentored engineers, and shipped in distributed, multicultural US/Brazil teams. Outside of work, I’m a lifelong learner and creative spirit who enjoys music and impersonation. Portuguese (native) · English (professional working) · Spanish (limited working).
SKILLS
| Skill Category | Skill Name | Proficiency Level | Years of Experience |
|---|---|---|---|
| Programming Languages | JavaScript | 95% | 18 |
| Programming Languages | Ruby | 95% | 18 |
| Programming Languages | Java | 95% | 18 |
| Programming Languages | Swift | 73% | 9 |
| Programming Languages | DotNet | 88% | 15 |
| Programming Languages | Python | 75% | 10 |
| Frameworks | Ruby on Rails | 75% | 10 |
| Frameworks | Sinatra | 65% | 6 |
| Frameworks | RESTful APIs | 80% | 12 |
| Cloud & DevOps | AWS | 70% | 8 |
| Cloud & DevOps | Docker | 68% | 7 |
| Cloud & DevOps | Kubernetes | 60% | 4 |
| Cloud & DevOps | CI/CD | 70% | 8 |
| Cloud & DevOps | Terraform | 60% | 4 |
| Data Platforms | PostgreSQL & PostGIS | 73% | 9 |
| Data Platforms | MySQL | 75% | 10 |
| Data Platforms | MongoDB | 65% | 6 |
| Data Platforms | Elasticsearch | 63% | 5 |
| Tools & Practices | Git | 80% | 12 |
| Tools & Practices | Monitoring | 70% | 8 |
| Tools & Practices | Site Reliability Engineering | 60% | 4 |
| Tools & Practices | Test-Driven Development | 75% | 10 |
| Tools & Practices | Agile/Scrum | 75% | 10 |
| Tools & Practices | Linux/Unix Servers | 95% | 18 |
CONTACT
Let’s build reliable, user-centric products together. Reach out via email, phone, or the form below.
- Email: wkelyson@gmail.com
- Phone: +55 (84) 99186-4912
- Location: Brazil/SP/RN - (GMT-3)Open to international opportunities