Hi, I'm Colleen Seletos, a Senior Software Engineer with over 8 years of experience designing and developing complex web-based applications. I specialize in cutting-edge technologies like JavaScript and Ruby on Rails, with a passion for building scalable, resilient systems that drive business growth. Throughout my career, I've enjoyed optimizing backend processes and integrating microservices architectures to enhance performance and reduce costs. I believe in writing clean, efficient code and constantly improving system reliability while keeping user needs at the forefront. Outside of work, I’m always excited to learn new technologies and contribute to innovative projects that make a real impact.

Colleen Seletos

Hi, I'm Colleen Seletos, a Senior Software Engineer with over 8 years of experience designing and developing complex web-based applications. I specialize in cutting-edge technologies like JavaScript and Ruby on Rails, with a passion for building scalable, resilient systems that drive business growth. Throughout my career, I've enjoyed optimizing backend processes and integrating microservices architectures to enhance performance and reduce costs. I believe in writing clean, efficient code and constantly improving system reliability while keeping user needs at the forefront. Outside of work, I’m always excited to learn new technologies and contribute to innovative projects that make a real impact.

Available to hire

Hi, I’m Colleen Seletos, a Senior Software Engineer with over 8 years of experience designing and developing complex web-based applications. I specialize in cutting-edge technologies like JavaScript and Ruby on Rails, with a passion for building scalable, resilient systems that drive business growth. Throughout my career, I’ve enjoyed optimizing backend processes and integrating microservices architectures to enhance performance and reduce costs.

I believe in writing clean, efficient code and constantly improving system reliability while keeping user needs at the forefront. Outside of work, I’m always excited to learn new technologies and contribute to innovative projects that make a real impact.

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Experience Level

Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
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Language

English
Fluent

Work Experience

Senior Software Engineer at Ethena
January 1, 2020 - May 1, 2024
Implemented microservice architecture using Ruby on Rails, MySQL/PostgreSQL, and Elasticsearch for 15 platforms, managing 1.5M users per hour. Optimized processing efficiency by 30% and minimized system errors by 20% through backend optimizations. Integrated Sidekiq, processing 1,000+ background jobs daily, increasing system efficiency and reducing server load by 25%. Built a custom data retrieval layer using Ruby on Rails’ Active Record, improving data access speed and increasing processing efficiency by 50% for real-time analytics. Deployed RESTful APIs with AWS Lambda, reducing server costs by 20% and boosting frontend-backend integration by 30%.
Full Stack Engineer at Salsify
May 1, 2017 - September 1, 2019
Oversaw 45k+ orders for Shopify applications using React and Ruby on Rails, optimizing system scalability and performance. Boosted user satisfaction by 25% and reduced bounce rates by 15% through consistent UI development with Shopify Polaris. Replicated app features on the website in 15 days, boosting accessibility and engagement, and increasing orders by 23%. Constructed scalable microservices with Ruby on Rails, achieving a 40% increase in scalability and a 25% reduction in downtime. Minimized costs by $100K annually through PostgreSQL optimization and horizontal scaling. Increased deployment speed by 30% using Heroku, cutting operational costs by 20%.
Full Stack Developer at Salsify
August 1, 2016 - May 1, 2017
Crafted an e-commerce platform, boosting user efficiency by 25% and minimizing deployment time by 40%. Leveraged React and PostgreSQL in various projects to enhance UI/UX, resulting in a 40% increase in user engagement and streamlined database management. Engineered scalable server-side applications using Ruby on Rails, improving data handling by 35% and supporting a 50% increase in e-commerce transactions. Streamlined applications with Stimulus, reducing JavaScript usage by 40% and improving performance by 30%. Employed RSpec for testing, achieving a 99% bug-free codebase and enhancing system reliability by 25%. Customized Shopify for e-commerce, increasing inventory management efficiency by 30% and reducing checkout time by 20%.
Full Stack Developer at AKASA
October 1, 2014 - June 1, 2016
Played a key role in developing React and Ruby on Rails applications, growing the user base by 35%. Improved data transfer efficiency by 40% using JSON and boosted application performance. Built server-side applications with Ruby, boosting performance by 35%, scalability by 40%, and reliability by 30%. Optimized frequently used APIs, achieving a 10x improvement in response times using New Relic for performance measurement.

Education

Bachelor's Degree at The University of Hong Kong
April 1, 2010 - October 1, 2014

Qualifications

Add your qualifications or awards here.

Industry Experience

Software & Internet, Retail, Professional Services

Experience Level

Expert
Expert
Expert
Expert
Expert
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
Intermediate
See more