Production-Ready Rails
Experienced in mature Rails codebases, ecommerce upgrades, legacy refactoring, authorization flows, background jobs, and business-critical backend features.
Senior Ruby on Rails Developer • SaaS • APIs • PostgreSQL
Building scalable Rails applications with clean architecture and production reliability.
I'm Oscar Olivera, a Ruby on Rails developer with strong experience in SaaS platforms, ecommerce systems, multi-tenant architecture, PostgreSQL optimization, REST APIs, and secure backend design. I help teams ship maintainable software that solves real business problems.
About Me
I specialize in production Rails systems where performance, maintainability, and clean domain modeling matter. My background combines software development, database design, API architecture, and years of technical leadership.
Strong Data Thinking
Deep appreciation for relational data modeling, query optimization, indexing, safe migrations, and designing systems that evolve without breaking production flows.
Business + Engineering
I translate product needs into scalable solutions, collaborate well with technical and non-technical teams, and care about delivering useful software, not just writing code.
Core Skills
Technologies and practices I use to design, improve, and support modern Ruby on Rails applications.
What I Can Help With
The kinds of Rails and backend problems I'm most comfortable solving for startups, SaaS teams, and product companies.
Rails Backend Development
Feature ownership end-to-end, service objects, domain logic, secure authentication and authorization, business workflows, and maintainable MVC structure.
API Design & Integration
Clean RESTful APIs, JSON workflows, third-party integrations, BFF-style endpoints, and systems designed for real frontend consumption.
Data Modeling & SQL Performance
PostgreSQL and MySQL schema design, associations, constraints, indexes, safe migrations, and optimization of slow queries.
Legacy Refactoring & Upgrades
Improving mature codebases safely, upgrading Rails and ecommerce stacks, and evolving production systems without breaking business flows.
Selected Experience
Recent roles and projects that reflect my specialization in Ruby on Rails, SaaS architecture, and business-critical web systems.
Ruby on Rails Developer — Icalia Labs / Wholesome / Arches
Working on a Ruby on Rails product codebase in a professional augmentation environment, collaborating in English with a product-focused team.
Freelance Rails Developer — NUBBE.NET
Architected and built a multi-tenant sports academy SaaS platform with subdomain isolation, APIs, PostgreSQL schema design, role-based access control, caching, and CI/CD.
Ruby Developer — Preunic
Upgraded and maintained a Spree ecommerce application, improved backend compatibility, and worked on API services for React-based micro frontends.
Ruby Developer Contractor — Avenue Code
Worked on Ruby applications involving CSP improvements, integration-test-driven debugging, and production code quality using RSpec and GitHub Actions.
Fullstack / Rails Developer — Acid Labs and other teams
Contributed to ecommerce, API, and product systems across multiple companies, combining backend ownership with practical frontend integration.
Featured Projects
Work that demonstrates system design, feature ownership, technical depth, and production responsibility.
NUBBE.NET — Multi-Tenant Sports Academy SaaS
Owned end-to-endA Ruby on Rails SaaS platform designed for sports academies to manage players, matches, teams, seasons, and tournament workflows.
- Designed subdomain-based tenant isolation for secure data separation.
- Modeled complex PostgreSQL relationships across players, categories, teams, tournaments, and match data.
- Built REST APIs, role-based access, and backend flows for coaches, assistants, and admins.
- Implemented CI/CD, caching, and maintainable service-driven Rails architecture.
Spree Ecommerce Upgrades & Customization
Production systemsWorked on high-value ecommerce applications built on Spree and Ruby on Rails, modernizing code and supporting real business operations.
- Upgraded legacy Spree platforms and adapted custom business logic to newer versions.
- Improved API compatibility for decoupled frontends and React-based pages.
- Helped optimize maintainability, data consistency, and backend behavior under production constraints.
Rails Security, Testing & Reliability Work
Quality-focusedProduction-oriented work around CSP, automated testing, debugging, and code confidence in mature Rails applications.
- Worked with RSpec-driven workflows to validate changes and debug integration issues.
- Improved Content Security Policy implementations in real apps.
- Supported safer deployments through better test reliability and CI-oriented thinking.