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I’m a Ruby on Rails engineer focused on building reliable Rails APIs, data integrity solutions, and SaaS products that solve real problems for real users. My background started in QA, where I built an end-to-end testing mindset with tools like Cypress and Cucumber, and that discipline carries through to how I design systems, write tests, and handle production incidents today. Over my career, I’ve worked across backend architecture, PostgreSQL, Redis, Sidekiq, GraphQL, and React/TypeScript frontends—often taking full ownership of critical workflows. From creating real-time executive dashboards using CQRS patterns to migrating legacy services into PostgreSQL-backed microservices and empowering support teams with self-serve conflict resolution, I enjoy turning messy, high-impact operational needs into dependable software.…I’m a Ruby on Rails engineer focused on building reliable Rails APIs, data integrity solutions, and SaaS products that solve real problems for real users. My background started in QA, where I built an end-to-end testing mindset with tools like Cypress and Cucumber, and that discipline carries through to how I design systems, write tests, and handle production incidents today. Over my career, I’ve worked across backend architecture, PostgreSQL, Redis, Sidekiq, GraphQL, and React/TypeScript frontends—often taking full ownership of critical workflows. From creating real-time executive dashboards using CQRS patterns to migrating legacy services into PostgreSQL-backed microservices and empowering support teams with self-serve conflict resolution, I enjoy turning messy, high-impact operational needs into dependable software.

Alexandre Domingos Filho

Software Engineer, Back-End Developer, Programmer, +2

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I’m a Ruby on Rails engineer focused on building reliable Rails APIs, data integrity solutions, and SaaS products that solve real problems for real users. My background started in QA, where I built an end-to-end testing mindset with tools like Cypress and Cucumber, and that discipline carries through to how I design systems, write tests, and handle production incidents today. Over my career, I’ve worked across backend architecture, PostgreSQL, Redis, Sidekiq, GraphQL, and React/TypeScript frontends—often taking full ownership of critical workflows. From creating real-time executive dashboards using CQRS patterns to migrating legacy services into PostgreSQL-backed microservices and empowering support teams with self-serve conflict resolution, I enjoy turning messy, high-impact operational needs into dependable software.…I’m a Ruby on Rails engineer focused on building reliable Rails APIs, data integrity solutions, and SaaS products that solve real problems for real users. My background started in QA, where I built an end-to-end testing mindset with tools like Cypress and Cucumber, and that discipline carries through to how I design systems, write tests, and handle production incidents today. Over my career, I’ve worked across backend architecture, PostgreSQL, Redis, Sidekiq, GraphQL, and React/TypeScript frontends—often taking full ownership of critical workflows. From creating real-time executive dashboards using CQRS patterns to migrating legacy services into PostgreSQL-backed microservices and empowering support teams with self-serve conflict resolution, I enjoy turning messy, high-impact operational needs into dependable software.

Available to hire

I’m a Ruby on Rails engineer focused on building reliable Rails APIs, data integrity solutions, and SaaS products that solve real problems for real users. My background started in QA, where I built an end-to-end testing mindset with tools like Cypress and Cucumber, and that discipline carries through to how I design systems, write tests, and handle production incidents today.

Over my career, I’ve worked across backend architecture, PostgreSQL, Redis, Sidekiq, GraphQL, and React/TypeScript frontends—often taking full ownership of critical workflows. From creating real-time executive dashboards using CQRS patterns to migrating legacy services into PostgreSQL-backed microservices and empowering support teams with self-serve conflict resolution, I enjoy turning messy, high-impact operational needs into dependable software.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Language

English

Intermediate

Spanish; Castilian

Beginner

Work Experience

Ruby on Rails Engineer (Mid-level) at Kria Investments

November 1, 2025 - Present

Built and shipped a real-time executive KPI dashboard using a CQRS approach with Rails, PostgreSQL, Sidekiq, and Redis. Designed scheduled read-model updates every 5 minutes for reliability and enabled leadership to replace a manual weekly reporting process with live metrics used in client acquisition and investor presentations. Covered investment volume, active/new investors, recurring investor metrics, average ticket by offer type and entity, cancellations, offer health tracking, capture progress vs goals, and geographic distribution. Also contributed to evaluating the dashboard as a potential white-label revenue opportunity.

Ruby on Rails Engineer (Mid-level) at VR

April 1, 2024 - Present

Owned a critical data integrity solution after a forced migration that affected ~30,000 users locked out. Designed system architecture that integrated with internal APIs to compare user data, identify inconsistencies, select the correct source of truth, and safely synchronize records. Built a React + TypeScript + Tailwind UI for N2 Support to search by name/CPF/CNPJ/email, view cross-system status instantly, and resolve conflicts with a single click. Reduced resolution time from 4–5 minutes of manual Postman work to under 30 seconds per user and developed/maintained Rails APIs for business-critical benefits platform flows (login, access, consistency).

Ruby on Rails Engineer at Encora Inc

November 1, 2022 - April 1, 2024

Implemented GraphQL migration for a complex customer onboarding service, extracting it from a legacy Rails/MySQL monolith into a PostgreSQL-backed microservice within a cross-functional team. Interpreted and remodeled legacy data structures into a normalized GraphQL schema while preserving validations, business rules, and data contracts. Built a high-complexity onboarding flow (company registration, employee/dependent enrollment, document/date validations) and integrated with insurance and benefits providers. Added automated RSpec tests to ensure migrated behavior matched the legacy system before cutover.

Ruby on Rails Jr Developer at Sparck Co.

October 1, 2021 - October 1, 2022

Created Service Objects for critical business logic, including a permissions provisioning flow that automatically granted correct access levels for a separately contracted paid extension. Fixed a production payment failure caused by incorrect Stripe payload after changes to a payment class, restoring checkout stability and preventing further transaction errors. Built PostgreSQL materialized views powering client-facing analytics dashboards for recognition metrics and gift card transactions (sender/recipient/value/spend tracking). Wrote and corrected unit tests to improve code reliability.

QA Engineer at Sparck Co.

January 1, 2021 - October 1, 2021

Built automated testing infrastructure from scratch, including Cypress setup and Cucumber/Gherkin integration, replacing a fully manual QA process. Mapped and implemented 1,200+ end-to-end scenarios covering happy paths and edge cases across a highly configurable platform with wide client customization. Reduced the volume of production bugs by providing consistent regression coverage before releases.

Senior IT Analyst at UPS Supply Chain Solutions

August 1, 2016 - September 1, 2021

Managed IT infrastructure aligned with business needs across internal departments and external clients, supporting logistics operations in Brazil and Costa Rica. Led infrastructure projects for new client onboarding including systems and telecom setup and oversaw documentation and infrastructure audits. Managed server documentation, compliance-oriented audits, and coordinated home-office equipment rollout during the pandemic.