Available for remote contract / part-time work

Thiago H. R. Costa

Thiago H. R. Costa

Software Engineer | Ruby on Rails & React | Backend-Focused | Full-Stack

Brazil (Remote)

Building and scaling mission-critical backend systems with Ruby on Rails, from EdTech to industrial-scale data pipelines.

GitHub LinkedIn Email
01

About

I'm a backend-focused software engineer with 5+ years of experience building and evolving software across EdTech, FinTech, and industrial sectors. I specialize in Ruby on Rails and React, designing systems that stay reliable under real-world scale, from high-frequency data pipelines to compliance-critical platforms (GDPR, LGPD, CCPA). My work spans distributed backend architecture, API integrations, background processing, and product development.

Over the last two and a half years, I've partnered with US companies and international engineering teams, taking ownership of the complete lifecycle, from understanding business requirements to implementation, deployment, and production support.

I enjoy working where product thinking meets engineering. Whether collaborating with stakeholders to define new features, architecting backend services, or improving existing platforms, my goal is software that solves meaningful problems, scales with the business, and creates measurable impact.

02

Case Studies

Case 01

Vekto Engenharia

Real-Time Seismographic & Climate Monitoring

Real-time seismographic and climate monitoring for one of Brazil's largest mining operators, covering thousands of active sites.

40s → 3sprocessing latency across 4,000+ sites
83% → 23%Heroku worker load
99.9%production uptime
Problem
Data was arriving too slowly to act on. The ingestion pipeline was a single monolith, and the Heroku workers powering it were buckling under the load of thousands of active mining sites reporting in real time.
Solution
Refactored the monolith into focused microservices, rebuilt the ingestion pipeline around Sidekiq and Redis, and introduced a validation layer built to withstand audits from environmental regulators. Mentored a team of 4 junior engineers through the migration.
Result
Processing latency dropped from 40 seconds to 3 seconds across more than 4,000 active mining sites, worker load on Heroku fell from 83% to 23%, and the system has held 99.9% uptime in production ever since.
Ruby on RailsSidekiqRedisPostgreSQLNokogiriSeleniumJWTMicroservicesReactHeroku

Case 02

Idelsoft / Hubble Contacts

US E-Commerce, Compliance & Accessibility

A US e-commerce platform selling contact lenses and glasses, operating under strict privacy and accessibility requirements.

Problem
The storefront needed to meet GDPR and CCPA privacy requirements and ADA/WCAG accessibility standards, without slowing down a high-traffic checkout experience.
Solution
Built automated DSAR (data access and deletion) systems to handle privacy requests at scale, reworked cart and product navigation for keyboard and reduced-mobility accessibility, and shipped high-throughput Rails APIs backed by Sidekiq and Redis, working end-to-end inside a fully English-speaking agile squad.
Result
Shipped a compliant, accessible storefront without compromising throughput, with ownership spanning architecture through production support.
  • Automated DSAR pipeline for GDPR & CCPA requests
  • ADA/WCAG-accessible cart and navigation
  • High-throughput Rails APIs on Sidekiq + Redis
Ruby on RailsReactGatsbySidekiqRedisPostgreSQLREST APIs

Case 03

Sirius Education

LTI Integration, SSO & Certificate Automation

One of Latin America's top 100 EdTechs, looking to cut licensing costs and deepen its LMS integrations.

100%certificate data sync accuracy
Problem
The company was paying for third-party contract management software that didn't integrate deeply enough with its learning platforms.
Solution
Built an in-house contract management system to replace the licensed platform, integrated LTI (Learning Tools Interoperability) for LMS connectivity, researched and architected SSO with Coursera via OAuth2/OIDC, and automated certificate issuance end-to-end.
Result
Replaced a licensed third-party platform with in-house tooling and brought certificate issuance to 100% data sync accuracy.
  • In-house contract management system, replacing licensed software
  • LTI integration for LMS connectivity
  • SSO architecture research with Coursera (OAuth2/OIDC)
Ruby on RailsREST APIsPostgreSQLSidekiqRedisHerokuAWS
03

Projects Showcase

My Bookshelf

Product-oriented monorepo: API, web, mobile & recommendation service

A full reading platform built across every surface at once: a Rails API, a Next.js web app, and a dedicated FastAPI recommendation service, orchestrated together with Docker Compose, plus an Expo/React Native mobile client consuming the same API. JWT auth, OpenAPI-documented contracts, and an RSpec/Brakeman/RuboCop quality baseline back the whole stack.

Ruby on RailsNext.jsReact Native (Expo)FastAPIPostgreSQLRedisDockerRSpec
View on GitHub

Iron Cars Shop

AI-powered vehicle marketplace with lead matching & negotiation CRM

A vehicle marketplace that automates the slowest parts of buying and selling a car: a conversational chatbot qualifies leads on the landing page, an AI matching engine pairs them against live inventory, and a built-in negotiation CRM with a Kanban pipeline carries the deal from first contact to close. Seller analytics sit behind three Stripe subscription tiers, backed by eager-loaded queries to keep dashboards fast under load.

Ruby on RailsPostgreSQLStripeStimulus.jsAI ChatbotCRM
Read the Engineering Notes

Kinko

Ledger-driven fintech platform with double-entry accounting

A digital-bank simulation modeled the way real financial systems work: double-entry bookkeeping with immutable ledger entries, where balances are derived mathematically instead of stored as mutable state. Stripe handles external payment processing while Kinko's own Rails engine owns contract-based billing and financial domain logic, exposed via a secure REST API to a React Native mobile client.

Ruby on RailsReact NativePostgreSQLStripeDDDREST APIs
Read the Engineering Notes
04

Tech Stack

Backend

RubyRuby on RailsSidekiqRedisPostgreSQLREST APIsJWT

Frontend

ReactReact NativeGatsbyTypeScriptHTMLCSS

Data / Automation

NokogiriSeleniumETL Pipelines

DevOps / Infra

HerokuAWSCI/CDGit workflowsMicroservices

Compliance

GDPRCCPALGPDWCAG / ADA Accessibility

Testing

RSpec
05

Experience

  1. Sirius Education

    Dec 2025 – Present

    Software Engineer (Part-time / Contract)

    One of the top 100 EdTechs in Latin America, focused on educational services and student lifecycle management.

    • Designed internal APIs automating the full student lifecycle: registration, digital signatures, and contract issuance.
    • Built synchronization workflows for student records and grades across multiple platforms, keeping data consistent under unified access control.
    • Built custom webhooks automating enrollment and certificate workflows for partner units.
    • Own the full deployment lifecycle: database migrations, backup integrity, and production releases.
    Ruby on RailsREST APIsPostgreSQLSidekiqRedisHerokuAWSHoneybadger

  2. Vekto Engenharia

    Sep 2023 – Present

    Software Engineer (Part-time / Contract)

    Engineering company behind a real-time seismographic and climate monitoring system for one of the largest mining companies in Brazil.

    Concurrent part-time engagement alongside full-time work

    • Built a background system correlating seismic readings with scheduled blast plans, auto-flagging anomalies and escalating them to geological safety teams.
    • Engineered a 24/7 external data pipeline with Nokogiri and Selenium, transforming raw feeds into structured, JWT-authenticated API calls.
    • Configured CI/CD pipelines and Git workflow standards (branch protection, commit/push rules) for consistent deployments across the team.
    • Own the full production release cycle (merges, deployments, migrations, and backup integrity), with rollback procedures for mission-critical infrastructure.
    Ruby on RailsSidekiqRedisPostgreSQLNokogiriSeleniumJWTMicroservicesReactHeroku

  3. Idelsoft (Client: Hubble Contacts)

    Sep 2023 – Dec 2025

    Software Engineer (Full-time)

    Software development consultancy providing engineering services to Hubble Contacts, a US-based e-commerce company specializing in contact lenses and glasses.

    • Optimized React and Gatsby frontends for performance and accessibility, cutting page load times and tightening frontend-backend integration.
    • Orchestrated third-party Payments and Privacy API integrations, automating critical business flows while keeping data consistent across the platform.
    • Made shopping cart, product carousels, and site navigation fully keyboard-accessible, covering adding, removing, and browsing products, so users with reduced mobility could shop entirely without a mouse.
    • Operated as a key contributor in an English-speaking Agile squad, owning features end-to-end from architecture to production monitoring.
    Ruby on RailsReactGatsbySidekiqRedisPostgreSQLREST APIs

  4. PWC Solutions

    Jul 2023 – Dec 2023

    Software Engineer Consultant (Part-time, ~2h/week)

    Brought in as a consultant to clear a backlog of test coverage gaps, security vulnerabilities, and LGPD compliance work.

    • Neutralized SQL Injection and CRLF Injection vulnerabilities through secure query patterns and strict input sanitization.
    • Introduced RSpec testing practices from near-zero, reaching 90%+ coverage and cutting regression bugs.
    • Implemented LGPD (Brazil's GDPR) compliance adaptations built on privacy-by-design principles.
    • Elevated team standards through rigorous code reviews, pair programming, and mentorship of junior developers.
    Ruby on RailsRSpecPostgreSQLCI/CDLGPD

  5. Novamente Software House

    Jul 2021 – Sep 2023

    Software Engineer (Part-time / Contract)

    Software house where I contributed to multiple client projects, including the real-time monitoring platform that later became Vekto Engenharia's core product.

    Concurrent part-time engagement alongside the full-time role at Mercatório

    • Led end-to-end development of a 24/7 real-time mining monitoring platform, owning the SDLC from requirements through database and service design.
    • Built Nokogiri/Selenium parsing pipelines to automate ingestion of geological and climate reports into a centralized, queryable database.
    • Designed and maintained REST APIs for secure data exchange with third-party environmental systems, ensuring data integrity and low-latency communication.
    • Re-architected synchronous bottlenecks into async workflows with Redis and Sidekiq, resolving recurring outages and reaching 99.9% uptime.
    Ruby on RailsReactReact NativeTypeScriptRedisSidekiqPostgreSQLNokogiriSelenium

  6. Mercatório – Soluções para Precatórios LTDA

    Aug 2021 – Jul 2022

    Software Developer (Full-time)

    Fintech/LawTech startup building data and investment platforms for Brazilian court-ordered debt, running 24/7 scrapers across court systems.

    • Managed high-scale scrapers running 24/7 across Brazilian court systems, holding zero data loss and 99% uptime.
    • Owned ETL pipelines turning large legal datasets into clean feeds for the core Data and Investment APIs.
    • Contributed across a three-platform architecture: Data Collector, Data Sales API, and Investment Platform.
    • Reduced scraper downtime through comprehensive RSpec unit tests and advanced debugging workflows for asynchronous background tasks.
    RubyRuby on RailsReactRSpecPostgreSQLREST APIsETL PipelinesNokogiriSelenium
06

Education & Languages

  • Postgraduate Degree in Artificial Intelligence, with Emphasis in Machine Learning

    XP Educação · 2024

  • Full-Stack Web Development Bootcamp (360h)

    Le Wagon, São Paulo · 2021

  • MBA in Big Data & Competitive Intelligence

    Unimérica · 2021

  • Associate Degree in Systems Analysis & Development

    Estácio · 2019

  • Bachelor of Laws

    PUC MINAS · 2009

  • EnglishC2 Proficient (EF SET 76/100)
  • PortugueseNative

About Me

07

Outside Code

When I'm not writing Ruby or debugging production issues, I'm usually on the BJJ mats (currently blue belt). It's the closest thing to engineering I know: you get thrown off, figure out what went wrong, and try again until it works.

I'm also a reader. Currently working through Moby Dick, and I just finished The Shining.

Let's work together

Open to remote Ruby on Rails opportunities: contract, part-time, or full-time.

thiagohrcosta86@gmail.com
github.com/thiagohrcosta linkedin.com/in/thiagocosta-3566a4176