Luis Antonio Arreola Gutiérrez

Bus ticketing platform. Hired as a Rails developer, I worked on three teams with different stacks according to business needs.

Elixir/Phoenix Team (first ~6 months)

• Personalization: Personalized booking experience based on customer behavior data from Mixpanel: pre-filled passenger data, seat pre-selection and targeted promotions

Python/Django Team (~3 months · pricing, inventory and routes)

• ML Sales Forecasting: Trained several prediction models (e.g. Random Forest) on historical sales data and visualized the forecast to support business decisions
• Data Extraction with dbt: dbt models to extract only the data needed for analysis and forecasting, without interfering with daily operations

SaaS Team (Ruby on Rails, until my departure)

• SaaS Admin Panel: Centralized management of multiple clients (hotels and providers) with accounts, settings and permissions
• Purchase Platform: Development and maintenance of the core transaction system: checkout flow, tickets and bank transfers
• Payment Gateways: Contributed to the PayPal, Adyen, Mercado Pago, Aplazo and Costapass integrations for operations in several Latin American countries
• WordPress Migration: Migrated the content site from Rails to WordPress, with template-driven dynamic pages and automatic updates via API
• Transactional Emails: Newsletters, confirmations and notifications with MJML
• E2E Testing: Automated Playwright tests for critical checkout and payment flows

Cross-team

• AI Tooling & AI-Assisted Development: Built skills for AI agents (Claude Code, Cursor, Codex) and OpenSpec documentation, shared across projects of the different teams
• Multi-stack Work: Handled projects in different languages and platforms simultaneously, highlighted in my performance reviews
• Mentoring: Mentored and coordinated 2–3 developers

Ruby on Rails Python/Django Elixir/Phoenix WordPress React/TypeScript PostgreSQL dbt Mixpanel PayPal/Adyen Playwright Docker Git

Logistics SaaS platform integrating multiple carriers (Estafeta, DHL, FedEx, Redpack, PaquetExpress, among others) in a single platform.

• High-Performance Cached Reports: Implemented a caching system for shipment reports that cut load times from minutes to seconds for users with thousands of daily shipments
• International Zone Rates: Designed and implemented zone- and carrier-based pricing, giving more commercial flexibility across 5+ carriers
• Multi-Carrier Integration: Set up, maintained and integrated Estafeta, DHL, FedEx, Redpack and PaquetExpress APIs, among others, with per-account and per-zone credentials, adding new carriers as the platform grew
• Flutter Desktop App: Shipping label generation with direct printing to A4 or thermal printers
• React Frontend: Upgraded the application frontend to React
• Async Processing with Resque: Moved heavy tasks (bulk imports, report generation, SAP sync) to background jobs, improving system response times
• SAP Enterprise Integration: Built automatic sync of payments, invoicing and account statements with the company's SAP system
• OpenPay Payments: Integrated payment processing, billing reports and transaction reconciliation with OpenPay
• Docker Infrastructure: Standardized development environment with Docker Compose, including PostgreSQL, Redis and Resque workers

Ruby 2.4 / 3.0 Rails PostgreSQL Redis Docker AWS React Flutter Swagger Resque OpenPay GitFlow

Web application development for the hotel industry, ensuring great display and performance on every device.

• Frontend: Responsive Bootstrap sites (desktop, tablet, mobile) with corporate designs
• Backend: Rails and MySQL, with an admin panel for dynamic content and resource editing
• Infrastructure: NGINX + Passenger, AWS
• Communication: Push notifications with ActionCable
• Integrations: Internal Python libraries for API consumption
• Users: Sign-up via email, phone and social networks
• Marketing: Mass email marketing and automated promotions calendar
• Jobs: Scrapers for pricing provider APIs
• SEO: Simplified SEO configuration
• Mentoring: Mentored and coordinated one developer

Ruby Rails MySQL Bootstrap ActionCable AWS NGINX Python

Classified ads platform for buying and selling products and services, with store, offer and digital magazine management.

• Advanced Search System: Built a search engine with category, super-category and location filters plus AJAX autocomplete, improving discovery for thousands of users
• Mobile App API: REST endpoints for user sign-up/login, offer sync, store management and Base64 image upload for the Android app
• Image Management and Upload: Batch image processing with CarrierWave, AWS S3 and CloudFront, including automatic resizing, ImageMagick optimization and a Refile-to-CarrierWave migration
• SEO and Performance: Automatic sitemap, canonical URLs, optimized meta tags, image lazy loading and FriendlyId for friendly URLs
• Landing Pages and Frontend: Designed and built responsive landing pages with interactive sliders, optimized pagination and a mobile-first experience for tablets and smartphones
• Backend Admin: Full admin panel for stores, offers, categories, digital magazines and users with role and permission control
• ElasticSearch Migration: Migrated the search engine from Sunspot (Solr) to ElasticSearch
• Background Jobs: Background processing with Sidekiq for image generation, push notifications and heavy tasks
• Mentoring: Mentored and coordinated a team of 3–5 people (developers and designers)

Ruby Rails MySQL Redis MercadoLibre PayPal Sunspot ElasticSearch