Mexico City, Mexico · mariogillazaro@gmail.com
https://linkedin.com/in/mario-gil-lazaro
Full-stack software engineer with 8+ years shipping production React/TypeScript, PHP, and Node.js applications, plus mobile (Flutter) delivery. Strong focus on testing culture, code quality, and technical mentoring, with experience across fintech, e-commerce, and time-tracking domains.
Typescript (proficient), Javascript (proficient), PHP (intermediate), Python (intermediate)
React, Vue, Mithril, Jest, React Testing Library, Node.js, Express, Koa, Flutter, MySQL, PostgresQL, MongoDB, Docker, Grafana, Sentry, Fullstory, Github Actions, Jenkins, VPS admin, AWS, DataDog
TDD, CI/CD, Agile, Technical Mentoring, System Design, AI-assisted development, Design Systems, Clean Code, Open Communication, Version Control
Built a self-hosted time-tracking app to replace paid subscription tools, used daily to track personal project and interview-prep time
Full-stack build: NestJS/TypeORM/SQLite backend with Google OAuth, React/Vite frontend, Playwright e2e tests, Sentry error monitoring, containerized with Docker and deployed via nginx to a custom domain
First project built end-to-end with AI-assisted development (Claude Code), used to evaluate the workflow for production-quality code
Raised unit testing coverage by roughly 50% in my team's new frontend code
Owned the team's mobile branch end-to-end — aligning design, mobile engineering, and QA — shipping Flutter features on schedule and within quality thresholds
Built and maintained PHP API endpoints as part of daily backend development work
Reduced team-wide production bug count by an estimated 10% by establishing testing strategies and reviewing roughly 80% of the frontend team's pull requests
Imparted a testing strategies tech talk to the team
Executed a large-scale data migration using Spark and Airflow
Reduced total blocking time on a critical customer-facing page by 92% through targeted performance profiling
Reduced time-to-interactive on the same page by 72% via code splitting and architecture improvements
Modernized the legacy frontend codebase, introducing linting rules, a stateless functional component convention with hooks, and domain-organized Redux stores for simpler component-to-store connections
Designed and implemented the first unit testing suite for our application
Collaborated with a team spanning 3 time zones, maintaining reliable delivery cadence
Taught higher-order functions and browser Javascript chapters in a Javascript training course
Implemented a payment and loan React application for a Thai fintech
Reduced the application's runtime errors in the Redux stores and
connect adapters to 0%
Taught Redux and React hooks in the team's React training course and a technical talk
Served as a main point of contact for the frontend team within a multicultural, 6+ nationalities team
Maintained and developed the company's website, handling ongoing feature work and bug fixes
Graduated from the trainee program and was selected for the company's exchange program, transferring to the Ho Chi Minh City team
Delivered a search/filter frontend for a municipal government's database within a 1-month deadline, learning web development from scratch (Mithril, Mongoose, Node.js, Bulma CSS) to do so
Authored deployment documentation and walked teammates through manual installation, since only authorized staff could access the government's on-site systems
B. Eng. Computer Systems — 2017 Universidad de Guanajuato