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Portfolio

William Montiel

Senior Software Engineer

Software Engineer with 12+ years of experience engineering high-scale, real-time systems. My trajectory spans from co-building a mass email marketing SaaS from scratch in a 3-person team, to architecting cloud-native telemetry platforms and leading international engineering teams on-site in Vietnam. Specializing in logistics, GPS tracking, and full-stack mobile ecosystems, I bridge complex backend architectures with effortless user experiences. My focus is simple: taking complete technical ownership, setting architectural standards, and stripping away complexity to build software that scales.

Experience

Dec 2024 — Present
Software Developer Engineer III
Zonar Systems
  • Team Leadership & Global Collaboration Spearheaded the mobile development division, leading an international engineering team on-site in Vietnam (Ho Chi Minh City) to align cross-border product delivery, optimize codebase performance, and streamline development workflows.
  • Cloud Architecture Architected and scaled high-throughput microservices using AWS Lambda, DynamoDB, React, and MySQL, significantly reducing data latency for real-time fleet tracking.
  • Technical Evolution A promotion to Software Developer 3 (SD3) due to consistent technical ownership, architectural vision, and mentorship of mid and junior talent.
Mar 2021 — Dec 2024
Senior Software Engineer
TSO Mobile / GPS Trackit
  • Recruited Back Brought back by a former manager into an expanded role. With Platform Manager matured and handed off to another team, I helped kick off the company's next flagship product.
  • GPS Trackit Cloud Co-built GPS Trackit Cloud, the large-scale platform our customers use to run their fleets — real-time vehicle tracking on the map, live camera streaming, alerts, driver-behavior monitoring, fuel-consumption insights, and reporting.
  • Full-Stack at Scale Delivered across a broad stack: React on the front end, AWS Lambda and Node.js services, MySQL and MongoDB, with parts containerized in Docker.
Oct 2020 — Mar 2021
Senior Software Engineer
Fullstack Labs
  • Geospatial Tooling Designed and developed a high-precision roof measurement tool from scratch using Vanilla JavaScript and the Google Maps API for a major drainage infrastructure enterprise, automating immediate client cost estimations and quoting.
  • E-commerce Migration Executed codebase refactoring and migration strategies for high-traffic platforms like Fulton Fish Market (NYC), transitioning legacy PHP architectures into optimized, modern systems.
Sep 2018 — Oct 2020
JavaScript Developer
TSO Mobile / GPS Trackit
  • Front-End Engineering Developed front-end features for the company's real-time GPS and geolocation platform using Ember.js.
  • Legacy Systems Moved into a legacy area of the product built on C# and Microsoft SQL Server, maintaining and extending long-standing systems.
  • Greenfield Platform Co-built "Platform Manager" from scratch with another engineer — the internal system for administering the GPS trackers and cameras the company installs in customer vehicles. Built on early React with a Node.js and AWS Lambda backend and MySQL.
Apr 2017 — Aug 2018
Web Developer
Vectorial
  • Enterprise Platforms Built and maintained a multi-tenant corporate employee performance review and appraisal platform using Ruby on Rails, Angular, and MySQL.
  • Agile Delivery Delivered customized software architectures tailored to diverse client specifications in a fast-paced agency environment.
Jul 2013 — Feb 2017
Web Project Leader & Developer
Sigma Móvil SAS
  • Product From Scratch Co-built a mass email marketing SaaS platform as one of the two core junior developers on a 3-person team, scaling the product from inception to commercial viability.
  • Monolithic Architecture Developed a unified full-stack application using Phalcon PHP, Ember.js, and MySQL.
  • Feature Engineering Designed and coded a complex drag-and-drop email template editor and an optimized contact-ingestion pipeline integrated with high-volume MTAs for massive email deployment.

Independent Projects

A few of my largest independent builds. There are more, but these are the ones that mean the most to me.

Transportes Ejecutivos
Ecosystem

A B2B company offering corporate transportation services — and one that runs its entire operation on the platform I built and still maintain. From the web dashboard the team creates and dispatches services with their passengers and pickup addresses, administers passenger, vehicle, and driver records, and automatically flags when a vehicle's or driver's documentation falls out of date, all backed by reporting. I also built a REST API for third-party integrations, a native Android app for drivers, and a React Native app for passengers.

D Side
Internal Operations Platform

Developed an internal task management and operational traffic platform using Laravel (PHP) and Vue.js. Engineered a custom budget estimator tool embedded with complex pricing formulas to optimize client billing accuracy and increase profitability.

Technologies

Education

2015 — 2019
Systems Engineer
Corporación Universitaria Centro Superior
2009 — 2012
Associate Degree in Computer Science
Universidad Autónoma de Occidente