ESC
Senior Full-Stack Software Engineer

Twelve years shipping
production software.

I do not write code that lives in slides.I write code that lives in servers to help people and business.

About me
Izmir Sánchez
Name
Izmir Sánchez
Role
Senior Full-Stack Software Engineer
Location
Mexico
Status
Available
Uptime
12+ years
Shell
zsh / bash
Editor
Neovim / Zed / Vscode
OS
Debian / Ubuntu
S/N: 1337-DEVELOPER

I build software that makes it to production

For more than 12 years, I've been turning ideas into real products — from mobile and web applications to APIs and backend systems. My work has shipped to app stores, supported logistics operations, and been used on offshore oil platforms. I care about more than making things work today. I build systems that can evolve, APIs that teams can rely on, and code that makes sense to the engineer who has to maintain it tomorrow.

Experience
12+YearsShipping production software across web, mobile, and backend.
500+UsersOffline-first field apps running on oil rigs without connectivity.
End-to-EndDeliveryFrom requirements gathering to production deployment, every time.
Nov 2025 — Present

IT Partners (Traxion)

Senior Full-Stack Developer

Context

One of Mexico's largest logistics operators. Thousands of trucks, hundreds of field crews, zero tolerance for downtime.

Problem

The tools in use struggled with technologies requiring specialized implementation, making it necessary to use tools that enabled rapid iteration on new features.

Solution

I was part of the team modernizing tools for operators and coordinators of the Mecanix and Mi Copiloto platforms, for both Android and iOS. I implemented a resource gateway for both applications that helped maintain information consistency across them. I established CI/CD pipelines that deploy to servers without human intervention. I also contributed to developing modules for the web versions.

Impact

Implementing new modules alongside AI tools became more efficient, and configuring the CI/CD tools allowed these new modules to become available to users in less time.

Tech

React Native, Fastify, PostgreSQL, Docker, GitHub Actions, Ubuntu, Claude Code, Codex, Opencode, Firebase

Result

Applications in production. Zero manual deployment. Paper eliminated.

Feb 2016 — Present

Independent

Freelance Software Engineer

Context

Clients who need working software, not presentations. Startups, SMEs, and internal tools for teams that outgrew spreadsheets.

Problem

Most vendors sell roadmaps. Clients needed someone who could own the entire lifecycle — architecture, code, deployment, maintenance — without a team of ten.

Solution

Operated as a one-person engineering team. Designed full-stack architectures from scratch. Implemented REST APIs consumed by web and mobile clients. Integrated legacy systems like VICIdial into modern CRM workflows. Built CI/CD from day one so shipping was never an event.

Impact

Every project shipped. Some became the core revenue system of the client. Others replaced processes that had been manual for a decade.

Tech

React, Node.js, PostgreSQL, REST APIs, CI/CD, Clean Architecture

Result

Software that still runs years later without rewrites.

Aug 2021 — Jun 2024

Saeko

Mobile / Web Developer

Context

An education platform used by schools and parents. The previous team had left the codebase unstable and the ratings were catastrophic.

Problem

The app had a 2.4-star rating. Push notifications failed. Performance was unacceptable on mid-range Android devices. Users were uninstalling.

Solution

Rebuilt critical navigation and sync paths. Implemented a reliable push notification pipeline. Stabilized the React Native codebase. Profiled and eliminated frame drops on low-end hardware.

Impact

App store rating climbed from 2.4 to 4.3. Uninstall rate dropped. Support tickets related to crashes decreased by 80%.

Tech

React Native, Performance Tuning, Push Notifications, Firebase

Result

The app still runs today. No rewrite needed.

Jun 2019 — Aug 2021

Cotemar

Mobile / Web Developer

Context

Offshore oil rigs in the Gulf of Mexico. No Wi-Fi. No 4G. Harsh environments. Safety-critical operations.

Problem

Field teams could not access operational data while offshore. Every form, inspection, and safety check had to be done on paper and transcribed later. Errors were frequent and dangerous.

Solution

Built offline-first mobile and desktop applications with React Native and Electron. Designed a sync engine that queues work locally and pushes massive datasets when the device returns to connectivity range.

Impact

500+ workers accessed critical operational data daily. Inspections became digital. Errors dropped. Sync happened automatically when crews returned to port.

Tech

React Native, Electron, Offline-First, Sync Engine, REST APIs

Result

Operations continued without connectivity. Data integrity maintained.

Published apps

Software people can install.

A selection of production mobile apps I have contributed to, available on Google Play and the App Store.

Mecanix-e

Grupo Traxion

Fleet maintenance and vehicle status tracking for Grupo Traxion.

View on Google Play iOS app for closed use

Mi Copiloto

Grupo Traxion

Employee app with vehicles, announcements, activities, trips, and service appointments.

View on Google Play iOS app for closed use
Stack

Production-proven stack.

Technologies grouped by domain. Bars show years of real production experience. No tutorial projects.

Frontend

Interfaces that survive poor networks, old devices, and impatient users.

  • TypeScript
    4y
  • React
    8y
  • React Native
    6y
  • Next.js
    2y
  • Astro
    2y

Backend

APIs that keep their contracts and handle load without surprises.

  • Node.js
    10y
  • NestJS
    2y
  • Fastify
    2y
  • PHP
    4y

Database

Data models that make sense six months later.

  • PostgreSQL
    8y
  • MySQL
    10y

DevOps

Shipping should be boring, not an event.

  • Docker
    2y
  • GitHub Actions
    3y
  • Linux
    12y

Mobile

Apps that survive real-world conditions — poor signal, old phones, harsh environments.

  • Expo
    4y
  • Electron
    3y

Architecture

Decisions that cost less to undo later.

  • Clean Architecture
    6y
  • SOLID
    3y
  • CI/CD
    4y

Every technology listed above has been used in production. No "played with it once" entries. No tutorial projects. Only tools that have shipped real software to real users.

Philosophy
Clean Architecture over clever hacks.

I have inherited enough quick fixes to know they always outlive their welcome. I separate concerns so the business logic survives framework updates, team changes, and the passage of time. The code I write today should not become the technical debt someone else dreads tomorrow.

Software exists to solve business problems.

The best abstraction is the one that maps to how the business actually works. I start with the problem, not the technology. I have seen over-engineered systems that looked elegant on diagrams but failed in production because nobody asked what the user actually needed.

Maintainability is a competitive advantage.

Fast delivery means nothing if the next feature takes three times longer. I write code with the next engineer in mind — clear naming, consistent patterns, and tests that explain intent. A codebase should get easier to work in over time, not harder.

Performance is not premature optimization.

When a field worker is waiting for an app to sync on a 3G connection in the middle of nowhere, every millisecond matters. I measure before I optimize, but I never ignore performance as a feature. It is the difference between software people use and software people tolerate.

The tools change. The principles do not.

I have shipped with jQuery, Angular, Vue, and now React. Frameworks come and go, but the fundamentals — separation of concerns, clear interfaces, testing — stay. I learn new tools when they solve real problems, not because they are trending.

These are not slogans. They are constraints I use to make decisions under pressure.

Currently

What I am doing right now.

Building

Development and modernization of internal systems used by call center teams, implementing modern technologies to optimize processes, improve user experience, and simplify daily operations management.

Learning

AI, LLMs, and MCP — Exploring and implementing solutions based on artificial intelligence, LLMs, and MCP resources to continuously improve business processes and optimize software development workflows.

Exploring

Local-first software architecture and CRDTs for offline collaboration.

This section updates as my focus shifts. Last modified: 2026-08-10.

Contact

Available for select engagements.

If you are building something that matters, and you need someone who can own the full stack — architecture, implementation, deployment, and maintenance — send a signal.

If the inbox is full, try the terminal. Type sudo hire dfkuro.