JC
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Juan Cruz Marquez
hi, I'm

Juan Cruz Marquez

Sr Software Engineer

Fig. 1. 4,715 contributions, 28 Sept 2025 – 27 Sept 2026. Source: GitHub.

About

I'm an engineer who builds software end to end, from the first idea to production. I care about clear architecture, reliable systems and products that feel simple to use.

I've worked on web platforms, APIs, AI integrations and process automation, for startups and large companies alike. What I enjoy most is turning messy problems into tools people rely on every day.

Computers have been my thing since I was a kid.

Juan Cruz as a kid, using the mouse at a Philips computer.
Day one.
Juan Cruz as a kid, seen from behind, playing a Disney game on a beige PC.
Never looked back.

Stack

Languages
TypeScript
JavaScript
Python
Java
C++
Backend
Node.js
NestJS
PostgreSQL
Frontend
React
Next.js
Tailwind CSS
Cloud & tools
Docker
AWS
Cloudflare
Azure Service Bus
Git
AI & process
LLM APIs
Claude
Codex
Scrum
Automation (RPA)
Automation Anywhere
UiPath

Experience

  1. Chelsea Labs

    Current

    Senior Full Stack Engineer

    Mar 2026 — Present
    • Design and build full stack features for SaaS products, from the data model to the user interface.
    • Lead backend architecture decisions and integrate AI models into production workflows.
    • Build process automation solutions for clients in regulated industries.
    • TypeScript
    • NestJS
    • React
    • PostgreSQL
    • Docker

  2. VEMO

    Full Stack Developer

    Jul 2023 — Dec 2024
    • Led backend development of an operations management platform for scheduling and workforce planning.
    • Built the authentication and authorization service: users, roles and permissions.
    • Designed event-driven integrations between services using message queues.
    • TypeScript
    • NestJS
    • PostgreSQL
    • Azure Service Bus
    • Docker

  3. KPMG

    Full Stack Developer

    Mar 2022 — Jul 2023
    • Developed backend services and web applications for internal and client-facing solutions.
    • Automated document processing, extracting data from PDF files into databases.
    • TypeScript
    • NestJS
    • React
    • Tailwind
    • Python

  4. UTN

    Tutor

    Mar 2023
    • Mentored students in the Testing Argentina 4.0 program, reviewing their practical work and coordinating teams.

  5. Casa Vila

    Full Stack Developer

    2019 — 2022
    • Built an inventory management system with real-time stock tracking, sales and reporting.
    • Python
    • React
    • PostgreSQL

Projects

Education

  • Systems EngineeringUniversidad Tecnológica Nacional (UTN)2019 — 2025
  • High School Diploma in Economics and AdministrationInstituto La Santísima Trinidad2008 — 2014

Beyond code

When I'm not writing code, I , , and .

And I'm a die-hard fan of Lionel Andrés Messi Cuccittini10

A large graphite drawing of a veiled face.
Me next to a large portrait I drew.
Drawing a study of hands in pencil.
My drawings on the walls of an exhibition.
Me in front of the Mona Lisa.

Graphite and charcoal, mostly portraits. Some of them were shown at an exhibition.

Me playing a keyboard.

I studied music. I play guitar and piano.

Influences

  • Charly García
  • Gustavo Cerati
  • The Beatles
  • Led Zeppelin
  • Stevie Wonder
  • Michael Jackson
  • Tool
  • Arctic Monkeys
  • James Brown
  • and many more
Boca Juniors
Boca fans with flares in the stands.
La Bombonera packed, with a giant club flag.

Blue and gold since forever.

Counter-Strike 2 key art.

Mostly competitive ones, CS2 above all.