SOFTWARE ENGINEER

Building production-grade web, mobile, and cloud backend solutions with .NET, React, React Native, and Supabase. Clean architecture, high performance, and great user experience.

5+

Years Experience

3+

Projects Shipped

sebastian@portfolio:~
$ whoami

Sebastian De Leon — Computer Engineering Student @ WMU

$ cat stack.txt

languages TypeScript · JavaScript · C# · Python · SQL · C · C++

frontend  Next.js · React · React Native · Tailwind CSS

backend   ASP.NET Core (.NET 9) · CQRS · DDD · EF Core

mobile    React Native · Expo · Jetpack Compose

database  PostgreSQL · MS SQL Server · Supabase

devops/toolsGit · Docker · Linux · Edge Functions

$ echo $status

Open to new opportunities ✓

█

Experience

Reispsolutions S.R.L.

Reispsolutions S.R.L.

Junior Software Engineer

  • ▸Architected a distributed Learning Management System (LMS) for a multi-brand restaurant corporation in the Dominican Republic, scaling training infrastructure across dozens of branch locations using ASP.NET.
  • ▸Built production-oriented ASP.NET Core services with .NET 9, CQRS, DDD, and Clean Architecture, implementing controllers, application services, domain models, and EF Core persistence across multiple backend services.
  • ▸Developed an end-to-end clinical management web application that automated patient intake flows, integrated calendar scheduling, and deployed automated SMS/email reminders for upcoming appointments.
  • ▸Worked on self-service Android kiosk applications for large-format tablets across multiple restaurant brands, leveraging Jetpack Compose to deliver a highly responsive, modern, and intuitive in-store ordering experience.
Apolo 27 (INTEC — NASA HERC Team)

Apolo 27 (INTEC — NASA HERC Team)

Manufacturing & Telemetry Assistant

  • ▸Designed and implemented Task A for the 2025 NASA HERC rover: a lead-screw actuator driven by a stepper motor that moved a sensor vertically to detect whether a container holding liquid contained water.
  • ▸Built the rover control system around an ESP32-S3, reading PWM signals from a commercial RC receiver and implementing a state machine to map controller inputs to rover motion and task execution.
  • ▸Contributed to a rover platform that traversed simulated Mars and Moon terrain while performing mission tasks under competition constraints (1st place overall in RC Division).
  • ▸Led the full-stack architecture for the official Apolo 27 website, including frontend and backend development.
  • ▸Managed the development of proprietary games and digital tools for STEM outreach across the Dominican Republic.
Bioingenious Smart Solutions S.R.L

Bioingenious Smart Solutions S.R.L

Biomedical Technician

  • ▸Collaborated in medical surveys in hospitals and maintenance of clinical equipment.
  • ▸Programmed the company's website, successfully integrating it with Odoo ERP database for real-time workflows and custom automated invoicing.

Projects

Velo: Movie Matchmaker

Velo: Movie Matchmaker

Cross-platform Expo/React Native movie matchmaking app with Clean Architecture, Zustand, Supabase Realtime, weighted voting, veto logic, and multi-language support.

React NativeExpoTypeScriptZustandSupabase
Printune

Printune

Full-stack Next.js/FastAPI tool converting Spotify track, album, and playlist URLs into personalized 3D-printable keychains with Three.js orbit previews and STL export.

Next.jsTailwind CSSThree.jsPythonFastAPI
Apolo 27 Website

Apolo 27 Website

Official website for the Apolo 27 team competing at NASA's Human Exploration Rover Challenge (HERC).

Next.jsTailwind CSS
Clinical Management System

Clinical Management System

End-to-end clinical management application automating patient intake flows, calendar scheduling, and automated SMS/email reminders.

ReactTailwind CSSMongoDBExpressNode.js
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Minevers

Interactive web tool to explore and compare new features, biomes, and changes across Minecraft versions.

React