Available for Work

Alexander Castro

Software Developer · Full-stack

I specialize in solving complex engineering challenges, delivering scalable solutions that optimize performance, UX, and system architecture.

TypeScript across the whole stack: NestJS, React, Next.js and React Native. Experienced with AWS, GCP, Firebase and SQL/NoSQL databases, plus Tailwind CSS, shadcn/ui, TanStack Query and AI-powered features with LLMs.

Alexander Castro, full-stack developer, portrait

Years of Experience

Bello, Antioquia

Technologies

I have experience in a wide range of technologies

Experience

Professional Milestones

Full Stack Developer
Oct 2024 - Dec 2025

Visit Logali Group

Grupo Logali

Full Stack Developer
APR 2023 - OCT 2024

Visit Eco2

Programing professor
Oct 2023 - Dec 2023

Visit Intech

Technology Integrator
Jun 2023 - dic 2024

Visit TICS

Content Creator, social media manager and mentor
Jun 2022 - dic 2022

Visit NGN

Projects

Some of my projects

CVL — Circuito Voleibol Llanero

CVL EcosystemRealtime Platform

Next.js
NestJS
Socket.IO
Prisma
PostgreSQL
TypeScript

Real-time platform that runs the stage-based volleyball circuit of the Meta region (Colombia), replacing a manual Excel + Forms + Looker workflow. Live scoring pushed over Socket.IO, automatic standings and circuit ranking, club registration, and a framework-agnostic tournament engine kept pure and fully tested against the official rulebook. Built as a Turborepo monorepo: NestJS + Prisma + PostgreSQL + Redis API and a mobile-first Next.js PWA with shadcn/ui, Better Auth RBAC and Zod contracts, self-hosted with Docker on a VPS via Coolify. Private source code, live in production.

~/api-server

server running

$NestJS Modular Monolith✓

$Prisma + PostgreSQL✓

$Better Auth Sessions✓

$DTO Validation✓

$Redis/BullMQ Ready✓

$LATAM SaaS Architecture✓

NestJSPrismaPostgreSQLDockerTypeScript

Turnio API — SaaS Scheduling Backend

Turnio EcosystemAPI

NestJS
Prisma
PostgreSQL
Docker
TypeScript

Monolithic NestJS API for service businesses in LATAM. Includes modular domains (Auth, Business, Appointments, Clients, Services, Schedules), Prisma ORM with PostgreSQL, Better Auth session flow, DTO validation, and Redis-ready queues for async reminders.

Turnio Web — Booking Experience

Turnio EcosystemWeb BookingDepends on: Turnio API

Next.js
Tailwind CSS
TypeScript

Public booking website for Turnio where end customers can discover businesses and reserve appointments online in a clean, mobile-first flow. Designed to work alongside WhatsApp-first communication and fast onboarding for small businesses.

PróximamenteEn desarrollo activo

Turnio Mobile App — Owners & Staff

Pronto

Turnio EcosystemMobile AppDepends on: Turnio API

React
Expo
TypeScript
Zustand

Mobile app for business owners and workers to manage schedules, appointments and clients with an offline-first approach. Built with Expo, React Native, TypeScript, Zustand, local persistence and sync when the connection is restored. It is currently in Google Play private testing and should be available to the public in about 8 days once the mandatory test window is completed.

~/api-server

server running

$MercadoPago Webhooks✓

$JWT Auth & RBAC✓

$Prisma ORM✓

$Docker Compose✓

$REST API✓

$Subscription Management✓

NestJSPrismaPostgreSQLDockerTypeScriptMercadoPago

Atlex API — Backend Services

Atlex EcosystemAPI

NestJS
Prisma
PostgreSQL
Docker
TypeScript
MercadoPago

RESTful API powering the Atlex club management platform. Built with NestJS, Prisma ORM, PostgreSQL and Docker. Features MercadoPago webhook integration for real-time payment processing, JWT authentication, role-based access control, and automated subscription management. Currently in active development.

Atlex 1.0 — Club Management Platform

Atlex EcosystemWeb PlatformDepends on: Atlex API

Next.js
TypeScript
Tailwind CSS
MercadoPago

Atlex is a club management platform designed to streamline administrative tasks and enhance member engagement. This project was developed using NestJs, Postgrest, Next.js, React, Tailwind CSS, and integrated with MercadoPago for seamless payment processing.

~/api-server

server running

$SSE Streaming✓

$Multi-Provider (Groq, Cerebras, Ollama)✓

$Provider Rotation✓

$OpenAI Message Format✓

$/chat Endpoint✓

$Vercel Deployment✓

BunTypeScriptOpenAI

Bun Streaming LLM API

Bun
TypeScript
OpenAI

Minimal Bun API that exposes a /chat endpoint with Server-Sent Events (SSE) streaming. Supports multiple LLM backends (Groq, Cerebras, and local Ollama) with provider rotation per request, making it easy to swap or compare models while keeping a single OpenAI-style message format. Deployed on Vercel.

Storyteller ai for kids

Next.js
Tailwind CSS
AWS
OpenAI

Storyteller is an artificial intelligence tool designed to generate stories for children. This project was created using Next.js, React, serverless, aws and Tailwind CSS.

MarIA - MVP | IAS Ecosystem.

Next.js
Tailwind CSS
Strapi

IAS management ecosystem. Created from scratch and together with the Eco2 team, using Next.js, React, strapi and Tailwind CSS.

Uber Clone — Ride-Hailing App

React
Expo
TypeScript

A modern Uber clone built to learn and demonstrate real-world ride-hailing features like real-time location tracking, trip management, and scalable app architecture. Built with Expo, React Native and Bun.

~/api-server

server running

$Multi-Tenant Architecture✓

$Keycloak SSO✓

$Role-Based Auth✓

$Expense Workflows✓

$File Uploads✓

$Offline Sync Support✓

NestJSPostgreSQLKeycloakDockerTypeScript

Workforce API — Logali Group

Workforce EcosystemAPI

NestJS
PostgreSQL
Keycloak
Docker
TypeScript

Multi-tenant RESTful API built for the Workforce enterprise platform. Developed with NestJS, PostgreSQL, and Keycloak for SSO authentication. Features multi-tenant data isolation, role-based authorization (technician, contractor, coordinator, accountant), work order lifecycle management, expense approval workflows, and file upload handling. Designed for offline-first mobile sync.

Workforce Admin — Logali Group

Workforce EcosystemWeb AdminDepends on: Workforce API

Next.js
Tailwind CSS
TypeScript

Web admin panel for the Workforce platform at Logali Group. Enables administrators to create and assign work orders, manage technicians, approve expenses and travel allowances, generate Excel reports from field data, assign job sites, and manage clients. Includes role-based access for coordinators and accountants. Built with Next.js, React and TypeScript.

Workforce — Logali Group

Workforce EcosystemMobile AppDepends on: Workforce API

React
Expo
Redux Toolkit
TypeScript

Enterprise mobile app for field workforce management with offline-first architecture. Features expense tracking, attendance, work order management, report generation with image uploads, and Keycloak authentication. Built with Expo, React Native, Redux Toolkit, and SQLite for robust offline data sync. Available on Google Play Store.

Like Trello app

Next.js
Tailwind CSS
AWS

Like Trello is a web app that allows you to create boards, lists and cards. This project was created using next js, aws amplify, dynamoDB, tailwind CSS. I stopped working the BD because of the cost, but if you want i can re-enable it, just let me know.

Courses Landing Page

Next.js
Tailwind CSS

Landing page for a course platform. This project was created using Next js, Tailwind CSS.

CopyGenius - Co:here Hackaton 2023

Next.js
Tailwind CSS

CopyGenius is an artificial intelligence tool designed to generate effective marketing copy, it also integrates other functionality to create product descriptions. CopeGinius web app created using next js, in order to participate in the co:here hackaton of midudev. Actually is not working bacause need to pay the API.

Encripter app

Tailwind CSS
React

Encripter app is a web app that allows you to encrypt and decrypt messages using the Caesar cipher. This project was created using React, Tailwind CSS and Github pages.

Metacritic Clone

Tailwind CSS
React

Metacritic clone is a mobile app, web app that allows you to search for movies and series, see their ratings and reviews. This project was created using React native, Natiwind CSS.

Calculator clone

React

Calculator clone is a mobile app, web app that allows you to perform basic mathematical operations. This project was created using React native