Nicolás Alarcón — Backend Developer | NestJS, RabbitMQ, Microservices

Nicolás Alarcón

Full-stack Developer

Full-stack developer focused on backend systems, APIs and distributed architectures. I have built messaging services, automation and administration tools for production products and independent projects. I also integrate AI into my development process, using it to analyse problems and shape solutions as well as carry out implementation tasks.

Experience

Professional experience and independent projects where I have designed, built and shipped software systems.

Factor Studios - Dragonchat

Remote Backend Developer

2024 - April 2026

I developed an internal library in NestJS for sending requests and logging, integrating Loki.
Complete refactoring of the core logic for sending text messages via WhatsApp, moving control from the Frontend to the Backend by implementing queues with RabbitMQ between microservices.
I implemented a storage system for user files with Supabase.

I developed an internal Feature Flags tool to facilitate deployments, allowing selective activation or deactivation of functionalities by feature, user, or user type.
I optimized resource usage in microservices using AsyncLocalStorage to handle a context per request, avoiding class instantiation for each request.

I developed an internal library in NestJS for sending requests and logging, integrating Loki.
Complete refactoring of the core logic for sending text messages via WhatsApp, moving control from the Frontend to the Backend by implementing queues with RabbitMQ between microservices.
I developed an internal Feature Flags tool to facilitate deployments, allowing selective activation or deactivation of functionalities by feature, user, or user type.
I optimized resource usage in microservices using AsyncLocalStorage to handle a context per request, avoiding class instantiation for each request.
I implemented a storage system for user files with Supabase.

PDF Vault - Freelance Project

Full Stack Developer · AI-assisted SDD

September 2026

Led development with Claude using Spec-Driven Development: translated client requirements into functional specifications, technical designs, scoped tasks and acceptance criteria before implementation.
Used skills and agents guided by project instructions in AGENTS.md and CLAUDE.md to keep implementation aligned with the specs and reserve product decisions for human review.
Built separate reading and backoffice applications backed by an ASP.NET Core API and PostgreSQL.
Implemented authenticated delivery of versioned documents from private storage, along with version administration and access metrics.
Prepared a traceability matrix linking acceptance criteria across 13 specifications to their verification.

Media Pipeline - Independent Project

Full Stack Developer

2026 - Present

Built a full-stack platform that turns an anime catalogue into an automated media library, with a Next.js frontend and ASP.NET Core APIs backed by PostgreSQL.
Developed background processes to discover and update titles and episodes, coordinate downloads and prepare media for playback; the system runs 18 background processes.
Implemented user features including catalogue search and browsing, anime details, episode streaming, personal lists, reviews, comments and watch-progress tracking.
Built admin tools to manage downloads and availability, review folder-to-media matches with live SignalR progress, and translate metadata with Ollama.

Projects

Media Pipeline - Independent Project

My most ambitious project: a platform that turns an anime catalogue into an automated media library. It discovers and updates titles and episodes, manages downloads, and prepares content for playback, with 18 background processes coordinating catalogue, availability, and operations tasks. From an admin panel, I can monitor activity, manage the download queue, and oversee the library. It also includes AI-powered translation of data such as descriptions, episode streaming, personal lists, and per-user progress tracking. Users must sign in to access features such as viewing episodes, commenting, and managing their media list.

C#.NETPostgreSQLEF CoreSignalRDockerNextJSTypeScript

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Home

Landing page with featured anime, seasonal releases and recently added titles.

PDF Vault - Freelance Project

An application for managing a PDF document with version control: the team can publish updates and roll back to a previous version. The client wanted readers to access it without creating or remembering a password, so I built a platform where entering an email address is enough to sign in, with a separate backoffice for managing users and document versions. The ASP.NET Core API delivers the PDF only through an authenticated session: there is no public file route, and the storage key never reaches the browser.

C#.NETPostgreSQLEF CoreIdentityNextJSTypeScriptDocker

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User portal sign-in before readers can access the document.

Dragonchat - Backend Developer at Factor Studios

Mass messaging platform over WhatsApp, built on a microservices architecture. I designed and implemented the backend system to scale message delivery, moving the logic from the frontend to the backend using RabbitMQ queues, which made it possible to pause, resume and edit campaigns in real time. I also built the internal feature flags service and the observability library with Loki.

TypeScriptNestJsRabbitMQRedisDockerNextJSMySQLSupabase

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Dragonchat

Mass messaging platform via WhatsApp, send messages to your contacts once, and we take care of the rest.

Technologies and tools

Backend

I specialise in backend systems that need to run reliably in production. I work with NestJS and ASP.NET Core on PostgreSQL, integrating queues and background processes. In Media Pipeline, I operate 18 background processes and a pipeline that preserves its progress and resumes after a restart. I am also currently studying Java with Spring Boot.

JavaScript

TypeScript

.NET

Java

NodeJs

NestJS

Spring Boot

Docker

Nginx

Git

GitHub

Claude

PostgreSQL

MySQL

Redis

Postman

Frontend

I also build interfaces with React and Next.js, making sure they adapt well to different screen sizes. For the media platform, I developed a responsive operations panel with real-time progress over SignalR and tools for reviewing matches; I also designed and maintain this portfolio.