Español English
Andres Diago
Available for projects

Hey, I'm Andres Diago

+3 years building backends and products. Full-stack & AI systems engineer from Popayán, Colombia 🇨🇴. Node.js/NestJS, Go, Next.js, PostgreSQL and AWS.

Experience

  1. •

    Senior Backend Developer

    TBBC · Popayán

    Event-driven microservices for banking systems: core banking integration (SOAP), the PSE payment gateway, notifications (Twilio SMS, FCM) and Active Directory/LDAP. JWT + OAuth2 auth, AWS Secrets Manager and API Gateway, high-throughput MongoDB, blue-green auto-scaled deployments on AWS ECS, CloudWatch observability and Python/FastAPI microservices for AI features.
  2. •

    Backend Engineer

    Simplixity

    Multi-service backend for a multi-tenant WhatsApp messaging platform. Event-driven architecture with BullMQ/Redis, Meta WhatsApp Business Cloud API and OpenAI Assistants API integrations, multi-tenant MongoDB, deployment on AWS EC2 with Docker and PM2, CI/CD with GitHub Actions.
  3. •

    Backend Developer · Data Integration

    TBBC · Popayán

    ETL pipelines with Node.js/Express and MongoDB/Mongoose services with complex aggregations. AWS integration (S3, SNS, SQS, Lambda) and resilience patterns: exponential backoff, idempotency and circuit breakers.
  4. •

    Backend → Full Stack Developer (internships)

    Universidad del Cauca

    Two internship periods: backend first (03/2022 – 08/2022), then full stack (08/2022 – 01/2023). Modeled a real problem at the university and delivered a web application deployed on on-premise servers.

Projects

connectHUB — The Unconnected Foundation

connectHUB — The Unconnected Foundation

  • Next.js
  • NestJS
  • PostgreSQL
  • AWS
Multi-tenant portal to manage Starlink connectivity for humanitarian deployments across six countries. Turborepo monorepo with Next.js (App Router) and NestJS on AWS, per-organization Row-Level Security and RBAC, integrated with the Starlink API. Serves 3,000–4,600 service lines.
AI-assisted bookkeeping SaaS

AI-assisted bookkeeping SaaS

  • NestJS
  • Next.js
  • PostgreSQL
  • AWS
  • Client under NDA
Beta product for small-business owners and accounting firms. I built the bank-statement pipeline integration: the PDF lands in S3, is extracted with AWS Bedrock, and every transaction is categorized against the chart of accounts by four engines in parallel (learned rules, two RAG backends on pgvector and an LLM classifier), with a per-transaction review view and an internal trainer that feeds corrections back into the vector store. Also the 6-role permission model with audited money permissions, the multi-client dashboard for firms and the registry of 160+ notification scenarios. NestJS 11, TypeORM, PostgreSQL 16, Next.js 16, Plaid, Stripe, Everee.
Lead-management CRM with Power Dialer

Lead-management CRM with Power Dialer

  • NestJS
  • Next.js
  • Redis
  • AWS
  • Client under NDA
Production SaaS for lead management (forms, automated calls and SMS, subscriptions). I integrated the Power Dialer module into the dashboard (campaigns, live calls, recordings, role-based ACL) and deployed the system on AWS EC2 with Docker Compose, Nginx + TLS and GitHub Container Registry. NestJS 10, replicated MySQL, Bull + Redis, Socket.IO, Twilio (voice, SMS, A2P 10DLC), Stripe, a Puppeteer scraping microservice and a shared contracts library on AWS CodeArtifact.
Simplixity Chat

Simplixity Chat

  • React
  • Node.js
  • Express
  • Redis
Multi-tenant SaaS WhatsApp messaging platform with real-time chat. Integrates Meta's WhatsApp Business API, asynchronous processing with BullMQ and Redis, and automated replies with OpenAI Assistants bots. React + TypeScript frontend, Node.js + Express backend with PostgreSQL.
Movies App

Movies App

  • Next.js
  • Tailwind
Movie PWA built with Next.js 15 and Tailwind on top of the TMDB API: search, details and browsing by genre. Personal project.

Open source

Merged contributions to tooling for coding agents.

Graphify-Labs/graphify

Turns codebases, docs and schemas into a knowledge graph that agents can query. Python.

Python
  • #4391 — the shrink guard dropped semantic nodes that had been deduplicated into their AST twin on rebuild; tightened the exemption, folded LLM node/edge field aliases and added end-to-end regression tests with a negative control. View PR →
permgps/herdr-telegram-agents

Control coding agents (Claude Code, Codex, opencode) from Telegram. Go.

Go
  • #13 — CodexReader: locates the Codex thread's rollout file and returns the last turn's final answer instead of the terminal tail (~2,000 lines incl. tests). View PR →
  • #11 — the daemon opened a console window per child process on Windows; CREATE_NO_WINDOW helper plus a CI check that rejects new direct exec.Command calls. View PR →
  • #9 — the PowerShell installer failed to hash the release when launched from pwsh; hash via .NET instead. View PR →

About me

I'm an Electronics and Telecommunications engineer from Universidad del Cauca, and I've spent the last three-plus years building software: today, event-driven banking backends at TBBC, a messaging platform at Simplixity, and products for US clients as a freelancer.

Most of my work is designing services that integrate third-party systems (payments, telephony, banks, AI APIs) without breaking under load, and taking AI features to production with RAG, multi-engine scoring and human review. I work in TypeScript, Go and Python; PostgreSQL, MongoDB and Redis; AWS and Docker.

I contribute to open-source tooling for coding agents (graphify, herdr) and founded Apolocode SAS, through which I deliver projects with a small distributed team. I work in English and Spanish.

Andres Diago