Paolo Castro
paolo@calgary:~$ whoamiCalgary --:-- MT51.05° N, 114.07° WEngineering since 2010

Platforms that hold up

Portrait of Paolo Castro

I'm a principal software engineer. I build web platforms and the services behind them, most recently clinical research systems at Vial, working alongside AI agents every day.

Role
Principal Engineer, Vial (joined 2022)
Core
TypeScript, Node.js, React, Next.js
Data
PostgreSQL, MongoDB
Infra
GCP, Docker
AI Tooling
Claude Code, opencode, Cursor
Also
Python, Java, Ruby
work4 entries

The platform I build, and the products I run.

IDProjectTypeStatus
001

CRO Platform

PlatformIn production

An in-house clinical-trial system at Vial: a backend API, two web frontends and Cloud Run jobs, built by teams of up to 15 engineers and used across 10+ trials. I set the technical direction and built core parts, including the trial setup admin platform. Private.

Stack
Node.jsTypeScriptPostgreSQLGCP
Infra
Google Cloud, managed with Terraform: Cloud Run, Cloud SQL, Cloud NAT with private IPs, Cloud Logging, Firestore, Vertex AI
Delivery
I own CI/CD and workflows, including end-to-end test orchestration with a Cypress test matrix
Monitoring
Sentry and PostHog, integrated to watch platform performance and catch issues
Lab data
Claude skills and Python cut lab-data turnaround from 1–2 weeks to 1–2 days
002

Poolville

Web appLive

Sports pools for friends, family, colleagues and deadly enemies. Co-maintained since a full rewrite, updated for every World Cup, Copa América and Euro.

Stack
MeteorNode.jsMongoDB
poolville.co
003

Parlo

Web appLive

Colloquial phrases across three languages, shown the way locals actually say them. A practice platform for newcomers.

Stack
Next.jsTypeScriptMantine
Translation
An in-app tool that translates phrases with an LLM, which keeps the meaning where a word-for-word translation breaks
parlo.fun
004

ZeroDrift

iOS appSide project

A simple iOS task tracker that keeps you moving forward. My own experiment with iOS development.

Stack
SwiftUISwift
View on GitHub
contactOpen to principal and staff roles

Let's talk.