Rhay ParraSoftware Developer and Architect

Full-stack architecture and hands-on engineering for startups building on Node.js, AWS and AI.

I design the system, write the decision record, and then write the code. Currently a senior architect at a US advocacy platform and founder of Loxben Apps, working remotely from Montevideo.

Selected work →Notes

Since
Shipping production software since 2012
Stack
TypeScript, Node.js, Python, AWS
Now
Senior architect, US advocacy platform
Where
Remote from Montevideo · ES/EN

Selected work

A few problems I've worked on recently — what was actually wrong, what it took, and what it cost.

  • Managed scanning for HIPAA uploads

    Problem
    Claimants needed to upload medical records into a system where one missed malware file or one mishandled image is a compliance incident.
    Outcome
    Replaced the planned ClamAV sidecar with managed scanning, moderation and an Object Lock quarantine; worker memory went from 8 GB to 2 GB and monthly scanning cost dropped ~90%.
    • NestJS
    • AWS CDK
    • S3 + KMS
    • GuardDuty
    • Rekognition
    • EventBridge

  • Chat-led app beside the dashboard

    Problem
    Add a conversational interface to a customer app without a rewrite, without exposing credentials to the browser, and without losing the audit trail.
    Outcome
    Next.js Multi-Zone apps behind a NestJS gateway, streaming tokens from Lambda Function URLs; designed to a sub-500 ms first-token budget.
    • Next.js
    • Vercel AI SDK
    • NestJS
    • Lambda
    • Nx

  • A 1,000× bandwidth spike on Vercel

    Problem
    Video served from a Vercel-hosted Next.js site went from 32 GB/month to 32 TB in nineteen days; cache headers changed nothing.
    Outcome
    Moved media delivery off Vercel's network to CloudFront + S3 with rate limiting; projected 97–99.7% lower delivery cost.
    • Next.js middleware
    • Vercel WAF
    • CloudFront
    • S3
    • AWS

  • Salesforce events that stopped arriving

    Problem
    Platform-event subscriptions went silent after days of uptime, with no errors and a green health check.
    Outcome
    Traced to the CometD transport itself, shipped watchdog and replay-ID mitigations, and specified the migration to the gRPC Pub/Sub API.
    • NestJS
    • jsforce
    • Salesforce Pub/Sub API
    • ECS Fargate
    • Redis

All work →

Now

At work I'm running two threads: a telephony voice-agent proof of concept on LiveKit and Twilio SIP, and the compliance layer under a document-upload feature — managed malware scanning, content moderation, and field-level encryption with KMS envelope keys. At Loxben, the Vendor Contract Analyzer is first out of the Finance Ops Hub.

Latest notes

The notes are where I write down what a decision cost and whether I'd make it again.

All notes →