Sebastián Rosselot Moraga

Software Engineer · Platform / DevOps · Backend

Software engineer passionate about AI and everything related to cloud architecture. Specialized in backend and cloud platforms, with experience taking AI agents to production in a scalable and maintainable way, and designing secure systems.

Experience

  1. Platform Engineer · Racional

    May 2026 – Present

    Santiago, Chile

    • Designed and shipped to production the infrastructure for Racional Mind, an AI investment agent (Vertex AI), in isolated GCP projects with private networking. Serves 10,000+ users with zero infrastructure incidents.
    • Led Terraform adoption across 101 roots and 7 environments, defining the repository standard, keyless GitOps (WIF) on GitHub Actions, a project factory and observability as code.
    • Designed and implemented temporary, audited production access (JIT with GCP PAM and an internal CLI), reducing 292 standing permissions to 38 entitlements, aligned with Chile's data protection law (Law 21.719).
    • Designed and shipped to production the infrastructure for Racional Money (prepaid card) with CMEK, PITR, passwordless databases, WAF, an anti-exfiltration perimeter and HA egress at 1/60 of the managed option's cost.
    • Owned the regulatory KYC data remediation required by the custodian DriveWealth, correcting data for 56,000+ users ahead of the deadline with zero errors and full before-and-after verification.

    Racional is a Chilean fintech that makes investing more accessible, with stock investing, a prepaid card and an AI investment assistant.

    I designed and took to production the infrastructure behind Racional Mind, the company’s AI investment agent built on Vertex AI. When I took it over it was a single Cloud Run service. It now runs in dedicated GCP projects with fully private networking (Private Service Connect, internal load balancing and VPC peering), a VPC Service Controls perimeter and a highly available egress proxy.

    I led the company’s adoption of Terraform: the repository standard (reusable modules plus per-environment and per-service roots), a keyless GitOps pipeline on GitHub Actions with Workload Identity Federation and a project factory with organization-policy guardrails. I maintain it, along with the ongoing migration of our microservices.

    I started on the backend side, resolving production incidents in the investment pipeline (Pub/Sub, Firestore and Cloud Tasks) and building observability as code, with SLOs and burn-rate alerting.

    GCP · Terraform · Vertex AI · Cloud Run · VPC Service Controls · Privileged Access Manager · GitHub Actions · Pub/Sub · Firestore · Node.js · NestJS

  2. Software Engineer · diio

    Aug 2025 – May 2026

    Santiago, Chile

    • Built live recording of Google Meet, Zoom and Teams meetings end to end in the Chrome extension (2,000+ users), detecting voice activity, active speaker and participants by reverse engineering WebRTC and WebSocket.
    • Implemented streaming to AWS S3 (multipart upload) for 6+ hour sessions with sub-3-second confirmation, with idempotency, retries and a local IndexedDB queue (TypeScript, React).
    • Designed the Ruby on Rails ingestion backend with per-user authentication, integrity checks and pause and resume, removing the dependency on third-party recording bots such as Recall.ai.
    • Implemented WhatsApp group analysis in the extension by reverse engineering WhatsApp Web.

    diio is a Chilean AI startup that analyzes sales conversations (calls, meetings and chats) to help sales teams sell more and better.

    I built live meeting recording directly inside diio’s Chrome extension, with no third-party recording bots. That meant reverse engineering WebRTC and WebSocket traffic to detect voice activity, the active speaker and participants, and streaming recordings to AWS S3 through multipart upload.

    I also designed the Ruby on Rails ingestion backend, with retries driven by measured connectivity, plus an IndexedDB queue on the client so pending recordings are never lost.

    TypeScript · React · Chrome Extensions · WebRTC · Ruby on Rails · AWS S3 · IndexedDB

  3. Software Engineer Intern · SimplePark

    Apr 2025 – Aug 2025

    Santiago, Chile

    • Built REST endpoints on Cloud Functions (Node.js, TypeScript), automated their deployment with GitHub Actions and led the adoption of an AI-driven development methodology in a team of 6 engineers.
    • Built an integration with license-plate-recognition (LPR) cameras that captures photos to Google Drive and Cloud Storage at the same time, giving support a photo trail for one of the product's most common incident types.

    SimplePark builds a digital parking-meter platform, deployed during the municipal rollout in Las Condes.

    I built REST endpoints on Google Cloud Functions following Clean Architecture, backed by Firestore, automated deployments between staging and production, and kept the Swagger documentation in sync with GCP API Gateway.

    I led the team’s early adoption of AI-driven development with Cursor: shared guidelines and internal demos, cutting the time per feature from 5–7 hours to 15–45 minutes.

    GCP · Cloud Functions · Node.js · TypeScript · Firestore · GitHub Actions · Jest

  4. Teaching Assistant, Software Engineering Capstone · PUC Chile

    Mar 2025 – Jul 2025

    Santiago, Chile

    • Mentored a team of 12 students building a web app, a mobile app and the API behind them for a real client, Contandem.
    • Helped the team negotiate requirements with the client and reprioritize work based on the time available and the value delivered, tracking weekly progress.

    The Software Engineering Capstone at Pontificia Universidad Católica de Chile pairs student teams with a real client.

    Software Engineering · Technical Mentoring · Agile

  5. Full Stack Developer · ClassToPass

    Mar 2025 – May 2025

    Santiago, Chile

    • Built REST endpoints with Express and TypeScript (Sequelize, later Prisma) and responsive React views for an education startup.
    • Supported the migration from AWS EC2 to containers on ECS and ECR, working in a small team alongside the founders.

    ClassToPass is an education startup.

    Express · TypeScript · Prisma · React · AWS ECS · AWS ECR

Projects

Skills

Programming
TypeScript, JavaScript, Python, Ruby, SQL, HCL, Bash
Backend
Node.js, NestJS, Express, Ruby on Rails, REST, PostgreSQL, Redis, Prisma
Google Cloud
Cloud Run, Cloud Functions, Compute Engine, Vertex AI, Cloud SQL, Firestore, BigQuery, Cloud Storage, Pub/Sub, Cloud Tasks, VPC (Load Balancing, PSC, NAT, DNS), IAM and PAM, VPC Service Controls, Cloud Armor, KMS, Secret Manager, Cloud Build, Cloud Monitoring
AWS
EC2, ECS, ECR, S3, CloudFront, SES, API Gateway
DevOps and SRE
Terraform, GitHub Actions, Docker, CI/CD, GitOps, SLOs, Burn-rate alerting
Languages
Spanish (native), English (C1, FCE 98%)
Beyond code
Quinoa retail venture (2017), Private math tutor (2023–2025), Volunteer work (2016–2019), Powerlifting, Rugby, Water skiing, Padel

Education