Owned the architecture and migration of a multi-tenant user and permissions platform supporting 100,000+ users across 10,000 organizations. Designed the users_roles Django module and User Management API v2.0, including schemas, indexes, roles, permissions, and organization-level ownership. Authored the migration RFC and staged production rollout using checksum-based integrity validation, rollback mechanisms, and compatibility flags. Evaluated service boundaries and consolidated distributed permission logic into a modular monolith, reducing unnecessary service-to-service communication and operational complexity.

Built customer-facing booking and payment workflows across backend services and real-time product experiences using Python, TypeScript/JavaScript, React, RabbitMQ, WebSockets, Stripe, and external REST APIs. Owned the end-to-end booking path from WhatsApp inquiry and availability checks through Stripe payment, webhook processing, reservation confirmation, and guest notification. Built asynchronous event-driven workflows with RabbitMQ and webhooks, including controlled retry, recovery, and human-handoff paths. Contributed to real-time React/TypeScript product experiences using WebSockets and integrated backend workflows with customer-facing interfaces.

Hands-on technical lead for Fondeadora Negocios, a B2B fintech product spanning backend services, financial integrations, AWS infrastructure, deployment pipelines, data workflows, and a Next.js customer-facing application. Coordinated technical decisions across a six-engineer team while remaining an active IC. Designed backend architecture for payments, transfers, and SPEI integrations using Python services, REST/webhook interfaces, asynchronous queues, and idempotent financial workflows. Defined serverless AWS infrastructure across Lambda, SQS, dead-letter queues, IAM, CloudWatch, and service-level resource boundaries; also worked with ECS-based production services. Designed CI/CD pipelines for backend services and the Next.js frontend using GitHub Actions, standardizing build and deployment workflows across Fondeadora Negocios. Built batch payment workflows allowing business customers to upload CSV files containing thousands of transactions for validation and asynchronous execution. Built PostgreSQL reporting and reconciliation workflows supporting transaction analysis and financial month-end operations.

Designed and operated financial systems processing ~500,000 transactions per day using AWS Lambda, SQS, Step Functions, and event-driven workflows. Built public-facing webhook processing for card-payment and SPEI events, validating provider data and routing transactions into downstream financial workflows. Designed stateful workflows for transfers, refunds, retries, and compensation paths and implemented idempotency to prevent duplicate transaction processing. Participated in production operations and incident response for regulated payment systems, using CloudWatch, Sentry, and PagerDuty.