Marcelo Sousa Ribeiro

Founding engineer at FlooxAI — "vibeworking for everyone": a Claude Code–style AI agent connected to the tools people already use (HubSpot, Salesforce, Gmail) plus third-party MCP servers and connectors, so anyone can buy credits and put an agent to work on real tasks.

• Build the agentic core that connects LLMs to business tools and connectors — HubSpot, Salesforce, Gmail, and third-party MCP servers — via LangChain and Composio.
• Ship credit-based workflows that get real work done: buying tickets, booking hotels, preparing events, analyzing analytics and graphical data, and drafting OKRs.
• Wire multi-model LLM access through OpenRouter with vector-database retrieval and agentic orchestration.
• Bring a full-stack and mobile engineering background to ship these AI features end to end.

One of the lead developers on the guest journey — built a significant part of the compendium (the in-hotel digital booklet for amenities, room service, and upgrades) across frontend and backend, with tools deployed to tens of thousands of hotels.

• Built a significant part of the compendium — the in-hotel digital booklet for amenities, room service, and upgrades — across frontend and backend (Stripe, Python, TypeScript).
• Built and launched Apple Wallet / Google Wallet mobile keys for hotels, integrating Apple PassKit, Vostio, and Dormakaba SDKs.
• Built the tipping and feedback service, integrated with Google and TripAdvisor.
• Shipped guest-journey tools deployed to tens of thousands of hotels.

Lead full stack engineer building tools for UK local governments to manage council homes, tenants, and tenant–council communication — including systems for benefits and payment collections from council homes — built to GOV.UK standards and accessibility requirements (Ruby on Rails, JavaScript, AWS).

• Led a team of 3 to build and optimize council-management tools, increasing tenant satisfaction by 80%.
• Built systems for benefits and payment collections from council homes.
• Improved UX and UI to GOV.UK standards and accessibility requirements, increasing tool adoption by 60%.
• Planned and executed deployment strategies that streamlined production releases and cut downtime.

Senior full stack engineer working across all areas of the platform for the UK's leading food-delivery service — focused on database performance and a large-scale, multi-market sharding effort (Ruby on Rails, PostgreSQL, AWS).

• Drove the data-sharding effort — converted a huge monolithic database to UUID keys and split it across market areas (UK, EU, Emirates), boosting server efficiency by 140%.
• Designed a migration strategy that accommodated a 200% increase in user traffic, breaking a monolithic database into 20+ more performant shards.
• Optimized hard, heavy queries through data denormalization and index improvements, improving load times by 60%.
• Worked across all areas of the platform, backend and frontend.

Owned payments end to end and was a key developer in warehouse management and fulfillment — supporting a subscription business that grew past 2 million subscribers (Ruby on Rails, JavaScript, TypeScript, Vue.js, AWS).

• Owned the payments system end to end — recurring subscriptions, gift subscriptions, gift cards, and multiple recurrence models (monthly, bi-yearly, yearly, one-time), integrated with Recurly.
• Built the assignment logic that determined which products shipped based on the subscription chosen.
• Supported a subscriber base that grew past 2 million at peak.
• Developed backend payment endpoints that improved transaction accuracy by 80%, and optimized checkout to cut checkout times by 60%.
• Contributed to warehouse management and fulfillment, integrating Pitney Bowes.

Lead software engineer (team of 6) on a high-traffic marketplace platform for the game and hobby industry — 1,200+ online stores, 2M orders/month, and 5M monthly active users.

• Built an Elasticsearch cluster with geocode search over hundreds of millions of records, cutting unified search from 20+ seconds to ~1 second.
• Added frontend caching and a JSON layer to keep the heavy-traffic platform fast.
• Led the team through a datacenter migration of 40+ servers/instances — DNS, PostgreSQL, MySQL, EC2, and S3.
• Ran the platform at scale: 1,200+ online stores, 2M orders/month, and 5M monthly active users.