Marcelo Sousa Ribeiro.

San Francisco, CA

My own venture: an agentic AI platform that connects LLMs to the business tools people already use (HubSpot, Salesforce, Gmail) and to third-party MCP servers, so agents can carry out real multi-step work. I set the product direction and built the platform end to end.

• Built the agent runtime connecting LLMs to 35+ business connectors and 100+ tools via LangChain, Composio, and third-party MCP servers.
• Multi-model routing across Claude, GPT, Gemini, and Llama via OpenRouter, with RAG over pgvector and Qdrant.
• Built and deployed Turnstile (open source) in front of the platform's agent traffic, cutting AI spend ~35% through per-session budgets and runaway-loop detection.
• Designed credit-based agent workflows for multi-step tasks: analyzing analytics and graphical data, preparing events, and drafting OKRs.

Remote

Deployed Canary's guest-journey products into major hotel chains' existing infrastructure — mobile room keys and the in-hotel digital compendium (upgrades, room service, amenities) — live across 4,000+ hotels.

• Partnered with Wyndham and IHG technical teams to deploy Apple Wallet / Google Wallet mobile room keys into their existing lock infrastructure, integrating Apple PassKit with the Vostio and Dormakaba lock SDKs.
• Owned the upgrades and room-service flows of the compendium across frontend and backend, including Stripe payments (Python, TypeScript).
• Built the tipping and feedback service, integrated with Google and TripAdvisor.

Remote

Worked directly with UK local-government stakeholders to deliver tenant, benefits, and payment systems for council housing — a regulated environment built to GOV.UK standards and accessibility requirements (Ruby on Rails, JavaScript, AWS).

• Led a team of 3; gathered requirements from council staff and turned them into council-management tools tenants and officers actually used.
• Built systems for benefits and payment collection from council homes.
• Brought UX and UI to GOV.UK accessibility standards, driving meaningful gains in tool adoption.
• Planned and executed deployment strategies that streamlined production releases and cut downtime.

Remote

Worked across 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 zero-downtime sharding of the monolithic PostgreSQL database — migrated to UUID keys and split it into 20+ shards across market areas (UK, EU, Emirates) to absorb major growth in traffic.
• Cut the top-10 slowest queries from ~5s to ~350ms average through denormalization and index improvements.

Remote

Led the payments team (4 engineers, 1 QA) and was a key developer in warehouse management and fulfillment for a subscription business that grew past 2 million subscribers (Ruby on Rails, JavaScript, TypeScript, Vue.js, AWS).

• Owned payments end to end for 1.5M active subscriptions — ~700K recurring charges per month across recurring and gift subscriptions, gift cards, and multiple recurrence models, integrated with Recurly.
• Built the assignment logic determining which products shipped for each subscription.
• Built warehouse-management and fulfillment features, integrating Pitney Bowes.

Remote

Led a team of 6 on a high-traffic marketplace for the game and hobby industry — 1,200+ online stores, ~2M orders/month, 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.
• Led a datacenter migration of 40+ servers/instances — DNS, PostgreSQL, MySQL, EC2, and S3.

Dublin, CA

Founded and ran a client-services software house, growing it to 15 engineers delivering Ruby on Rails APIs, JavaScript frontends (React, Angular, Ember.js), and native iOS and Android apps — owning each client engagement from the first conversation to launch.

• Ran end-to-end client engagements across industries: discovery, scoping, estimates and proposals, then delivery and post-launch support.
• Owned the client relationships — translating ambiguous business asks into roadmaps, negotiating scope changes, and being the technical point of contact for stakeholders.