Senior Fullstack Software Engineer

About the Company

Stone is a technology and financial services company focused on the customer. We are the largest independent payment methods company in Brazil, aiming to transform the payment industry and serve Brazilian entrepreneurs.

Responsibilities

• Orchestrate agents and tools at scale, routing user intent between specialist agents and MCP tools while managing cost and latency.
• Implement real-time streaming and reliability using SSE, including turn reconciliation and watchdog mechanisms.
• Integrate AI deeply with platform flows such as approvals, deployment, and provisioning in a secure and auditable manner.
• Design UX for "citizen developers" to transform complex technical operations into simple, jargon-free experiences.
• Build robust backend services using Node/TS handling concurrency, Kafka events, Postgres, and memory management under load.

Requirements

• Solid experience as a Software Engineer
• Strong mastery of TypeScript and Node.js for backend
• Strong mastery of React and TypeScript for frontend
• Experience with distributed systems and asynchronous process orchestration
• Experience integrating with multiple services and APIs
• Ability to handle scale, concurrency, and reliability in critical systems (Kafka, Postgres, real-time streaming)
• Interest in building platform tools that abstract complexity

Preferred Qualifications

• Familiarity with Generative AI concepts
• Experience with conversational agents or MCP (Model Context Protocol)
• Collaborative mindset for working in multidisciplinary squads