Staff Software Engineer, AI Platform

Flex is a growth-stage, NYC-headquartered FinTech company hiring a Staff Software Engineer for the AI Platform team.

Responsibilities:

• Design agent platforms with orchestration and sandboxed runtimes
• Develop APIs and SDKs for safe agent onboarding
• Scale infrastructure across agent catalogs
• Improve operations through automation
• Mentor teams on responsible AI practices
• Create and manage agents and agent platforms, including multi-agent orchestration (LangGraph, custom planners, sub-agent patterns), tool/skill registries, and MCP-based integrations

Requirements:

• 6+ years experience
• Experience building AI-first workflows end-to-end
• LLM application design, prompt and context engineering, RAG, and human-in-the-loop patterns
• Experience creating and managing agents and agent platforms
• Multi-agent orchestration with LangGraph
• Tool/skill registries and MCP-based integrations

Tech stack: Python, Java, Golang, TypeScript/Node.js, AWS, Modal, E2B, Cloudflare Sandboxes, Daytona, Firecracker/gVisor runtimes

Location: Hybrid for NYC/SF/Salt Lake City; remote elsewhere in USA
Salary: Tier A (NYC/SF/Seattle): $200,000-$250,000