Senior Software Engineer, Builder Studio

Apollo.io is hiring a Senior Software Engineer for Builder Studio, its product for building custom go-to-market software using natural language. The role owns major parts of the product end to end, including its user experience, AI agent, app runtime, integrations, security, and reliability.

Responsibilities:

• Build the core Studio experience: the chat-driven build loop, live preview, canvas, and the publish and share flow, so a non-technical user can go from an idea to a working tool in minutes
• Shape how the agent turns a natural-language goal into a plan, a set of pages, databases, and workflows, and then safely applies follow-up edits without breaking what already works
• Design the runtime and workflow layer for generated apps, including triggers, scheduled jobs, retries, logging, and the line between deterministic steps and agentic steps
• Own delegated identity, permissions, secrets, and isolation so generated apps act with exactly the access the user has, and nothing more
• Expand "connect once, use anywhere" integrations across Apollo data (contacts, companies, lists) and external systems like Google Sheets, Google Drive, CRMs, and MCP-based connectors
• Make the relationships between pages, data, workflows, and agents legible in the UI, so customers trust what their app is doing
• Work directly with design partners and customers, turn their feedback into shipped improvements quickly, and help define what the product becomes
• Raise the quality bar on a fast-moving 0 to 1 team: set patterns, write the tests and evals that matter, and own reliability, performance, and cost of what you ship

Requirements:

• 5+ years building and shipping production software, with real depth on both the frontend and backend of the same product
• Strong TypeScript and React skills, including complex, stateful UIs such as editors, canvases, builders, or real-time collaborative surfaces
• Solid backend and API design experience, ideally including event-driven or workflow systems where retries, idempotency, and observability matter
• Hands-on experience building with LLMs in production: agent loops, tool calling, context management, code generation, or evals. You know where models break and how to design around it
• Comfort making sound security calls on systems that run untrusted or generated code: sandboxing, delegated auth, scoped tokens, and secrets handling
• A track record of taking an ambiguous 0 to 1 product from rough prototype to something customers rely on, and making the scope-versus-quality calls that requires
• Product instinct and empathy for non-technical users. You care whether a RevOps lead can understand what their app is doing, not just whether the code is correct
• Genuine, current fluency with AI-assisted development and a high bar for quality and ownership
• Experience building low-code, no-code, or AI app-builder products, or developer tools
• Experience with edge or serverless runtimes such as Cloudflare Workers and Durable Objects
• Experience with Ruby on Rails at scale
• Background in GTM, sales, or marketing tech, or experience working closely with RevOps teams