Senior Software Engineer, Fullstack (Builder Studio)

Responsibilities

Own major parts of Builder Studio, including its chat-driven app-building experience, live preview, publishing flows, and the runtime and workflows that execute generated apps. Build secure permissions and integrations, improve reliability and usability with customer feedback, and establish quality practices for the product.

Requirements

Candidates need at least five years of production software experience with strong TypeScript and React skills, backend and API design experience, and hands-on experience building LLM-powered systems. They should also have experience taking ambiguous products from prototype to customer-ready scale, sound security judgment for generated code, and strong product instincts for non-technical users.

Skills

• TypeScript
• React
• Ruby On Rails
• Node.js
• LLM Agents
• API Design
• Frontend Development
• Backend Development
• Workflow Systems
• Event-Driven Systems
• Code Generation
• Sandboxing
• Delegated Authentication
• Cloudflare Workers
• Durable Objects
• Product Development

Benefits

• Equity
• Company Bonus
• Paid Holidays
• Flexible Paid Time Off
• Parental Leave
• Employee Assistance Program
• Wellbeing Benefits
• Global Travel Coverage
• Life Insurance
• Disability Insurance
• Health Insurance
• Dental Insurance
• Vision Insurance

About this role

Apollo.io is the leading go-to-market solution for revenue teams, trusted by over 500,000 companies and millions of users globally, from rapidly growing startups to some of the world's largest enterprises. Founded in 2015, the company is one of the fastest growing companies in SaaS, raising approximately $250 million to date and valued at $1.6 billion. Apollo.io provides sales and marketing teams with easy access to verified contact data for over 210 million B2B contacts and 35 million companies worldwide, along with tools to engage and convert these contacts in one unified platform. By helping revenue professionals find the most accurate contact information and automating the outreach process, Apollo.io turns prospects into customers. Apollo raised a series D in 2023 and is backed by top-tier investors, including Sequoia Capital, Bain Capital Ventures, and more, and counts the former President and COO of Hubspot, JD Sherman, among its board members.
About Apollo
Apollo is the AI-powered go-to-market platform that helps revenue teams find, engage, and convert their best customers. We combine a database of more than 210 million contacts and 35 million companies with an agentic end-to-end GTM platform, and more than 500,000 companies rely on us to run their go-to-market motion. We are profitable, growing fast, and rebuilding the product around AI and agents.
About Builder Studio
Builder Studio is Apollo's new product for building custom GTM software in plain English. A RevOps lead, GTM engineer, or founder describes the tool they need, and Builder Studio plans it, generates real code, and turns it into a working app they can preview, refine through conversation, publish, and share with their team.
Every app is made of four building blocks: Pages for the interface, Databases for structured records, Workflows for visible backend logic and scheduled jobs, and Agents that reason over Apollo context and take action. What makes it different from a generic app builder is that Apollo's data, enrichment, sequences, deliverability, and CRM sync are native building blocks, not bolted-on third-party integrations.
It is one of Apollo's flagship AI bets. The product is in the hands of early design partners now and is heading toward broad launch, which means the next year is about taking a working product and making it reliable, secure, and loved at scale.
Your role and mission
You will own major slices of Builder Studio end to end, across the builder experience customers see and the systems that make generated apps actually run. You will work on problems most engineers have never touched: an agent that writes and edits software on a customer's behalf, a runtime that safely executes that code with the user's own Apollo permissions, and an interface that makes all of it understandable to someone who has never read a line of code.
What you will do
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
How we work: AI-native by default
You treat AI-assisted development as a core part of how you work. You use agents to move faster on design, investigation, and implementation, with clear judgment about where to review closely, and you look for ways AI raises the leverage of the whole team. On Builder Studio this is doubly true: you are building an AI that writes software, so your own instincts for where AI-generated code succeeds and fails directly shape the product.
What we are looking for
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
Nice to have
Experience building low-code, no-code, or AI app-builder products, or developer tools
Experience with edge or serverless runtimes such as Cloudflare Wo...

About Apollo.io

Software Development · 501-1,000 employees · headquartered in San Francisco, California