Founding Engineer Full Time

Founding Engineer

NYC | In office | Full-time

The B2B information services market is $120B. From sales intelligence providers to Bloomberg terminals. All of it locked behind massive annual contracts, stale databases, and clunky UIs built for humans clicking buttons.

Agents don’t click buttons. Agents call APIs.

We’re building just-in-time, pay-as-you-go data access for agents. No annual contracts. No stale data. No seat licenses. Agents query what they need, when they need it, and pay only for what they use.

We’re democratizing the data that makes it possible to run high-impact B2B businesses. A two-person startup gets the same data access as a Fortune 50.

That’s the opportunity. You’d help us build it.

What Deepline does

Deepline is a CLI and API for B2B data providers. Contact discovery and enrichment across 44+ providers from one command. Developers install it in 30 seconds and start getting revenue-driving data immediately.

We’re PLG and developer-native. No sales demos required. Engineers find us, install the CLI, and start using it. Your job is to make that experience fast, reliable, and delightful.

What you’ll build

CLI and SDK

The deepline CLI is how developers interact with us. You’ll own the install flow, authentication, command structure, and error handling. Python core with TypeScript for the web layer.

AI agent tooling

Developers use Deepline from Claude Code, Cursor, and other AI coding tools. You’ll build the skill docs, MCP integration, and tool interfaces that make AI agents effective at GTM workflows. How do we provide the right data for the right query at the right time for the right price?

Deterministic data engine

Our core value prop: we guarantee the best data point at the best price. Try Provider A, if no result try Provider B, stop when you get a hit. Sounds simple. In practice: rate limits, credential rotation, partial results, provider-specific validation, cost optimization. You’ll make it reliable.

Provider integrations and network effects

We connect to 80+ B2B tools and data providers. Each integration has its own quirks. You’ll build the system to manage providers, maintain existing ones, and handle the edge cases that make this reliable. With the data we see around queries and outcomes, how do we improve the experience across the entire system?

Tech stack

• Languages: TypeScript, Python, Node.js
• Frontend: Next.js, React, Tailwind CSS
• Runtime: Bun, Node.js
• Database: Convex, Neon (PostgreSQL), Redis
• Infrastructure: Vercel, Railway, AWS
• APIs: REST, GraphQL, 44+ third-party provider integrations
• AI/ML: Claude API, OpenAI API, MCP protocol, LLM tool use, agentic workflows

You’ll recognize yourself here

• You’ve built developer tools. CLIs, SDKs, APIs. You know what makes a good DX.
• You write TypeScript and Python. Strong typing matters to you.
• You’ve dealt with third-party API integration pain. Rate limits, auth flows, inconsistent schemas, flaky endpoints. You know how to make unreliable things reliable.
• You care about the details. Error messages, install scripts, docs. The stuff that makes developers trust a tool.
• You want to work on something developers actually use. Not internal tooling. Not dashboards. Tools that ship to real users every day.
• You’re comfortable with ambiguity. Early stage means figuring things out as you go.

What the first 90 days look like

Month 1

You ship your first provider integration. You fix bugs in the CLI that users reported on Discord. You improve an error message that was confusing. You understand how the waterfall engine works.

Month 2

You own a chunk of the codebase. Maybe the credential management system. Maybe the MCP integration. You’re shipping features that users request. You’re in the Discord helping developers debug their workflows.

Month 3

You build ways for agents to navigate a skill graph and ship an agentic optimization framework. Agents today pick tools linearly. You build the infrastructure that lets them reason about which skills to compose, when to backtrack, and how to optimize multi-step workflows automatically. This becomes core to how Deepline works.

Team

Small senior team from Uber, Lyft, OM1, Capchase. MIT, Waterloo, Berkeley, Princeton, UCSD. You’ll be engineer #5-6. Direct collaboration with founders and users.

$3.3M pre-seed from Lerer Hippeau, K5 Global, Exceptional Capital.

Compensation

• Salary: 140K-220K
• Equity: Meaningful early-stage equity (0.5-1.5%)
• Benefits: Health insurance, dental, vision, equipment budget
• Location: NYC, in-person (Manhattan)

Keywords: Software Engineer, Full Stack Engineer, Backend Engineer, Developer Tools, CLI Development, SDK Development, API Development, Python Developer, TypeScript Developer, Node.js, React, Next.js, PostgreSQL, Redis, AWS, Startup, Early Stage, Series Seed, B2B SaaS, AI Infrastructure, LLM, Machine Learning, Data Engineering, API Integration, Developer Experience, Platform Engineering