Founding Engineer

Open Systems Technologies; New York (NY); On-site; USD 180,000 - 250,000; Full time

Benefits offered by this job

Equity

Onsite work

Job summary

Open Systems Technologies is seeking a Founding Engineer in New York City to own a full product area from day one, shaping ideas into production with direct access to customers and no PM between you and the customer. You will drive product decisions, ship fast, and have potential leadership opportunities as the company scales.

You’ll build full-stack features in TypeScript and work on agent-based products using LL M APIs and SDKs, including voice/SMS agents, memory, and guardrails.

Qualifications

• Shipped a 0 to 1 product at a high-growth startup or new product team.
• Comfortable making product decisions and talking to customers.
• 3–10 years of full-stack engineering experience.
• Deep experience in at least one area: voice/SMS agents, long-running state/memory, B2B2C or marketplace products, or agent evals and guardrails.
• Built real products directly on LL M APIs or agent SDKs (Anthropic, OpenAI, Vercel AI SDK, Mastra) not tutorials.

Responsibilities

• Build and ship full-stack features in TypeScript (Node.js, React/Next.js).
• Build agent products on LL M APIs and agent SDKs.
• Work on voice and SMS agents, memory, evals and guardrails.
• Talk to customers and turn needs into product decisions without a roadmap.

Skills

TypeScript

Node.js

React/Next.js

Customer communication

Product decisions

Full stack engineering

Tools

Anthropic

OpenAI

Vercel AI SDK

Mastra

Job description

An AI startup in New York City is looking for a Founding Engineer to join their team.

Compensation: $180K–$250K + Equity

Location: New York, NY; 5 days onsite per week

Within this role, you'll own a full product area from day one, from the first idea through production, with no PM between you and the customer. You'll get on customer calls, make product decisions yourself, and ship fast. As the company grows, you can move into leadership or stay deep on the IC track.

Responsibilities:

• Build and ship full stack features in TypeScript (Node.js, React/Next.js)
• Build agent products directly on LLM APIs and agent SDKs
• Work on voice and SMS agents, long-running agent state and memory, and evals and guardrails
• Talk to customers and turn what they need into product decisions without waiting for a roadmap

Qualifications:

Required

• Shipped a 0 to 1 product at a high-growth startup, as a founder, or on a new product team at a big tech company
• Strong TypeScript (Node.js, React/Next.js)
• Comfortable making product calls on your own and talking to customers
• 3 to 10 years of full stack engineering experience
• Deep experience in at least one of these: production voice or SMS agents (Retell, Vapi, Ultravox, 11x-style), long-running agent state and memory, B2B2C or marketplace products, or agent evals and guardrails
• Has built real products directly on LLM APIs or agent SDKs (Anthropic, OpenAI, Vercel AI SDK, Mastra or similar), not tutorials or thin wrappers

Preferred

• Former YC founder or a founder whose company got real traction (revenue, funding or an acquisition); If it failed, you can explain why
• Top CS program, which matters most for candidates with 3 to 4 years of experience
• Python for real-time voice pipelines (LiveKit, Deepgram, STT/TTS) or eval tooling (Braintrust, LLM-as-judge)