Senior Founding Engineer Jobs (NOW HIRING)

Senior Founding Engineer | San Francisco, CA | Avg $200K–$250K

Role Overview

A rapidly scaling AI technology company is seeking a Senior Founding Engineer to help architect and scale the infrastructure powering conversational AI evaluation, observability, and simulation systems handling millions of calls per month.

This is a highly technical, architecture-heavy role focused on building resilient, scalable systems across the full stack. The company is looking for engineers who move quickly, think deeply about systems design, and care about building high-performance infrastructure that operates reliably at production scale.

This role is ideal for experienced engineers who thrive in fast-moving startup environments, enjoy solving complex systems problems, and want direct influence over product architecture and engineering culture.

About the Company

The company builds simulation, evaluation, and observability systems for conversational AI agents across voice and multimodal experiences. Founded by former AI engineers from Microsoft and AWS, the platform helps organizations validate and improve AI agent performance before deployment into real-world environments.

Backed by Y Combinator, Floodgate, and PeakXV, the company has experienced rapid growth and now supports millions of AI-powered conversations per month for enterprise customers including major technology and Fortune 500 organizations.

Key Responsibilities

Systems Architecture & Scalability

Architect and develop scalable systems supporting conversational AI evaluation and simulation

Design resilient infrastructure capable of handling millions of real-time interactions

Optimize backend systems, database performance, and frontend responsiveness

Reduce system bottlenecks across distributed services and infrastructure layers

Design systems prioritizing reliability, scalability, and operational efficiency

Full-Stack Engineering

Build and maintain frontend and backend systems across the platform

Develop APIs, real-time systems, and infrastructure services

Improve frontend dashboard performance and user experience

Support CI/CD pipelines and production deployment systems

Contribute to architectural decisions and technical direction

AI & Conversational Systems

Develop pipelines and systems that analyze conversational AI performance

Detect system failures, performance issues, and reliability gaps

Support voice AI and multimodal infrastructure initiatives

Build observability and evaluation tooling for AI agents

Work directly with customers on implementation and deployment efforts

Engineering Leadership & Standards

Establish strong engineering practices around architecture, code review, and system quality

Support scalable engineering workflows within a fast-growing environment

Collaborate directly with founders and leadership teams

Contribute to technical strategy and long-term infrastructure planning

Requirements

Minimum 6 years of full-stack engineering experience

Deep proficiency in:

- TypeScript

- Python

- SQL

- AWS

Strong systems architecture and scalability experience

Experience building and optimizing large-scale production systems

Strong communication and collaboration skills

Comfortable working onsite within fast-paced startup environments

Ability to move quickly while maintaining engineering quality standards

Tech Stack

Frontend:

React

Tailwind

TypeScript

NextJS

Backend:

Python

FastAPI

Supabase

Redis

AWS (Lambda, EC2, WebSockets, SIP)

Voice AI & Infrastructure:

LiveKit

Deepgram

Cartesia

ElevenLabs

Gemini

CI/CD pipelines

Preferred Qualifications

Founding engineer or YC startup experience

Voice AI or conversational AI systems experience

Experience building polished frontend products

Technical founder or VC-backed startup background

Experience within high-performance AI engineering environments

Strong ownership mentality and systems thinking

Compensation & Benefits

Avg Base Salary: $200,000–$250,000

Health Insurance

Gym Membership Reimbursement

$500 Workspace Setup Stipend

High ownership and direct impact opportunity

Fast-moving engineering culture with strong growth trajectory

Interview Process

Intro Call with Founder

Take-Home Assignment

Technical Interview

Onsite Work Trial

Final Offer

Work Environment

Onsite in San Francisco, CA

Collaborative startup environment

Direct access to founders and leadership

High-growth AI infrastructure company

Expanding engineering organization

Ideal Candidate

Highly technical full-stack engineer with strong architecture depth

Comfortable operating in high-scale production environments

Strong systems thinker and problem solver

Fast-moving, execution-oriented engineer

Low ego with strong communication skills

Passionate about mastering technical and personal challenges

Excited about building infrastructure powering the future of conversational AI