Senior AI Systems Architect – Full-Stack

Mosaic.tech; San Francisco (CA); On-site; USD 240,000 - 320,000; Full time

Benefits offered by this job

Competitive salary

Equity

Ownership in a fast-scaling AI company

Close collaboration with founders

Job summary

AdsGency AI seeks a Senior Member of Technical Staff to design and scale AI-driven infrastructure for multi-agent ad automation. You’ll work with founders and senior engineers on real-time pipelines, LLM orchestration layers, and a stack that spans Python, FastAPI, and React/Next.js.

You’ll lead architecture decisions, mentor junior engineers, and shape the platform as it grows from startup to global scale. A strong backend focus with distributed systems expertise is essential.

Qualifications

• 5+ years of software engineering or systems design.
• Experience in early-stage startups or as a founding engineer.
• Builder mindset with fast iteration and ownership.
• Strong backend engineering proficiency (Python, FastAPI).
• Deep knowledge of distributed systems and service orchestration.
• Ability to design from first principles and shape frameworks.
• Experience with scalable infra (microservices, event-driven, or serverless).

Responsibilities

• Architect and scale AI-driven infrastructure for multi-agent ad automation.
• Design real-time data pipelines and LLM orchestration layers.
• Lead design reviews, set technical direction, mentor engineers.
• Develop APIs and microservices powering campaigns and analytics.
• Contribute to React/Next.js UIs for dashboards and collaboration.

Skills

Backend engineering

Distributed systems

System design

First principles

Ownership

Builder mindset

Startup experience

LLM / multi-agent

Tools

Python

FastAPI

PostgreSQL

Redis

Go

Kafka

Docker

AWS

GCP

PGVector

Job description

AdsGency AI seeks a Senior Member of Technical Staff to design and scale AI-driven infrastructure for multi-agent ad automation. You’ll work with founders and senior engineers on real-time pipelines, LLM orchestration layers, and a stack that spans Python, FastAPI, and React/Next.js.

You’ll lead architecture decisions, mentor junior engineers, and shape the platform as it grows from startup to global scale. A strong backend focus with distributed systems expertise is essential.