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Software Is Eating the World

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Lassie

a16z portfolio company

Software Engineer, Security

Location
San Francisco, California, USA
Job type
Full-time

About the role

Posted Jun 3, 2026

Our mission is to help small businesses run themselves. We’re starting with doctors’ offices, building autonomous systems that handle busywork and complete the workflows that keep the office moving every day. Our team is small, flat, and ambitious. We value craft, intellectual rigor, and direct communication.

About the role

Security engineers make Lassie trustworthy enough to operate inside critical office workflows. You’ll build the controls, systems, and engineering practices that protect customer data while letting an ambitious team move quickly.

What you'll do

  • Build core security systems across access control, audit logs, data protection, monitoring, and incident readiness

  • Partner with engineering to threat-model new agent workflows and make security part of how we build

  • Help Lassie move quickly while earning the trust required to operate inside critical office systems

Some things we've built

  • Data pipelines processing $1B+ in insurance claims

  • Systems that eliminate thousands of hours of paperwork every month

  • A sync engine backed by encrypted SQLite in the browser, enabling 100ms experiences for healthcare payments and patient ledgers

Technology we use

We invest heavily in productivity. Engineers should have the best tools for the job and the freedom to choose them.

  • Python (Django, Pydantic AI), Postgres, Redis

  • TypeScript, React, Tailwind

  • Google Cloud Platform, Vercel

  • Linear, Slack, Notion

Joining us

To start, you'll have a handful of conversations with our team and founders. If there is mutual excitement, we'll invite you to the office where you'll work on a small project and meet the team.

Explore what’s next at Lassie.

Apply for this role

At a glance

Location
San Francisco, CA · San Francisco, California, USA
Employment
Full-time
Team
Engineering
Apply for this role

You’ll be taken to Lassie to apply.

The company

Lassie

Lassie

Lassie helps small businesses run themselves. Starting with doctors' offices, building AI agents that handle busywork and complete the workflows that keep practices moving every day.

Series A11–50 employeesConsumerAIFintech
More roles at Lassie

Explore what’s next at Lassie.

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