Software Engineer, Security

Lassie; San Francisco (CA); On-site; USD 110,000 - 150,000; Full time

Job summary

Lassie, based in San Francisco, is looking for a Security Engineer to build and maintain security systems that protect customer data while enabling rapid development in critical office workflows.

The role involves collaborating closely with engineering teams on threat modeling and establishing strong data protection practices. Ideal candidates should have substantial experience in security systems development and be eager to contribute to a dynamic team.

Qualifications

• Experience in building core security systems.
• Familiarity with access control and data protection techniques.
• Strong understanding of threat modeling and incident readiness.

Responsibilities

• Build security systems for access control and audit logs.
• Collaborate with engineering to integrate security into workflows.
• Ensure trust and reliability in critical systems.

Skills

Security systems development

Data protection

Incident readiness

Threat modeling

Tools

Python

Postgres

TypeScript

Google Cloud Platform

Job description

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.