Senior Platform Engineer

Department: Software Engineering

Location: San Francisco Office

Employment Type: FullTime

Why Flux

Flux is taking the hard out of hardware, by developing the first AI Hardware Engineer. Our goal is to democratize the ability to create bleeding edge hardware, and revolutionize how electronics are designed and built around the world.

About the Role

Flux is building the world’s first AI Hardware Engineer, and that means everything around it has to just work.

As a Senior Platform Engineer, you’ll own the full-stack systems that power Flux’s platform experience beyond the editor: billing, authentication, onboarding, and integrations.

You’ll ship production features that touch every user, keep the lights on, and make it possible for Flux to scale.

Responsibilities

• Build and maintain user-facing platform features (billing, auth, onboarding, settings).

• Integrate and maintain third-party APIs (Stripe, Firebase, analytics).

• Write TypeScript/Node backend services and React frontend components.

• Improve reliability and performance of core platform flows.

• Implement observability, logging, and error-tracking standards.

• Collaborate across teams to design APIs that support new products and integrations.

• Document architecture and best practices for your domain.

Required Qualifications

• 8+ years of professional software engineering experience.

• Strong proficiency in TypeScript, Node.js, and React.

• Experience integrating and maintaining 3rd party APIs.

• Proven track record shipping production full-stack web apps.

• Familiarity with cloud hosting (GCP/AWS/Firebase) and CI/CD basics.

• Strong debugging and cross-system troubleshooting skills.

• Excellent written and verbal communication; thrives in async, remote teams.

Preferred Qualifications

• Experience with multi-tenant SaaS or collaborative web platforms.

• Familiarity with auth frameworks (OAuth, JWT, Firebase Auth).

• Exposure to observability stacks (Sentry, Datadog, Grafana).

• Prior experience building internal tools or admin dashboards.

• Startup or 0 → 1 product-building experience.

Profile

Impact-oriented: You don't feel done until real people are getting real value from what you built.

Ambiguity-native: You thrive in the undefined. Agentic development is full of half-mapped terrain, soft constraints, and ideas that shift under your feet. That energizes you. You constantly update your intuitions as you go, and are excited to discover new and better ways to attack challenges we're still finding words to describe.

Collaborative: You share your thoughts early and often, and welcome debate and creative collaboration. Flux is a deeply collaborative company, and we believe that the best ideas can only win if they're said out loud.

Convention-averse: Flux is an AI-first company. We constantly experiment with new workflows, tools, and ways of working together. You feel an urgency to reimagine how we create and collaborate in this rapidly changing world, and you value critical thinking far above established conventions.

Ownership mentality: You are a self-starter, bias toward action, and care deeply about the team and community who lean on you and your work.