Frontend Engineer San Francisco Bay Area, CA

At Weave, our mission is to evolve how therapeutic knowledge is captured, transformed, and communicated throughout drug development. We do this by equipping human experts with AI instruments to enable drugs to be brought to patients as rapidly, safely, and inexpensively as possible.

The Weave Platform streamlines regulatory workflows from start to finish by intelligently, creatively, and effectively infusing every step with AI. Together with our customers, Weave is designing and building the AI workbench for the entire therapeutic lifecycle.

We're looking for a Staff Frontend Engineer to own the technical direction of our frontend platform. This is a high‑leverage role: you'll define the architecture, set engineering standards, and build the foundational systems that the rest of the engineering team ships on top of. You'll split your time between hands‑on technical work, cross‑team collaboration, and raising the bar for how we build software.

You’ll identify the highest‑impact technical problems, drive alignment on solutions, and ensure we’re making architectural decisions that scale. We prefer simple, well‑tested, stable systems that are dependable and fast. We care more about solving the right problems well than chasing the latest framework.

• Define and evolve the frontend architecture for our platform, making decisions that balance velocity today with maintainability at scale
• Establish engineering standards, patterns, and best practices across the frontend codebase
• Drive technical strategy and roadmap for frontend infrastructure, architecture, tooling, and developer experience
• Be the technical decision‑maker on high‑stakes, ambiguous problems and document the "why" behind those decisions

• Design and build the core systems that product engineers depend on: component libraries, shared abstractions, performance infrastructure, and testing frameworks
• Own the architecture of our document editor experience, including real‑time multi‑player collaboration, conflict resolution, and extensibility
• Improve frontend build, deployment, and observability tooling to keep the team fast and confident

• Partner with Product, Design, and backend engineering to shape technical approaches to complex product problems
• Mentor and elevate other engineers through code review, pairing, architectural guidance, and thoughtful feedback
• Participate in hiring and help build a high‑caliber frontend engineering team

• 10+ years of professional software engineering experience, with deep expertise in Type Script, React, and the modern web platform
• You've designed and built frontend systems at scale and you understand the tradeoffs between different state management approaches, rendering strategies, and API patterns at a gut level
• Experience building complex, interactive applications (rich text editors, real‑time collaboration, or similarly stateful UIs strongly preferred)

• You're an expert at integrating AI‑powered development tools (Cursor, Claude, etc.) into your workflow to move faster and produce higher‑quality code
• You know how to leverage AI for code generation, exploration, debugging, and documentation while applying the deep technical judgment needed to evaluate, refine, and take full ownership of everything you ship. We’re looking for engineers who treat AI as a force multiplier for their craft, not a substitute for it.
• You have opinions on where AI tooling genuinely helps (and where it doesn’t), and you’re excited to help the team adopt these tools effectively

• You've operated at a Staff+ level (or equivalent scope) at a high‑growth startup or technology company, ideally at an early‑stage company (