Senior Backend Engineer

Why Weave Exists

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.

The Role & Your Mission

We're looking for a Senior Backend Engineer, reporting directly to the Backend Engineering Manager, that can navigate between data, AI, and backend systems. Stability, performance, and reliability of the AI system are the core responsibilities. You will be asked to develop novel solutions to customer problems, characterize the results, and deliver the solutions into production. You'll be successful in this role if you can go from idea, to experiment, to testing, to production without getting lost or stuck at one of the steps. We care more about solving problems than using the latest buzz. We prefer simple, well-tested, stable solutions that are dependable, yet impressive.

What You'll Own

• Understanding customer problems and translating that into simple solutions
• Working with Product and Design to quickly find solutions
• Writing performant, simple code. We run Django + Python + Postgres + Redis.
• Managing ongoing conceptual and technical complexity while delivering value on Product projects
• Integrating and optimizing LLM APIs (OpenAI, Anthropic) for document processing and AI features

What You'll Bring

• 5+ years of Django in production with strong fundamentals in database optimization, caching, and system design
• Hands-on LLM experience — you've integrated OpenAI/Anthropic APIs directly, understand prompt engineering, and can debug model behavior
• SAAS product experience on highly scalable products
• Strong knowledge and experience with AWS deployment practices and concepts
• Product-focused mindset — you balance speed and quality, make pragmatic trade-offs, and ship solutions that solve customer problems
• Production ownership — comfortable with on-call, debugging live issues, and taking responsibility for the systems you build
• Low ego, high output — collaborative, adaptable, and focused on team success over individual heroics
• Bonus: Early-stage startup experience, regulated domain experience (healthcare/pharma), or real-time collaborative systems

What We Offer

• Competitive salary ($175,000 - $225,000) and equity packages
• Comprehensive health, dental and vision insurance
• Generous PTO, parental leave, OneMedical, TalkSpace, Teladoc
• Career development opportunities within a company entering a growth phase
• Hybrid in San Francisco with in-office days Tues/Wed/Thurs and flexibility to work remote Mon/Fri