Sr. Staff Software Engineer, Pinterest Assistant

Working closely with Product, Design, Frontend, Infrastructure, and Machine Learning teams, you’ll shape the long-term technical strategy, raise the engineering bar across the organization, and build reliable, high-quality experiences that delight millions of Pinners.

What you’ll do:

• Define and drive the technical vision and architecture for the backend systems powering Pinterest Assistant, ensuring they scale reliably as the product reaches millions of users.
• Lead the design and implementation of the core Assistant platform including orchestration, memory and personalization, context management, APIs, tool integrations, and backend infrastructure.
• Drive technical strategy, identifying foundational platform investments that unlock new Assistant capabilities while improving developer velocity, reliability, and scalability.
• Partner closely with Product, Design, Frontend engineers, ML engineers, and Infrastructure teams to build a deeply personalized, multimodal conversational experience.
• Shape the architecture for AI-powered applications, including retrieval, context assembly, tool execution, memory, and model orchestration, in partnership with ML teams.
• Establish engineering best practices for production LLM and agent systems, including observability, logging, evals, safety mechanisms, rollout strategies, and incident response.
• Mentor engineers, raising the technical bar through architecture reviews, technical guidance, and thoughtful engineering leadership.
• Navigate ambiguity and make pragmatic architectural decisions that balance rapid product iteration with long-term maintainability.
• Influence technical direction beyond the immediate team by collaborating across teams and helping shape Pinterest’s broader AI platform strategy.
• Stay current with advances in LLMs, agentic systems, and backend platform design, and apply them pragmatically to consumer product development.

What we're looking for:

• Bachelor’s degree in a relevant field such as computer science or equivalent experience
• 10+ years of backend software engineering experience, including significant experience leading large, ambiguous systems that power consumer experience as a senior IC.
• 3+ years operating as a technical lead, driving the architecture and development of large-scale distributed backend systems.
• Strong backend engineering experience in Python, TypeScript, Node or similar languages and ecosystems.
• Experience building platforms or foundational infrastructure that enables product teams to move faster.
• Strong understanding of modern model-driven systems and experience partnering closely with machine learning engineers on AI-powered products.
• Strong leadership, communication, and cross-functional collaboration skills
• Familiarity with concepts such as retrieval, ranking, personalization, inference, context management, or orchestration, with ability to collaborate effectively on technical design.
• Track record of mentoring senior engineers and elevating engineering quality across an organization
• Product-minded and execution-oriented, with the ability to lead in ambiguity and move fluidly between strategy and hands-on implementation
• A strong builder’s mindset: you know how to create momentum in ambiguous spaces, make pragmatic early decisions, and lay the technical foundation for systems that will grow in scale, complexity, and impact over time.
• Nice to have:
• Experience building AI-powered or LLM-based products at scale
• Experience designing systems for conversational AI, agents, tool calling, or multimodal experiences.
• Experience with retrieval, ranking, recommendation, search, or personalization systems.
• Familiarity with embeddings, retrieval-augmented generation (RAG), context management, or memory architecture.
• Experience partnering with Applied Scientists or Machine Learning engineers to bring ML capabilities into production.
• Familiarity with evaluation frameworks, experimentation, and quality frameworks for AI products.
• Full-stack development experience

Relocation Statement: Insert whether this job is eligible for relocation assistance.

• This position is not eligible for relocation assistance. Visit our PinFlex page to learn more about our working model.