Senior Product Engineer (AI)

About the role

Plain is redefining B2B customer support with a fast, scalable platform that leverages AI to move beyond reactive help. As a Senior Product Engineer you will own the infrastructure that enables rapid, safe AI feature delivery and help shape a category‑defining product.

Key responsibilities

• Own and ship AI features such as agents, assistants, insights—from concept to production.
• Design and implement backend services for AI integrations and data pipelines.
• Build robust APIs and abstractions for internal AI usage.
• Drive system scalability through caching, optimization, and processing patterns.
• Develop and evolve AI infrastructure, including architecture, evaluation, and iteration pipelines.
• Address complex AI challenges around accuracy, reliability, and quality using quantitative methods.
• Advocate externally by writing, speaking, and engaging with the AI community.

Required profile

• Experienced backend engineer who has shipped AI products in the OpenAI/Anthropic era, especially text‑ and data‑heavy applications.
• Hands‑on experience with LLM orchestration and LLM API optimization (cost, latency).
• Familiarity with Retrieval‑Augmented Generation (RAG) architectures and technologies.
• Experience with AI observability to measure real impact.
• Product‑minded, customer‑focused, self‑driven and comfortable in a fast‑moving startup.

Required skills

• LLM orchestration
• LLM API optimization
• RAG architectures
• AI observability
• PostgreSQL