Product Engineer, Backend (Rust)

We're looking for a Product Engineer, Backend (Rust) to join White Circle, an AI Safety company building the policy enforcement and optimization layer for AI systems. Backed by $11M from senior leaders at OpenAI, Anthropic, HuggingFace, Mistral, and DeepMind, White Circle processes 100M+ API calls monthly and runs its own LLMs in production. You will • Design and build Rust backend services handling real-time policy checks at scale. • Own features end-to-end – API design, schema, deployment, monitoring. • Improve performance and reliability through connection pooling, caching, query optimization, and observability. • Collaborate directly with product and research. Requirements • Production experience with Rust, Python, or Go. • Comfortable with async Rust (Tokio), Axum/Actix, and PostgreSQL – schema design, query optimization, debugging. • Strong system design fundamentals: trade-offs, failure modes, scaling. • Relocation to Paris or London (hybrid) required. Stack • Rust, Tokio, Axum/Actix, PostgreSQL. • Bonus: ClickHouse, Redis, Kafka, LLM infra (routing, inference, RAG), or high-throughput monitoring background. We offer • $80k–$150k/year salary + equity; higher figures can be negotiated. • Official employment, visa and relocation help. Compensation: $80K – $150K • Higher figures and equity are negotiable • • $80K – $150K • Higher figures and equity are negotiable Find more English Speaking Jobs in France on Arbeitnow