Backend Engineer

About zaimler

AI agents can't reason over data they don't understand. Enterprise data today is fragmented across dozens of systems with no shared context, meaning, or structure, and that's why most enterprise AI is failing. The shift from copilots to autonomous agents is creating an entirely new infrastructure layer, and we're building it.

zaimler is the context infrastructure for the agentic era: a platform that automatically discovers domain knowledge, maps relationships, and gives AI agents the semantic understanding to operate with precision gine knowledge graphs that support real-time inference, built for systems that need to reason, not just retrieve.

zaimler was founded by Biswajit Das (ex‑VP Engineering, Truera), a Data Infra veteran and former Chief Architect at Visa, and Sofus Macskassy (ex‑Director of Engineering, Linked In), who built one of the largest knowledge graphs in production in the industry 're a small, senior team at the seed stage, deploying with major enterprises across insurance, travel, and technology. If you want to build infrastructure that the next decade of AI runs on, we'd love to talk.

We are seeking a Backend Engineer with deep experience in microservices architecture to join our team. The ideal candidate will have expertise in building and operating distributed backend systems using technologies like Java, Ray, Post Gres, and Kubernetes. In this role, you’ll be critical in designing, implementing, and scaling the core microservices that power our AI and data platform.

You’ll help define service boundaries, build robust APIs, and ensure reliable communication across our ingestion, extraction, and knowledge graph systems. We're looking for someone who brings strong backend engineering fundamentals and a track record of delivering production‑grade systems in fast‑moving environments.

• Design and implement core microservices that handle document ingestion, entity extraction, and graph construction
• Define and enforce clean service interfaces and communication protocols (e.g., gRPC, REST)
• Drive schema design and service ownership in a polyglot environment (Java + Rust)
• Contribute to deployment and runtime infrastructure (Helm, Kubernetes, vLLM, Ray)
• Build internal tooling and APIs that accelerate downstream teams working on retrieval and ranking
• Help scale systems as we ingest more enterprise data and expand graph resolution logic

• Have 4+ years of experience building backend services in modern cloud environments
• Are fluent in at least one strongly typed language (Rust, Java, etc.) and comfortable in dynamic ones (Python)
• Understand distributed systems, service discovery, and observability (we use Open Telemetry + Grafana)
• Have experience implementing secure APIs and backend systems, including RBAC, authentication, and authorization patterns
• Have strong opinions on API boundaries, fault tolerance, and making systems boring (in a good way)
• Enjoy taking vague problems and turning them into clean, testable services
• Are comfortable working in a high‑context, fast‑moving startup environment with minimal overhead

• Experience working with knowledge graphs, embeddings, or semantic search
• Familiarity with vLLM, Ray, or distributed compute runtimes
• Background in data‑intensive systems or working with unstructured inputs
• Exposure to entity resolution, NER, or schema linking systems

• A rare chance to be a founding engineer shaping both company and product direction.
• Competitive salary, benefits, and meaningful equity.
• Work alongside engineers and researchers from Linked In, Visa, Meta, and Branch.
• Onsite culture in San Mateo, designed for deep collaboration and high‑velocity building.
• Full benefits package (Medical, Dental, Vision, 401k).
• We sponsor H-1B visas and assist with immigration processes.

We value builders over résumés. If this role excites you but you don't check every box, we still want to hear from you. zaimler is an equal opportunity employer.