AI Engineer - Core

About the role

Hilbert is building a reasoning engine that must navigate non-deterministic user behavior across data silos — turning months-long decision cycles into minutes. Fully agentic by design, our demand intelligence platform doesn't just call APIs; it solves the hard problem of orchestrating multi-step inference over messy, high-stakes enterprise data where deterministic answers don't exist. From Fortune 500 enterprises to beloved brands like FreshDirect, Blank Street, and Levain Bakery, operators run their growth on Hilbert. We're also co-building alongside leading AI companies. We're looking for an AI Engineer who can build production-grade AI systems end-to-end — from prototype to pipeline to product — with the ownership and urgency of a startup culture.

Responsibilities

• Own the evaluation layer for our agents — harnesses, metrics, golden datasets, regression gates, and human-in-the-loop review.
• Architect and implement agent workflows using LangChain, LangGraph, or equivalent; state memory, routing, tools registries and recovery paths.
• Own systems from experimentation through production and operate in production: tracing, monitoring, latency, cost-per-task budgeting, on-call for what you build.
• Diagnose real production failures: hallucination, tool misuse, retrieval misses, silent degradation and turn each into a durable fix and a test.
• Set the technical standard for agent work at Hilbert: review designs, define patterns others build on, and raise the bar across the team.
• Collaborate closely with the founding team and cross-functional partners — communicating tradeoffs, progress, and technical decisions with clarity.
• Make pragmatic engineering decisions under ambiguity—ship, learn, iterate.

Requirements

• 4+ years of production software engineering: APIs, services, data infrastructure. You've owned code that other people depended on, with tests, CI/CD, and on-call attached.
• 2+ years building LLM or agent systems that shipped to productions watching real users adopt. Not internal demos, not prototypes. Be ready to talk about what broke in production and what you did about it.
• Hands on with LangChain, LangGraph, or equivalent agent/orchestration frameworks. You've built with them, hit their limits, and worked around them. You operate beyond just following tutorials.
• You communicate with clarity and conviction. You can explain a technical decision to a non-technical founder and debate architecture tradeoffs with a senior engineer. Communication is not a nice-to-have here — it's core to the role.
• You take ownership. You don't wait for tickets. You see what needs to be built, raise your hand, and ship it.
• You thrive in ambiguity. AI products evolve fast. Requirements change. You're energized by figuring it out.
• You move at startup speed. Without waiting for permission, and you know which decisions deserve a day of thought and which deserve an hour.

Qualifications

We care about what you've shipped and how you think, but as a Senior, we expect you to demonstrate 4+ years of building production software, with at least 2 of those on LLM or agentic systems that real users depend on.

Skills

• Retrieval-augmented generation (RAG) at depth: Hybrid and graph retrieval, chunking and embedding strategy, ranking, grounding
• Observability for LLM systems (Langfuse, OpenTelemetry, or equivalent) and cost/latency optimization
• MCP, tool-calling frameworks, structured output and constrained decoding
• Experience at early-stage startups or high-growth environments where you wore multiple hats

Benefits

• Health & wellness: We cover 100% of your Health, Dental, and Vision premiums — with the option to add coverage for