Principal AI/ML Architect & Agent Platform Lead

Harnham; California (MO); On-site; USD 180,000 - 280,000; Full time

Job summary

Harnham is partnering with a well-funded, high-growth startup to lead the technical direction of its AI-native data infrastructure. The role focuses on shaping agent architectures, evaluation strategies, and retrieval systems while owning end-to-end delivery of large-scale AI initiatives with real ownership over outcomes.

You will drive core AI capabilities, set coding standards, and mentor engineers across the organization in a highly ambiguous, fast-moving environment.

Qualifications

• 8+ years of software engineering with significant AI/ML depth and leadership.
• Experience owning AI agents in production at scale.
• Strong Python skills with RAG, vector databases, and knowledge graphs (Neo4j).
• Ability to make architectural decisions under uncertainty and drive to production.
• Experience with AWS and Kubernetes and full AI development lifecycle.
• Experience with data platforms such as Databricks, Snowflake, BigQuery, or Spark is a strong plus.
• Scala or Go experience is a bonus.

Responsibilities

• Set technical direction across multi-step agent architecture, RAG pipelines, and knowledge retrieval systems.
• Own the AI behind the platform's core code generation capability, including prompt design and fine-tuning.
• Lead large, complex initiatives end-to-end with minimal direction, defining the problem as much as the solution.
• Shape how production AI gets built across the team, establishing standards for evaluation, observability, and reliability.
• Influence architectural decisions across the broader engineering organisation and mentor engineers at all levels.

Skills

AI leadership

Python

Architectural decision making

Production AI experience

Tools

Neo4j

AWS

Kubernetes

Databricks

Snowflake

BigQuery

Spark

Scala/Go (bonus)

Job description

Harnham is partnering with a well-funded, high-growth startup to lead the technical direction of its AI-native data infrastructure. The role focuses on shaping agent architectures, evaluation strategies, and retrieval systems while owning end-to-end delivery of large-scale AI initiatives with real ownership over outcomes.

You will drive core AI capabilities, set coding standards, and mentor engineers across the organization in a highly ambiguous, fast-moving environment.