Agent Harness Engineer (KP)

Job Description

Career Opportunity: Agent Harness Engineer in Japan Tokyo (Hybrid) !

Agent Harness Engineer (English Required Japanese is a plus)

Company Overview

A fast-growing engineering-first technology company with over 80% engineers focused on driving innovation through strong technical leadership and continuous learning.

With a diverse global team across 25 countries the company works in small agile teams delivering high-impact solutions.

Key domains include:

FinTech: Modernizing financial systems payment platforms and core banking

PharmaTech: Building SaaS solutions to enhance R&D productivity

Design and build the core execution infrastructure (Agent Harness) that enables AI agents to operate securely efficiently and at scale.

You will develop systems powering hundreds of workflows on an in-house AI platform used by enterprises

Your Role and Responsibilities

The Agent Harness is the execution & control layer for AI agentshandling orchestration memory guardrails and model routinggoing beyond traditional backend engineering into a new AI-native domain.

Agent Harness Development

Design & build agent execution engines (state machines / graph runtime)

Develop Agent SDKs for internal engineers

Implement session management checkpoints recovery systems

Build guardrails & policy execution systems

AI/ML Integration

Model routing across multiple LLM providers

Design RAG memory systems (long-term & working memory)

Optimize inference (latency cost caching)

Collaborate with research teams to productionize new AI methods

Orchestration & Performance

Workflow orchestration queuing systems

Autoscaling load balancing cost optimization

Reliability & Operations

Maintain 99.9% uptime

Incident handling & system improvements

Access control & data security design

Experience and Qualifications

Bachelors degree (or equivalent) in CS AI Engineering or related field

5 years of backend engineering experience

Strong experience in Python (production systems)

Experience building LLM/AI-driven systems

Experience with distributed systems & APIs (REST/gRPC)

Language:English (Business level) OR Japanese (Fluent)

Tech Stack:

Backend: Python Go

Frontend: TypeScript React

Infra: GCP Kubernetes Docker Terraform

Messaging: Kafka Pub/Sub

Monitoring: Prometheus Grafana OpenTelemetry

Tools: GitHub Slack Notion Confluence

Good Reasons to Join

Work at the intersection of AI backend engineering

Build core infrastructure powering enterprise AI systems

High ownership in architecture & technical decisions

Collaborate in a fast-growing global AI environment

Work Location

Tokyo Japan (Hybrid)

Interested or know someone suitable Lets connect!

Share your updated CV at

Limited interview slots available early applicants preferred

Details will be provided during the meeting.