Senior AI-Native Backend Engineer – Agent Platform

Justworks; Netherlands; On-site; EUR 143,000 - 184,000; Full time

Job summary

Justworks is hiring a Senior Software Engineer in the Netherlands to join a small, autonomous team building AI-native systems. You will own large portions of the tech stack, make pragmatic decisions in ambiguous areas, and ship production-ready systems students and teams rely on daily.

The role emphasizes building an agent platform, robust backend services, tool integrations, and knowledge infrastructure to scale operations at pace. Strong backend fundamentals and interest in AI are essential.

Qualifications

• 5+ years of backend engineering experience building and operating production systems.
• Hands-on experience with LLMs and AI agents (orchestration, RAG, tool/function calling, or similar).
• Strong API design and system integration skills.
• Product-minded: questions requirements and contributes to product decisions, not just execution.
• Proven ownership of complex projects in ambiguous, early-stage environments.

Responsibilities

• Design, build, and own core components of the agent platform, from the orchestration layer to the tool integrations connecting it to internal systems.
• Build and evolve the capabilities layer: APIs, data access patterns, and service integrations for agents to execute operational workflows.
• Architect the knowledge and memory infrastructure, allowing agents to retrieve the data and act across our systems.
• Design and implement the trust and safety framework, including audit trails, human-in-the-loop controls, and guardrails for safe and auditable AI-driven operations.
• Contribute to agent evaluation and testing infrastructure, defining how we measure accuracy, reliability, and regression across agent behaviors.
• Partner directly with Operations to understand workflows, identify automation opportunities, and translate process knowledge into agent capabilities.
• Mentor other engineers on the team as it grows.

Skills

Backend engineering

LLMs & AI agents

API design

Ownership

Product-minded

Tools

Golang

Ruby on Rails

JavaScript

Java

C#

Python

VueJS

MySQL

Kafka

AWS

Git

Memcache

Redis

ElasticSearch

Docker

Terraform

Kubernetes

CircleCI

DataDog

Job description

Justworks is hiring a Senior Software Engineer in the Netherlands to join a small, autonomous team building AI-native systems. You will own large portions of the tech stack, make pragmatic decisions in ambiguous areas, and ship production-ready systems students and teams rely on daily.

The role emphasizes building an agent platform, robust backend services, tool integrations, and knowledge infrastructure to scale operations at pace. Strong backend fundamentals and interest in AI are essential.