# Senior Software Engineer, Applied AI

**Company:** [Justworks](https://hotfix.jobs/companies/justworks)
**Location:** Toronto, Canada
**Role:** Backend Engineering
**Salary:** £132k – £170k/yr
**Experience:** 5+ years
**Skills:** Go, Ruby on Rails, JavaScript, Java, C#, Python, Vue, MySQL, Kafka, AWS, Redis, Elasticsearch, Docker, Terraform, Kubernetes
**Posted:** 2026-08-05

> Build and operate backend infrastructure for an AI agent platform, including orchestration, integrations, knowledge and memory systems, and trust and safety controls. The role requires 5+ years of backend experience, practical LLM or agent experience, strong API skills, and ownership in an ambiguous product environment.

## Job Description

## Responsibilities

- Design, build, and own core components of the agent platform, including the orchestration layer and tool integrations with internal systems.
- Build and evolve the capabilities layer, including APIs, data access patterns, and service integrations for agents to execute operational workflows.
- Architect knowledge and memory infrastructure so agents can retrieve data and act across systems.
- Design and implement trust and safety frameworks, including audit trails, human-in-the-loop controls, and guardrails for safe, auditable AI-driven operations.
- Contribute to agent evaluation and testing infrastructure, defining measures for accuracy, reliability, and behavioral regressions.
- Partner with Operations to understand workflows, identify automation opportunities, and translate process knowledge into agent capabilities.
- Mentor other engineers as the team grows.

## Requirements

- 5+ years of backend engineering experience building and operating production systems.
- Hands-on experience with LLMs and AI agents, including orchestration, retrieval-augmented generation, tool or function calling, or similar.
- Strong API design and system integration skills.
- Product-minded approach, including questioning requirements and contributing to product decisions.
- Proven ownership of complex projects in ambiguous, early-stage environments.
- Strong backend engineering fundamentals and the ability to design, build, and operate production systems.
- Curiosity and motivation to build practical products using AI and LLMs, particularly agent systems.

## Technologies

- Golang
- Ruby on Rails
- JavaScript
- Java
- C#
- Python
- Vue.js
- MySQL
- Kafka
- AWS
- Git
- Memcached
- Redis
- Elasticsearch
- Docker
- Terraform
- Kubernetes
- CircleCI
- Datadog

## Compensation

- Base wage range for positions based in the United Kingdom: **£132,000–£170,000 per year**.

## Similar jobs

- [Senior Product Engineer](https://hotfix.jobs/jobs/70578999-e62a-4d80-b444-491e7a0d3c08) - Hospitable - Remote - $134k – $167k/yr
- [Senior Software Engineer, Device Identity](https://hotfix.jobs/jobs/bd779c69-a026-4775-949d-bff228853342) - Okta - Toronto, Canada - CA$136k – CA$187k/yr
- [Senior Software Engineer, Recommendations](https://hotfix.jobs/jobs/ee7d0c2b-036a-42d7-b134-a6e19872cbeb) - Lyft - Toronto, Canada - CA$136k – CA$170k/yr
- [Senior Software Engineer, AI Entries](https://hotfix.jobs/jobs/16362414-c00a-4fa2-b4a3-5906f37a48b0) - Lyft - Toronto, Canada - CA$136k – CA$170k/yr
- [Senior Python Engineer](https://hotfix.jobs/jobs/c8c55177-70aa-4b06-a473-066c24efa113) - MongoDB - British Columbia, Canada - CA$137k – CA$189k/yr

**Apply:** https://hotfix.jobs/jobs/9fb92e12-b245-4416-862b-d5b86d80fd77
**Canonical:** https://hotfix.jobs/jobs/9fb92e12-b245-4416-862b-d5b86d80fd77