AI Harness Engineer - Help build agents for the future

At Milestone Systems, we grow together - and your ideas will help shape our shared future.

Impact & Purpose

Ready to make an impact? In this role, you’ll take what's working and turn it into something the whole engineering organization can use.

You help set the standard for how the whole engineering org uses AI, not how one team does

New team with a new mandate, you're defining the playbook rather than inheriting one

Real constraints that most AI roles don't have: on-prem, air-gapped, EU AI Act, GDPR. Harder problems than the SaaS default

Location

We are looking for anAI Harness Engineer -Help build agents for the future, based in Sofia, Bulgaria (hybrid mode of working).

Role Summary

As an AI Harness Engineer, you’ll be responsible for everything around the AI models: the tooling, context setup, evaluations, guardrails, and cost controls that make AI dependable for actual engineering. The first focus is our internal development environment. After that, we want your help bringing the same rigor to the AI features and agents going into our products.

Part of the job is being straight with us about where AI doesn't help, not only where it does.

What You Will Do:

• Help build and maintain our AI coding setup: the agent loops, context handling, tool integrations, caching, and guardrails that keep these tools reliable in a large codebase.
• Take the experiments already working somewhere in the company and turn them into something other teams can pick up and run with.
• Stand up the evaluations and cost tracking, we need to tell whether a given tool is pulling its weight.
• Help recommend the build-versus-buy calls. We should buy most infrastructure; the parts tied to our products or our on-prem and compliance requirements are where building may make sense.
• Work with product teams to bring the same approach to customer-facing AI features, inside EU AI Act and GDPR.
• Get engineers on board the right way, by showing them, pairing with them, and writing things down, so the change sticks.

What You Bring to the Team:

• 5+ years of professional experience as a staff or senior engineer, you know the ins-and-outs of software engineering (.NET, C++, JS/TS, Java or similar)
• Real, hands-on familiarity with today's AI coding tools (Claude Code, Cursor, Copilot, Codex and the like) and the craft around them: context engineering, prompting, caching, tool, memory, and all the other jazz
• Strong fundamentals. When an agent fails, you can work out why and fix it rather than just file a ticket.
• A habit of treating tokens and computing spend as a real budget, and a sense of how-to bring cost-per-task down.
• The presence to stand in front of experienced, skeptical engineers, have hard conversations, and still bring them with you.
• A view that AI is a powerful tool, but that engineering judgment is what makes the difference, plus enough curiosity to keep up as the field shifts.

How You Will Make a Difference:

• You've shipped agentic features in product customers actually use.
• You have experience under EU AI Act or GDPR, or with on-prem and air-gapped deployments.
• You've set up an internal model gateway, LLM monitoring, or evaluation tooling.

About the Team

You’ll join a new team in the Experience Development Organization, a central new international team whose mission is to be our organization to get us on the edge of AI development.

You’ll be in a highly collaborate space, paired with AI Harness Engineers, and collaborating across the organization with AI Acceleration, Developer Experience, Arcules and Responsible AI stakeholders.

How We Support You:

• Individual development plans aligned with your career goals
• Access to training, learning resources, and professional development opportunities
• Flexible hybrid working arrangements
• Supportive leadership and regular feedback
• Opportunities for cross-functional and international collaboration
• A People First culture built on trust, inclusion, and empowerment
• Social activities and opportunities to connect with colleagues across the organization

What We Offer:

• Hybrid-friendly / flexible way of working
• 25 days’ vacation
• Employer covered luxury health and dental packages
• Best Doctors Insurance
• Transportation benefits
• Compliments gift card
• Food vouchers
• Multisport card covered by employer

If you’re ready to make a significant impact and take your career to the next level, we’d love to hear from you!

About Us

Milestone Systems is a leading provider of data-driven video technology software. Our portfolio includes XProtect video management software, Arcules video surveillance as a service, and BriefCam analytics. We amplify what organizations of any size can see, do, and achieve with video. Guided by our People First mindset-freedom, inclusion, and togetherness-we always consider our employees, partners, and communities in everything we do.