Senior AI Engineer

Senior AI Engineer

Job location: US

Colt provides network, voice and data centre services to thousands of businesses around the world, allowing them to focus on delivering their business goals instead of the underlying infrastructure. Summary

Job title: Senior AI Engineer

Reports to: VP of AI Technology and Architecture

Job location: Must have ability to be onsite in Boulder, CO office for 2-3 days a week

About Colt and the AI Practice

Colt Technology Services is a global digital infrastructure company, operating one of the world's largest fiber networks across Europe and Asia. We are building a Boulder-based AI team as the engineering center of our AI Practice. The team is responsible for how AI is adopted, governed, and scaled across Colt. The AI Practice operates across several parallel workstreams, including use case delivery, AI WAN, and private AI. The Boulder team is where we build, test, and validate before we scale.

Why we need this role

This is a build role. You will take AI use cases from a business problem to something running in production and being used every day: retrieval and search over Colt's own data, agents that carry out multi-step work, and AI built into the systems Colt's teams already rely on. We are looking for a strong software engineer first. If you have spent eight to ten years building and running production systems and even if you have not yet shipped an LLM-based product, we want to hear from. The platform, the tooling, and the model access are already in place, and a staff-level AI engineer on the team will pair with you directly on the AI side of the work. The AI-specific skills you can bring to the table is a plus but is also learnable. The engineering experience and judgement that comes from having owned real systems in production is not, and that is the part we are hiring for. We expect that you have already got hands on with AI, whether at work or as a side project for yourself.

What you will do

Build AI Use Cases

Design and build AI applications end to end: data access, retrieval, model calls, orchestration, and the interfaces people use

Work with large language models through APIs and self-hosted inference, covering prompting, tool use, retrieval, and multi-step agent workflows

Build evaluation harnesses that show whether a use case is good enough to ship, and keep owning them after it ships

Integrate AI into Colt's existing systems and data, within the constraints of a live enterprise environment

Work Directly With the Business

Work with the Colt teams, who will be your customers, and who will use what you build, across network operations, service delivery, finance, and others

Turn a loosely described business problem into a scoped, buildable design

Show working software early and often, and change direction when the first answer turns out to be wrong

Be straight with stakeholders about what AI is not the right tool for

Take It to Production and Keep It There

Move your own work from prototype to production-grade: tested, instrumented, documented, and supportable

Monitor accuracy, latency, and cost in production, and act when they drift

Work with platform engineers on deployment, and hand over cleanly to production operations

Contribute reusable patterns, components, and internal libraries so the next use case is faster than the last

What we're looking for

Engineering Experience: 8-10+ years building production software. You have owned systems end to end: designed them, shipped them, operated them, and been on the hook when they broke.

Languages: Strong in Python, or strong in another language such as Java, Go, C#, or TypeScript and ready to work primarily in Python.

Production Systems: APIs and service integration, working with real data at scale, testing, CI/CD, and debugging things that are already live in front of users.

Cloud: Comfortable in any major cloud. We build primarily on Google Cloud; equivalent AWS or Azure experience is ok to start.

Working Style: Comfortable with ambiguity and with direct contact with non-technical stakeholders. You ask what the problem is before deciding what to build.

Hands-On with AI: You have already built something with it under your own steam. A side project, a prototype at work, an internal tool, a serious evaluation you ran, or agentic coding tools you use daily and have opinions about. It does not need to have shipped, been finished, or worked.

Helpful, Not Required: Any of this at enterprise scale: production RAG over messy real-world data, agent frameworks, evaluation tooling, Vertex AI, Kubernetes, Terraform. Useful if you have it, and teachable if you do not.

HOW YOU WILL RAMP

You pair with a staff-level AI engineer from your first week, on a live use case rather than a training exercise

The AI platform is already running: model gateway, evaluation tooling, deployment pipelines, and sandbox, development, and production environments

We expect you to put something small into real use inside your first 90 days, and to lead a use case end to end within six months

WHEN WE TALK

Come ready to walk us through something you have built with AI, however small or unfinished. We would rather see a rough prototype you can explain in depth than a polished project you cannot. Expect us to ask where it fell short, what you would do differently, and how you decided whether it was any good. How you evaluated it matters more to us than what you shipped. If you have not used AI tools in your own engineering work, this will be a difficult conversation. That is the one gap we are not set up to close for you.

What we offer you:

Looking to make a mark? At Colt, you'll make a difference. Because around here, we empower people. We don't tell you what to do. Instead, we employ people we trust, who come together across the globe to create intelligent solutions. Our global teams are full of ambitious, driven people, all working together towards one shared purpose: to put the power of the digital universe in the hands of our customers wherever, whenever and however they want. We give our people the opportunity to inspire and lead teams, and work on projects that connect people, cities, businesses, and ideas. We want you to help us change the world, for the better.

Diversity and inclusion

Inclusion and valuing diversity of thought and experience are at the heart of our culture here at Colt. From day one, you'll be encouraged to be yourself because we believe that's what helps our people to thrive. We welcome people with diverse backgrounds and experiences, regardless of their gender identity or expression, sexual orientation, race, religion, disability, neurodiversity, age, marital status, pregnancy status, or place of birth. Most recently we have:

Signed the UN Women Empowerment Principles which guide our Gender Action Plan

Trained 60 (and growing) Colties to be Mental Health First Aiders

Please speak with a member of our recruitment team if you require adjustments to our recruitment process to support you. For more information about our Inclusion and Diversity agenda, visit our DEI pages.

Benefits

Our benefits support you through all parts of life, for both physical and mental health. Flexible working hours and the option to work from home. Extensive induction program with experienced mentors and buddies. Opportunities for further development and educational opportunities. Global Family Leave Policy. Employee Assistance Program. Internal inclusion & diversity employee networks. A global network When you join Colt you become part of our global network. We are proud of our colleagues and the stories and experience they bring – take a look at 'Our People' site including our Empowered Women in Tech.