Backend Engineer

Job Summary:

Job Description:

Why this role is different

• It's applied, not research. We use proven commercial models and win on integration, retrieval, orchestration, and safety validation. Fine-tuning is an optional track, not the goal.
• It's domain-first, not tech-first. Domain knowledge - through retrieval and evaluation - is the moat, not model weights. You'll invest early in the customers' domain.
• It's production-first. We ship AI customers depend on daily. Demos don't count; reliability, cost, and safety do.
• It's platform AND product. You build reusable AI capability while enabling products to ship features fast.
• It's a founding role - you help build the team. As a founding AI hire you'll set the patterns and evaluation discipline the team adopts, and help hire.
• It's value-based. You'll validate with product teams and customers and prioritize by value - building what moves outcomes, not what's novel.

What You'll Do

AI Runtime & Orchestration

• Build and operate the runtime, tool calling, and orchestration for production agent workflows.
• Design model selection and tiering with cost and latency as first-class constraints.
• Implement and tune retrieval (RAG) and grounding where it measurably improves quality.

Evaluation, Safety & Quality

• Stand up evaluation harnesses and golden sets, and use them to make ship / no-ship calls and catch regressions and drift.
• Build guardrails and safety controls; treat retrieved content and tool outputs as untrusted.
• Design and implement evaluation frameworks for model and agent quality.

Production Ownership

• Own the production behavior of what you ship - latency, cost, reliability, and failure modes.
• Partner with product to decide when an agent is, and isn't, the right tool.

Delivering Value with Product & Customers

• Work with product teams and customers to validate results and outcomes, prioritizing by value.
• Take a value-based development approach: prove value with the smallest useful slice, then scale what works.
• Instrument and measure impact; let evidence - not opinion - drive what ships.
• Build automated QA - tests, quality gates, and regression checks - into the delivery pipeline.

Building the Team & Ways of Working

• Help build the team: set evaluation and safety patterns others adopt, raise the bar in interviews, and mentor.
• Foster a culture of technical excellence, customer obsession, and pragmatic shipping.
• Partner with product teams across the portfolio who own their own roadmaps.

What You'll Bring

We look at demonstrated experience and scope, not years served - and we don't expect every candidate to tick every box.

• Production AI: You've shipped software backed by LLMs or ML to real production users - beyond demos and notebooks.
• Evaluation over vibes: You reason about evaluation, not just prompting.
• Cost & latency: You treat cost and latency as design constraints from the start.
• Clear communication: You explain your thinking clearly to engineers, product partners, and customers, and bring people along.
• Value and pragmatism: You focus on outcomes and value and make pragmatic calls to ship.

Bonus Points

Any of these strengthen an application - none are required:

• Agents in production: Agent or RAG systems in production, and the failure modes that come with them.
• Routing & cost wins: Model routing or measurable cost-reduction.
• Calibrated eval: Evaluation harnesses driving decisions; LLM-as-judge calibrated against humans.
• Optimization track: Fine-tuning or distillation.
• Judgment: Knowing when NOT to use an agent.
• Languages: Strength in Python or C#/.NET.
• Semantic data: Experience grounding AI in structured, well-modelled business data.
• Architecture experience: System/platform design and trade-off judgement - one-way vs two-way doors.
• Enterprise scale: Experience building or operating enterprise-scale software and its reliability, security, and integration demands.
• AI-assisted engineering: You use AI coding assistants productively and supervise their output with judgement.

New to some of this? If you bring the essentials above and are excited by the problem, we'd still like to hear from you.

Worker Type:

Number of Openings Available:

About Us

Modaxo is a global technology organization passionate about moving the world’s people. Working both together and independently, our collective of businesses are committed to delivering software and technology solutions that help connect people with the places they need to go for work, family, and everyday life. No other organization brings together so many different businesses, competencies, and experiences under one global banner to focus exclusively on People Transportation.

Meaningful work, hard-working colleagues, intellectual stimulus, socially creative, purposefully driven, and many opportunities to learn and grow. We invest in our people.