Senior Applied ML Engineer - Remote-First Model Router

Cast AI; Italy; Remote; EUR 125,000 - 178,000; Full time

Benefits offered by this job

Competitive salary

Equity options

Remote-first environment

Learning budget

Hackathons

Team events

Equipment budget

Personal project time

Job summary

Cast AI is seeking an experienced Platform ML Engineer to own the routing model end-to-end, including features, objectives, training, and release cadence. You will build robust evaluation pipelines with production-parity checks and convert fleet data into actionable training signals, ensuring reliable, cost-aware decisions in a live environment.

Join a remote-first global team driving real-time routing for AI workloads, with equity options, flexible work hours, and a strong focus on

Qualifications

• 5+ years in applied ML or ML research with real-time decision models (ranking, pricing, or routing).
• Strong Python and SQL skills for large-scale data.
• Ability to design, evaluate, and ship ML models in production.

Responsibilities

• Own the routing model end-to-end: features, objective, training, and release cadence.
• Build production-parity evaluation with proper error bars to gate changes.
• Turn fleet data into training signals with failure categorization to avoid poisoned labels.
• Model the objective to reflect user experience: task success × token cost × speed under concurrency.
• Run online experiments: shadow, A/B, full rollout, drift monitoring.

Skills

Applied ML

Python

SQL at scale

Model routing

Online A/B testing

System design

Data analysis

Tools

PyTorch

ClickHouse

OpenAI API

Anthropic API

GitLab CI

Job description

Cast AI is seeking an experienced Platform ML Engineer to own the routing model end-to-end, including features, objectives, training, and release cadence. You will build robust evaluation pipelines with production-parity checks and convert fleet data into actionable training signals, ensuring reliable, cost-aware decisions in a live environment.

Join a remote-first global team driving real-time routing for AI workloads, with equity options, flexible work hours, and a strong focus on