Senior Machine Learning Engineer

Senior Machine Learning Engineer

Zendesk

Krakow, Lisbon or Remote

We are looking for a Senior ML Engineer to join our AI Copilot organisation. AI Copilot is a multi-million ARR product that puts AI directly into the hands of customer service agents and administrators. You will own the delivery of ML-powered product features at Zendesk scale, taking capabilities from prototype through to production.

What you'll be doing

• Own and deliver ML-powered product features end-to-end — from data pipelines and model integration through serving, monitoring, and iteration in production.
• Work closely with Scientists to productionise research outputs into reliable, user-facing features.
• Build and maintain ML infrastructure: model serving, inference pipelines, LLM integrations, and evaluation frameworks.
• Contribute to technical design discussions and architecture decisions within your team, with growing influence across teams.
• Collaborate with product software engineers to ensure ML capabilities are well-integrated into the broader product experience.
• Improve the reliability, performance, and cost-efficiency of the ML systems you work on — proactively identifying and addressing issues.
• Mentor more junior engineers through code review, pairing, and knowledge sharing.

What you bring to the role

Required

• 5+ years of experience in software engineering, with a meaningful focus on ML engineering, MLOps, or building ML-powered products.
• Fluent in Python; working proficiency in Ruby is a plus.
• Solid experience building and operating ML systems in production: model serving, inference pipelines, and monitoring.
• Experience integrating LLMs into production systems — prompt engineering, evaluation, or multi-provider setups.
• Comfortable with SQL and data infrastructure — you can work with data pipelines, transformations, and data quality.
• Experience with containerised deployments (Docker, Kubernetes) and cloud infrastructure (AWS).
• A track record of owning features end-to-end and delivering them to production with high quality.
• Ability to work with uncertainty and the flexibility to pivot with changing priorities.
• Strong collaboration skills — you work effectively with scientists, product engineers, and product managers.

Preferred

• Experience with Snowflake and dbt for data transformations and analytics.
• Hands-on experience with ML pipeline tooling (e.g., Metaflow) and experiment tracking (e.g., MLflow).
• Experience with model serving frameworks (e.g., BentoML) on Kubernetes.
• Familiarity with ML frameworks such as PyTorch or TensorFlow.
• Experience with event-driven architectures (e.g., Kafka).
• Experience with iterative, metrics-driven product development (A/B testing, feature flags, incremental rollouts).

Tech Stack

• Our code is written in Ruby and Python
• Our servers live in AWS
• Our ML pipelines use Metaflow
• Our experiment tracking uses MLflow
• Our models are served via BentoML on Kubernetes
• Our data is stored in S3, RDS MySQL, and Snowflake (with dbt for transformations)
• Our services and models are deployed to Kubernetes using Docker
• Heavy usage of LLM technology from multiple providers via our LLM Proxy