Platform Engineer · RaySearch Laboratories AB (publ)

RaySearch develops innovative software solutions to improve cancer care. Over 1200 clinics in more than 54 countries use RaySearch software to improve treatments and quality of life for patients. RaySearch was founded in 2000 and is listed on Nasdaq Stockholm. The headquarters is located in Stockholm, with subsidiaries in the US, Europe, Asia and Australia & New Zealand. Today we are more than 485 employees with a common vision of improving cancer care with innovative software. Our great staff is crucial for our success and we offer a fantastic working environment in modern offices, flexibility and good opportunities for development. We believe in equal opportunities, value diversity and work actively to prevent discrimination.

RaySearch is expanding its machine learning capabilities and is looking for a Machine Learning Platform Engineer to join our headquarters in Stockholm. This is an office-first role.

You will help build our model development platform: the systems that take clinical data through curation, training and validation to deployed models. Our deep learning models are used in RayStation, our treatment planning system, at cancer clinics worldwide. The platform you build is how the next generation of these models gets made.

This is not primarily a model development role. Your focus is the platform, data and infrastructure that let ML engineers develop, validate and deploy models reliably.

About the job

You will join RaySearch's Machine Learning department and help build a platform that covers the full model lifecycle, from clinical data coming in to validated models going out.

The work spans:

Data curation and management: ingesting, organizing and validating large clinical datasets and medical images, with ETL, databases and storage that keep track of where data came from and how it was used.

Model training: reproducible training pipelines orchestrated with Flyte, for dose prediction, segmentation, detection, classification and image registration, with monitoring of training runs.

Validation: automated evaluation and reporting that connects data, method, code and results, including web-based tools for reviewing images, contours, radiotherapy plans and validation outcomes.

Deployment and ML integration: getting models into production and integrated into our software products, including inference optimization.

Operations: monitoring training and evaluation runs, keeping services and databases up to date, and troubleshooting when things go wrong.

The platform is used by multiple teams and projects, so good design matters: well-designed APIs, solid documentation and reliable services. You will own services from design to operation and work closely with ML engineers, software developers, infrastructure teams, medical physicists and product teams.

Your profile

You are an experienced software engineer who enjoys building systems that help others do their best work. You are pragmatic: you know when a simple solution is enough and when the problem needs a more scalable architecture. You care about reliability, automation and developer experience. You like building platforms that are robust and well-designed enough to serve many different users.

You don't need to spend your days training neural networks. You do understand how ML development differs from traditional software engineering, and you find problems like reproducibility, data lineage, model versioning, large datasets and GPU workloads interesting.

Requirements

M.Sc. in Computer Science, Software Engineering, Machine Learning or equivalent experience, and at least 5 years of professional software engineering.

Strong Python skills and experience designing backend services and APIs.

Solid knowledge of relational databases and data modeling, such as PostgreSQL.

Experience with containers, for example Docker, and with designing, running and troubleshooting production services.

Good engineering practices: automated testing, code review, CI/CD and observability.

Experience contributing to architecture decisions in large, shared codebases.

Excellent spoken and written English.

Meriting

Experience in one or more of the following areas is considered an advantage:

ML platforms and MLOps tooling, such as MLflow and experiment tracking.

PyTorch, and model deployment or inference optimization, such as TensorRT.

Workflow orchestration and ETL. We use Flyte, but experience with Airflow, Prefect, Dagster or similar is just as relevant.

Kubernetes, cloud platforms and infrastructure as code.

Designing platforms and APIs used by many teams or users, including access control and security.

Operating production services with high reliability requirements.

Web application development.

Medical imaging (DICOM, RT structures), healthcare technology or other regulated, safety-critical environments.

Our Culture

At RaySearch, we share a passion for innovation and the fight against cancer. Our team consists of dedicated experts who strive to deliver exceptional results through collaboration, attention to detail, and cutting-edge technology. We take pride in our role as a leader in cancer treatment, developing solutions that truly make a difference for patients worldwide.

Our Offer

We offer a dynamic and inclusive work environment in Hagastaden, Stockholm’s Life Science Hub. Our modern office space includes an in-house gym, yoga classes, and social activities such as ping pong, table football, and after-work events. We also provide a fantastic lunch buffet, daily fika, and a stunning rooftop terrace with a 360-degree view of Stockholm. This comes with a competitive compensation and benefits package.

Application

Please apply for the position through the application form below. Selection and interviews will be ongoing. We do not accept applications via e-mail.