Synthetic Data Generation Engineer

NestAI; Helsinki; On-site; EUR 120,000 - 160,000; Full time

Benefits offered by this job

Occupational healthcare

Epassi Flex benefit

Lunch benefit

Team lunches

Mac or PC choice

Holiday allowance

Phone benefit

Job summary

NestAI is building an open, modular platform for sovereign European defense AI. Join the synthetic data team to develop pipelines that generate photorealistic data for robust object detection in defence contexts.

You will train diffusion-based models, including LoRA fine-tuning, and evaluate synthetic data by its impact on real-model performance. This role focuses on research-driven data generation to close data gaps.

Qualifications

• Several years of hands-on experience training generative models yourself.
• Experience creating synthetic data in domains with limited real data.
• Deep familiarity with diffusion models and Python ML training frameworks, including LoRA and Hugging Face Diffusers.

Responsibilities

• Build and improve generative pipelines that produce synthetic image and video data for object detection models.
• Train and fine-tune diffusion-based generative models, including LoRA fine-tuning.
• Combine generative approaches with other data sources to boost realism and variation.
• Validate synthetic data against real-world outcomes to prove training benefits.
• Track new open-source models and evaluate landscape shifts.
• Collaborate with ML Platform chapter and simulation team on data infrastructure.

Skills

Hands-on generative modeling

Synthetic data creation

Diffusion models

LoRA training

Python ML frameworks

Judgment on data realism

Umgang with imperfect information

Tools

Hugging Face Diffusers

LoRA training

Job description

Company

NestAI is a European AI lab for defence delivering the adaptive operating system for modern battlefield operations. We develop adaptive intelligence for unmanned and command systems: AI that continuously learns from operational data and adapts to changing conditions.

NestOS is our open, modular and interoperable platform that enables this at scale and keeps capability evolution under sovereign European control. Founded in 2025 by Peter Sarlin, whose previous company Silo AI became Europe's largest AI acquisition, NestAI brings together over 200 engineers and scientists and partners with leading European defence forces and industry.

Role Description

You'll join the synthetic data team inside our ML Platform chapter, the group responsible for generating training data that doesn't exist anywhere else yet. Real-world imagery for object detection in defence contexts is scarce by nature: the situations, assets, and conditions our models need to recognize are rare, hard to capture safely, or simply haven't happened yet. This team builds the generative pipelines that close that gap, generating visual data under controlled conditions for scenarios that are difficult to capture directly. This role is for someone who has trained generative models themselves, not just fine-tuned or called pretrained ones, and who cares as much about whether synthetic data holds up in real-world model performance as about whether it looks convincing.

Day-to-Day Responsibilities:

Since high-quality real-world imagery for our use cases is scarce, this team's job is to generate data that closes the gap without compromising downstream detection performance.

• Build and improve generative pipelines that produce synthetic image and video data for object detection models, covering scenarios where real data is scarce or unavailable.
• Train and fine-tune diffusion-based generative models, including LoRA fine-tuning, to produce increasingly realistic and varied synthetic data.
• Combine generative approaches with other data sources to boost realism and variation and increase variation in the data produced.
• Validate synthetic data against real-world outcomes, proving it improves model training, not just that it looks good.
• Track the fast-moving generative model landscape and evaluate new open-source models as they emerge.
• Work closely with the wider ML Platform chapter and simulation team on shared data infrastructure.

Qualifications:

• Several years of hands-on experience training generative models yourself, not only fine-tuning or calling pretrained APIs.
• Experience creating synthetic data in domains where real data is limited — image-based fields like medical, hyperspectral, or multispectral imaging are a strong analogue, even outside defence.
• Deep familiarity with diffusion models and Python-based ML training frameworks, including LoRA training and the Hugging Face Diffusers library.
• Judgment for when synthetic data is realistic enough to actually matter for training, and when it isn't, however good it looks.
• Comfortable working with imperfect information in a research area that shifts month to month.

Nice to have:

• Experience with Nvidia Omniverse or other simulation environments, and combining simulation output with generative models.
• Exposure to generative world models.
• Background in a field where generating photorealistic, cost-efficient synthetic scenes at scale mattered (e.g. automotive or gaming).

Why join NestAI

At NestAI, you’ll build meaningful, real-world technology as part of a world-class team of engineers, scientists, and experienced professionals. You’ll work on systems where reliability genuinely matters, contribute to Europe’s security and resilience, and solve problems that demand depth, trust, and craftsmanship.

If you want to build with purpose - and with leading experts in the field - you’ve come to the right place.

What we offer

We offer a growing set of practical benefits to support your work and wellbeing, day to day:

• Occupational healthcare (currently provided by Mehiläinen)
• Epassi Flex benefit (sports, culture, commuting, wellbeing)
• Lunch benefit (25% tax-free coverage)
• Regular team lunches and all-hands events
• Your choice of Mac or PC
• Holiday allowance (50% of holiday salary)
• Phone benefit according to company policy (subscription and device)
• We are continuously developing and expanding our benefits as we grow.

Practicalities

Employment is subject to applicable security screening (including SUPO, where required).

NestAI is an equal opportunity employer. We consider all applicants based on their skills, experience, and potential.