Senior Software Engineer, Data Platform

NestAI; Helsinki; On-site; EUR 90,000 - 120,000; Full time

Benefits offered by this job

ESOP

Healthcare

Epassi Flex

Holiday pay

Phone benefit

Mac or PC

Team lunches

Job summary

NestAI is building an adaptive operating system for defense-grade data platforms. We offer an opportunity to own the Data Platform infrastructure, including storage, streaming, and compute components, with significant technical ownership and cross-team collaboration.

This is a senior role ideal for someone who thrives in ambiguous, high-impact environments and wants to help shape the platform strategy and its execution.

Qualifications

• Solid Python programming skills with grounding in software architecture.
• Experience designing, tuning, and operating distributed storage and streaming architectures (Iceberg, Kafka) under high-throughput constraints.
• Production experience running infrastructure in containerised, cloud-native environments with Kubernetes and Docker.
• Proven track record of designing, deploying, and operating complex backend or data systems in production through multiple iterations of a product life cycle at a senior level.
• Experience mentoring other engineers and raising the technical bar within a team.

Responsibilities

• Own the technical direction of the platform, including the streaming infrastructure, the lakehouse storage layer, and the compute infrastructure that every other R&D chapter builds on top of.
• Apply sound software architecture and design principles to systems that are built to last as NestAI scales.
• Collaborate directly with every engineering chapter in R&D, who rely on the platform as an internal customer, to understand their needs and shape what gets built next.
• Mentor other engineers on the team, sharing context on the platform's architecture and helping them grow their technical judgement.
• Take ownership of features end to end, from early design through production, in an environment where a lot of the foundation doesn't exist yet.
• Leverage AI assisted tooling to accelerate engineering velocity and architectural prototyping.

Skills

Python programming

Software architecture

Mentoring engineers

Ownership mindset

Architectural judgement

Tools

Apache Iceberg

Kafka

Kubernetes

Docker

Job description

NestAI builds the adaptive operating system for modern battlefield operations. Most AI systems are built once, validated at deployment, and expected to stay sufficient after that. That assumption holds until conditions change, and in defence, they always do. Our team develops adaptive intelligence for unmanned and command systems: AI that continuously learns from operational data and adapts to changing conditions, deployed in environments where there is no internet, no GPS, and failure is not an option. NestOS, our open, modular, and interoperable platform, 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 has grown to over 200 engineers and scientists and partners with leading European defence forces and industry. We're ambitious about what we're building and honest with each other. The bar is high, and so are the standards we hold ourselves to. But this is also a place built on humility, trust, and looking after each other. If that sounds like the kind of work you want to do, keep reading.

Join us as a Senior Software Engineer, Data Platform

You’ll join the Data Platform Chapter, the team building the infrastructure that every data engineer and R&D chapter at NestAI relies on. This is a build role, not a data engineering role: you won't be running pipelines on top of the platform, you’ll be building the platform itself, largely from the ground up. It's a senior role for someone who wants real ownership over foundational systems and their technical direction, is comfortable working with a lot of ambiguity, and is ready to help shape how the rest of the team approaches that work.

What you’ll work on

• The team you're joining builds the storage, streaming, and compute infrastructure that every other engineering chapter at NestAI relies on. In this role, you will:
• Own the technical direction of the platform, including the streaming infrastructure, the lakehouse storage layer, and the compute infrastructure that every other R&D chapter builds on top of.
• Apply sound software architecture and design principles to systems that are built to last as NestAI scales.
• Collaborate directly with every engineering chapter in R&D, who rely on the platform as an internal customer, to understand their needs and shape what gets built next.
• Mentor other engineers on the team, sharing context on the platform's architecture and helping them grow their technical judgement.
• Take ownership of features end to end, from early design through production, in an environment where a lot of the foundation doesn't exist yet.
• Leverage AI assisted tooling to accelerate engineering velocity and architectural prototyping.

What We’re looking for

If your background doesn't match every requirement but the work resonates with you, we’d encourage you to apply. How you think, learn, and take ownership matters more to us than ticking every box. Here is what we are looking for:

• Solid programming skills in Python, paired with a solid grounding in software architecture and design principles.
• Demonstrated experience designing, tuning, and operating distributed storage and streaming architectures, such as Apache Iceberg and Kafka, under high-throughput constraints.
• Production experience running infrastructure in containerised, cloud-native environments, with tooling such as Kubernetes and Docker.
• Proven track record of designing, deploying, and operating complex backend or data systems in production throughout multiple iterations of a product life cycle on a senior level.
• Experience mentoring other engineers and raising the technical bar within a team.

Nice to have:

• Experience with additional programming languages, such as Go or Rust.
• Familiarity with the broader open-source data tooling landscape, spanning compute and query engines, storage systems, and data cataloging or lineage tools.
• Work alongside over 200 engineers and scientists, including 60+ PhDs. People who've built AI platforms, autonomous systems, and defence technology across Europe. Most of our people say the best thing about NestAI is the people you get to work with.
• Work with real ownership. You identify what needs building, talk to the right people, and ship. Ownership here is the expectation, not a talking point.
• Work at a pace where Monday's idea can be Friday's deployment. The problems we're solving are urgent, so the culture reflects it.
• Work on systems that must operate with no connectivity, no GPS, and no margin for error. The problems we're solving are technically hard, genuinely novel, and they sit at the intersection of AI and the physical world.
• Work at a company where the platform, the practices, and the standards are all being built right now. The people here get to define how things work and how they scale.

What we offer

We offer practical benefits to support your work and wellbeing:

• The chance to participate in the NestAI Employee Stock Option Program (ESOP)
• Occupational healthcare (currently provided by Mehiläinen)
• Epassi Flex benefit for sports, culture, commuting, and wellbeing
• Holiday allowance (50% of holiday salary)
• Phone benefit (subscription and device per company policy)
• Your choice of Mac or PC
• Regular team lunches and company events

We are continuously developing our benefits offering as we grow.

Good to know

This role requires a security clearance, which is standard for defence industry positions in Finland. The process is handled by the relevant authority and typically takes two to three months. You can start working at NestAI before the clearance is finalised. We are happy to answer any questions about the process during the recruitment.

Relocation support is considered on a case-by-case basis.

Please note, we can't accept applications sent via email.

NestAI is an equal opportunity employer.

We evaluate all applicants on their skills, experience, and potential, regardless of background, identity, or personal characteristics.

We believe the best teams are built from diverse perspectives, and are committed to creating an environment where everyone can do meaningful work.