Principal LLM Engineer

Supercell; Helsinki; On-site; EUR 80 000 - 110 000; Full time

Job summary

A prominent game development company in Helsinki is looking for a Principal LLM Engineer to lead the craft of LLM engineering. The role involves setting high standards, developing applications, and driving the use of AI tools. Candidates should have a PhD in ML, strong software engineering skills, and experience in building production-grade LLM applications. A collaborative and proactive mindset is essential. The position supports relocation to Helsinki.

Benefits

Relocation assistance

Flexible work environment

Competitive compensation

Qualifications

• Deep expertise in building production-grade LLM applications.
• Real-world experience with evaluation and monitoring.
• Strong background in AI development tools.

Responsibilities

• Set direction and best practices for LLM engineering.
• Drive adoption of LLM applications.
• Act as a bridge between technical and non-technical teams.

Skills

LLM and agentic applications development

Software engineering skills

Excellent communication and evangelism skills

Ability to define standards

Education

PhD in ML or equivalent depth of expertise

Tools

PyTorch

TensorFlow

AWS

GCP

Job description

Overview

Helsinki – onsite – full-time, permanent

Principal LLM Engineer

Supercell is looking for a hands-on builder with deep expertise in developing production-grade LLM applications, someone who thrives in a collaborative and entrepreneurial environment, and who is excited to define the craft of LLM engineering inside Supercell. Internally, this role is known as LLM Engineer.

About the Role

Supercell AI team drives the company-wide AI agenda and acts as the subject matter expert team for all AI-related topics. Supercell is known for its small teams that can deliver global hit games. We want to equip our employees with the right tools to keep them super efficient and effective in the AI era, and automate internal and player-facing repetitive tasks using agents and bots. We are now preparing for a future where humans and agent team members work seamlessly side by side.

We’re looking for a Principal-level LLM Engineer who not only builds production-grade agentic LLM applications but also takes ownership of the craft of LLM engineering inside Supercell. This is a role for someone who can both set the standard for how we design and deploy LLM-powered systems and act as an internal advocate and trusted advisor — helping our teams imagine what’s possible, sell in the value of new approaches, and build with confidence.

What You’ll Do

• Act as the craft owner for LLM engineering at Supercell — setting direction, sharing best practices, and raising the bar for what “great” looks like in LLM-powered systems.
• Drive adoption of a wide range of LLM and agentic applications (e.g. in-game bots, player support, social insights, internal productivity tools).
• Champion AI development tools as a high-leverage use case — helping teams accelerate workflows, code smarter, and build better systems faster.
• Partner closely with game and functional teams to evangelize LLM capabilities and turn vague opportunities into concrete solutions.
• Serve as a bridge between technical and non-technical stakeholders, clearly communicating strengths, limitations, and business value of different approaches.
• Monitor emerging developments in the LLM and agents space; assess technologies for safety, reliability, and performance; and build our internal stack of recommended approaches.
• Lead the design and implementation of robust evaluation, monitoring, and safety frameworks for production LLM-powered systems.
• Rapidly prototype and deliver production-grade systems — and coach, mentor, and enable other engineers to build confidently themselves.

What We’re Looking For

• Deep expertise in building production-grade LLM and agentic applications — including real-world experience with evaluation, monitoring, and scaling.
• Strong background in LLM applications, with hands-on experience in AI development tools (e.g., code generation, debugging agents, tool-assisted workflows) and a perspective on how they fit into the broader LLM ecosystem.
• Expert-level knowledge of core LLM concepts: RAG, CoT, reasoning models, memory, fine-tuning, tool use, self-correction.
• Strong software engineering skills with the ability to deliver robust, production-ready solutions quickly.
• A craft mindset: ability to define standards, set direction, and raise the bar across a company.
• Excellent communication and evangelism skills — able to sell ideas, influence stakeholders, and build excitement around AI capabilities.
• Comfort working independently as well as in small, fast-moving teams.
• Positive, pragmatic, and collaborative mindset.
• Passion for gaming or experience in the industry is a plus.
• PhD in ML or equivalent depth of expertise preferred.

Relevant technologies and platforms

• Agent technologies: OpenAI Agents & GPTs, Anthropic Agents, MCP, LangGraph, Amazon Bedrock Agents
• ML: PyTorch, TensorFlow, ONNX
• Data: Python, Databricks, Spark
• Cloud: AWS, GCP
• Vector databases: Pinecone, Chroma, pgvector

Benefits and Compensation

We structure our compensation and benefits to serve this purpose and to recognize you as a human being, not a resource. We aim to provide an environment where you can do your best work and enjoy a fulfilling professional life.

About Supercell

We are a games company based in Helsinki, Finland, with offices in San Francisco, Seoul, Shanghai, and London. Since our launch in 2010, we have released seven games globally — Hay Day, Clash of Clans, Boom Beach, Clash Royale, Brawl Stars, Squad Busters, and mo.co. Our mission is to create great games that as many people as possible play for years and that are remembered forever. We achieve this by building the best possible teams and giving them freedom and independence to succeed.

You Might Love It Here...

If you love games, Supercell is the place for you. We are proactive, independent teams with the freedom to do what they think is best for players and the company. We also take care of our people with the compensation, work environment, and resources needed to succeed and have fun.

You Are Not Your Job Title
We don’t emphasize prefixes like senior or principal in internal titles. We focus on doing what’s best for our players. For hiring purposes, industry-standard titles are used, and you may choose a title that fits publicly on LinkedIn.

This position is in Helsinki, but you’re not?
Moving to Helsinki is supported by dedicated guidance to help you and your family, including relocation assistance.

Not sure if you should apply?
We encourage you to apply even if you don’t tick every listed requirement. We’re happy to discuss accommodations for the recruitment process.

And here’s a video about what we do. (Best enjoyed with salmiakki and rye bread)

Interested?

To apply, please submit your details and CV. You can provide a portfolio or other links as applicable. We also collect application data to manage our recruitment activities globally and may store details for future opportunities; you may opt out of future contact.