Principal Software Engineer

Principal Platform Engineer at the company

190-260 PLN/H

Hybrid – Kraków or Remote

B2B role

the company powers operations for companies building satellites, fusion reactors, next-generation aircraft, and hypersonic vehicles. Our clients are working on some of the most advanced industrial programs in the world — and they rely on software that can keep up. Companies such as Hermeus, Relativity Space, and Sierra Space use the company to run complex manufacturing operations with greater control, traceability, and speed.

We're a SaaS company with a team that includes former leaders from SpaceX. We move fast, operate globally, and make decisions swiftly - because the people we serve can't afford anything less. Your voice will be heard here, and the work you do will have a real impact on the world.

We are hiring a Principal Software Engineer to help shape the technical future of our platform. This role is for someone who wants to solve hard backend problems, guide architecture with sound judgment, and raise the level of other engineers through mentorship, communication, and strong engineering standards.

The Role

As a Principal Platform Engineer at the company, you'll work at both levels: deep in the hardest problems on the platform, and wide enough to set the standard for others to follow. You'll define the architecture, raise the quality bar, and make sure the right technical decisions are made, not by directing from a distance, but by being the person in the room whose opinion carries weight because the work backs it up. 

This role requires both deep hands-on technical contribution and the ability to multiply the impact of others. We need someone who can take on the hardest problems while also helping senior developers and leads make better technical decisions through teaching, feedback, and clear standards.

You will report directly to the Director of Software Engineering and act as their technical partner across the organization. This is a individual contributor role with no people management responsibilities.

You should be comfortable working in a high-change environment where priorities evolve, new information appears quickly, and strong technical judgment is needed to keep teams moving in the right direction without losing quality.

What you'll do

• Own the architecture and technical direction of the platform’s core 

• Tackle the hardest engineering problems, including performance bottlenecks, complex integrations, and architectural evolution 

• Define and evolve backend engineering standards across all teams 

• Lead design reviews and author RFCs/ADRs for high-impact technical decisions 

• Partner with the Director of Software Engineering, Product, and engineering leadership to assess technical feasibility early, shape direction, and resolve tradeoffs before they become delivery problems 

• Mentor senior engineers code reviews, architecture workshops, pair programming, technical discussions, and tech talks that improve how the organization designs, builds, and operates software 

• Raise the quality bar across the backend through example, teaching, and clear standards
  

Required skills & experience

• 8+ years of backend engineering experience, with deep, proven mastery of C# and modern .NET 

• A demonstrated track record operating successfully in a Staff Engineer, Principal Engineer, or Senior Tech Lead role 

• Proven experience architecting, building, and owning large, complex systems end-to-end, including both monolithic and distributed architectures 

• Expert-level SQL and database design skills, including diagnosing slow queries in production and designing schemas that hold up under real load 

• Deep practical expertise with Entity Framework, including performance tradeoffs, query behavior, and data access strategy 

• Strong architectural judgment and experience applying concepts such as DDD and clean architecture pragmatically 

• A strong quality mindset, including test automation strategy and clear standards for what “done” means 

• Strong written and verbal communication skills in English — you are comfortable explaining technical tradeoffs, mentoring other engineers, leading code reviews, and facilitating architecture discussions 

• Enthusiasm for and hands-on proficiency with AI coding tools such as Cursor and Claude Code as productivity multipliers
  

Nice to have
You'll stand out if you bring any of the following:

• Hands-on experience with cloud infrastructure at scale, with Azure being a strong advantage

• Experience with Angular or a modern frontend framework - enough to make informed architectural decisions across the full stack

• Familiarity with Azure DevOps and CI/CD pipeline design at an organizational level, not just usage

• Experience designing for compliance-driven deployment constraints - data sovereignty, tenant isolation, and schema management across numbers of independent databases

• Background or genuine curiosity about Manufacturing Execution Systems (MES) -understanding the domain makes the hardest problems tractable

Our tech stack

• Backend: .NET, C#, Entity Framework, SQL Server / Azure SQL 

• Messaging: Azure Service Bus, MassTransit 

• Observability: OpenTelemetry, Grafana stack 

• Frontend: Angular, our own Angular Component Library 

• Cloud: Azure 

• CI/CD: Azure DevOps 

• AI tooling: Cursor, Claude Code, and other modern AI-assisted development tools
  

What you’ll get in return

• Real authority, real access. Direct collaboration with the CPO and Director of Development. Your decisions will be heard, debated, and acted on - with organizational backing to make standards stick.

• Customers building the next century. Rockets, fusion reactors, hypersonic systems. The problems you solve here have consequences that matter.

• People who will match you. You'll work alongside engineers and leaders with backgrounds from SpaceX and other high-bar organizations. Expect to be challenged, not just followed.

• AI at the foundation, not the edge. You'll be building the architecture that makes AI native to the platform - not retrofitting it later.

• Hybrid working with three days in our Kraków office, comprehensive healthcare including life insurance, and a Multisport Card.

• This role is for someone serious about their craft. If that is you, we would like to talk.