A career driven by you. At LeasingMarkt.de, we bring customers and dealers together to make car leasing more accessible, transparent, and efficient. With over 1,000 partner dealerships and nearly 2 million users across the DACH region and the Netherlands, we’ve become Germany’s #1 leasing platform. To keep growing and driving innovation in the mobility space, we’re looking for a Senior Software Engineer to join our high-performance team at our Düsseldorf office. 

As a Senior Software Engineer, you will play a key role in designing and developing robust, scalable applications that power one of the largest automotive leasing marketplaces in Europe. You’ll collaborate with a cross-functional team to build and evolve solutions that are architecturally sound, easy to maintain, and built for long-term impact. You’ll help shape technical direction while raising the bar for software quality and stability across the platform. 

What you’ll do:

• Join one of our builders’ teams to build great products loved by our customers. 
• Apply an AI-first mindset to every phase of you-build-it-you-run-it: from design and coding to testing, deployment and operations.
• Work hands-on in real product codebases (for example TypeScript/Node/Next.js or Java/Spring), using GenAI tools to accelerate development, improve quality and simplify existing systems.
• Build and evolve AI-powered internal tools and workflows (assistants for coding, reviews, documentation, testing) that engineers across AutoScout24 can rely on every day.
• Act as a multiplier and culture driver: coach teams on effective GenAI usage, share patterns and anti-patterns, and help establish AI-first ways of working across our engineering organization.
• Experiment, measure and improve: run small, data-informed experiments with teams, learn what works in our context, and turn successful approaches into repeatable standards and playbooks. 

What you’ll bring: 

• Experience leveraging AI and Generative AI (GenAI) to enhance engineering productivity — including code generation, debugging, reviews, documentation, and decision support — with a proactive mindset toward adopting tools that streamline development and drive innovation. 
• Deep, hands-on experience building production systems (we expect you’ve spent at least 5 years doing this, possibly much more), ideally with PHP and Laravel as well as TypeScript/Node.js/Next.js on AWS, Azure or GCP.
• Demonstrated personal excellence in using GenAI coding tools (for example GitHub Copilot, ChatGPT, Claude Code, Cursor, OpenAI Codex) to significantly improve your own development speed and quality: code generation, refactoring, debugging, tests and documentation. 
• Experience integrating LLM APIs (such as OpenAI, Anthropic, Azure OpenAI, Vertex AI or similar) into applications or internal tools.
• Strong communication and influencing skills: you can introduce new tools and practices, align stakeholders, handle skepticism and iterate based on feedback.
• A curious, growth-oriented mindset: you actively seek out new practices and tools, you are comfortable learning in public, and you help others do the same.
• A pragmatic view of GenAI: you understand its limitations and risks and know how to put guardrails in place (reviews, tests, policies) to keep usage safe, compliant and sustainable at scale.
• Experience with performance optimization, caching strategies, and system observability is a plus. 

A culture of growth  

With over 50 nationalities represented, we’re proud to welcome people of all backgrounds to our growing community, and we’re always finding new ways to help people feel welcomed and included. Here, you’ll have the tools, training and support you need to work in a way that suits you, learn new skills and reach your potential.  

For a career where you can drive our business and shape your future, apply now. 

Who we are

Helsing is a defence AI company. Our mission is to protect our democracies. We aim to achieve technological leadership, so that open societies can continue to make sovereign decisions and control their ethical standards. 

As democracies, we believe we have a special responsibility to be thoughtful about the development and deployment of powerful technologies like AI. We take this responsibility seriously. 

We are an ambitious and committed team of engineers, AI specialists and customer-facing programme managers. We are looking for mission-driven people to join our European teams – and apply their skills to solve the most complex and impactful problems. We embrace an open and transparent culture that welcomes healthy debates on the use of technology in defence, its benefits, and its ethical implications. 

The role

Our Autonomous Air System V&V team builds the simulation and validation environments that enable rigorous testing of autonomous air systems before they ever leave the ground. We develop Software-in-the-Loop (SiL) and Hardware-in-the-Loop (HiL) environments that allow engineers to integrate, test, and assure AI-driven capabilities against virtualised and representative hardware.

We build software that is subject to significant and unorthodox technical constraints, must operate in a wide variety of constantly-changing environments, and has to support an ever-growing list of challenging use-cases. What we build ultimately ends up in the hands of real people in high-risk, high-stress situations – from mission planning to command and control (C2) and mission debrief – so must be both reliable and frictionless.

Taken together, this brings a whole host of interesting engineering challenges across a wide variety of fields that you'll help us solve. To give some examples:

• Data visualization (e.g., rendering complex simulation outputs, test results, and AI behavior in human-understandable ways)

• Human-Autonomy Teaming (e.g., UIs for effective human oversight, control, and trust calibration)

• Real-time interfaces (e.g., live test execution dashboards, simulation monitoring, and streaming data displays)

• Complex technical UIs (e.g., making dense, multi-dimensional data accessible to engineers and operators)

• Design systems (e.g., building reusable component libraries that enable rapid, consistent UI development across products)

• Frontend performance (e.g., efficiently rendering large datasets, optimizing real-time updates, and maintaining responsiveness under load)

In several of these areas, we are working near the state-of-the-art; we actively read (and sometimes implement) research papers, and often need to push even further to make theory work in practice. In others, we are applying well-known techniques to real-world situations (with real-world limitations) that have never been used in before, which requires skill, diligence, and honing a deep understanding of the underlying technologies.

The day-to-day

• Review code contributions, proposals, and RFCs from colleagues. At Helsing we strongly believe that unblocking others takes precedence over spending more time on your own work.

• Own the user interface end-to-end, from early wireframes and prototypes through to production-ready code. You'll work closely with product and UX colleagues to shape how engineers interact with our tools.

• Propose and implement new features, capabilities, visualizations, or even full products across our stack. We encourage our engineers to look beyond their immediate team for missed opportunities, and to speak up when they identify one.

• Translate complex technical data into usable, intuitive interfaces. You'll turn raw simulation outputs, test results, and AI behavior data into visualizations that engineers can actually understand and act on.

• Establish and evolve our component library, ensuring consistency, reusability, and alignment with our visual design standards across multiple front-ends.

• Become a mentor, find a mentee, and help support and develop our interviewing pipeline. The people make or break the company, and we want as many engineers as possible to be part of fostering and growing the organisation.

• Share your experience and technical know-how with other Helsingers. We host tech talks, get together for smaller "let's learn together" groups, run topical office hours (e.g., on React, TypeScript), etc. to help each other get better with time.

• Connect with, understand, and make changes to backend systems as needed. Our backends are primarily written in Rust, and you'll need to be comfortable navigating unfamiliar codebases to unblock yourself and improve integrations.

• Further develop our tests and benchmarks, both at the micro and macro level. We operate in a domain where robustness is of the utmost importance, and an extensive and ever-improving test suite is key to achieving that.

• Present your work at our weekly demo sessions. We want engineers to come together around what they are working on and to feel like they are not endlessly squirrelling away at something that doesn't matter. To that end, we host (and actively work towards) demo sessions that allow early feedback, celebration of progress, and a better shared understanding of everything that goes on at Helsing.

You should apply if you

• Have strong frontend design and coding experience with JavaScript.

• Have state-of-the-art experience with frameworks like React.

• Enjoy designing for technical products and data-heavy UIs, and have strong user research and prototyping skills.

• Are experienced with APIs and server-client communication like REST and GraphQL.

• Are comfortable working with unfamiliar backends, ideally with some exposure to languages like Rust.

• Can write legible, maintainable, and performant code.

• Communicate well in English, both verbally and in writing.

• Enjoy collaborating with others, including reviewing code and pair programming.

• Are comfortable working asynchronously (writing PRs and RFCs, having discussions by email).

• Strive to improve yourself, your peers, and the culture you work in over time.

• Feel like ethical considerations are an inherent part of engineering.

Note: We operate at an intersection where women, as well as other minority groups, are systematically under-represented. We encourage you to apply even if you don’t meet all the listed qualifications; ability and impact cannot be summarised in a few bullet points.

Nice to have

• Significant recent experience with React.

• Working knowledge of Next.js/SSR and its strengths and weaknesses.

• Established understanding of modern JS bundlers, such as Vite.

• Experience with styling utility-class libraries such as TailwindCSS.

• Data visualization expertise (e.g., D3.js, custom charting, or complex dashboard design).

• Background in designing software for aerospace, defense, or AI end users.

• Experience with simulation, model monitoring, or developer tools.

Join Helsing and work with world-leading experts in their fields

• Helsing’s work is important. You’ll be directly contributing to the protection of democratic countries while balancing both ethical and geopolitical concerns. 

• The work is unique. We operate in a domain that has highly unusual technical requirements and constraints, and where robustness, safety, and ethical considerations are vital. You will face unique Engineering and AI challenges that make a meaningful impact in the world. 

• Our work frequently takes us right up to the state of the art in technical innovation, be it reinforcement learning, distributed systems, generative AI, or deployment infrastructure. The defence industry is entering the most exciting phase of the technological development curve. Advances in our field of world are not incremental: Helsing is part of, and often leading, historic leaps forward. 

• In our domain, success is a matter of order-of-magnitude improvements and novel capabilities. This means we take bets, aim high, and focus on big opportunities. Despite being a relatively young company, Helsing has already been selected for multiple significant government contracts.  

• We actively encourage healthy, proactive, and diverse debate internally about what we do and how we choose to do it. Teams and individual engineers are trusted (and encouraged) to practise responsible autonomy and critical thinking, and to focus on outcomes, not conformity. At Helsing you will have a say in how we (and you!) work, the opportunity to engage on what does and doesn’t work, and to take ownership of aspects of our culture that you care deeply about. 

What we offer

• A focus on outcomes, not time-tracking

• Competitive compensation and VSOP options

• Relocation support

• Social and education allowances

• Regular company events and all-hands to bring together employees as one team across Europe
  
  

Helsing is an equal opportunities employer. We are committed to equal employment opportunity regardless of race, religion, sexual orientation, age, marital status, disability or gender identity. Please do not submit personal data revealing racial or ethnic origin, political opinions, religious or philosophical beliefs, trade union membership, data concerning your health, or data concerning your sexual orientation.

A career driven by you. Join AutoScout24 Group and experience life in the fast lane. We’re not just leading the market; we’re creating it. For a career that doesn’t stand still, where you can put your ideas in the driving seat and change the way the world moves, join our global community. 

We’re hiring a strong Software Engineer / AI Enabler to multiply the impact of our Product & Technology organization. This role is for someone who is excited about GenAI’s boosting their own engineering performance and productivity and now wants to influence a large, ambitious organization—raising the bar for how software is delivered in a complex, established and market-leading business, not a greenfield startup. 

The engineering world is moving very fast. We are all learning every day. Your core traits should be curiosity and a strong drive to learn and grow. We do not expect you to know everything. We expect you to help accelerate our curiosity and learning culture, and to become AI-first together with us. 

What you’ll do 

• Join one of our builders’ teams to build great products loved by our customers.
• Apply an AI-first mindset to every phase of you-build-it-you-run-it: from design and coding to testing, deployment and operations.
• Work hands-on in real product codebases (for example TypeScript/Node/Next.js or Java/Spring), using GenAI tools to accelerate development, improve quality and simplify existing systems.
• Build and evolve AI-powered internal tools and workflows (assistants for coding, reviews, documentation, testing) that engineers across AutoScout24 can rely on every day.
• Act as a multiplier and culture driver: coach teams on effective GenAI usage, share patterns and anti-patterns, and help establish AI-first ways of working across our engineering organization.
• Experiment, measure and improve: run small, data-informed experiments with teams, learn what works in our context, and turn successful approaches into repeatable standards and playbooks. 

What you need to succeed 

• Deep, hands-on experience building production systems (we expect you’ve spent at least 5 years doing this, possibly much more), ideally with TypeScript/Node.js/Next.js or Java/Spring Boot on AWS, Azure or GCP.
• Proven experience working in large, existing codebases and delivering well-tested, maintainable features in web or backend services.
• Demonstrated personal excellence in using GenAI coding tools (for example GitHub Copilot, ChatGPT, Cursor, OpenAI Codex) to significantly improve your own development speed and quality: code generation, refactoring, debugging, tests and documentation.
• Experience integrating LLM APIs (such as OpenAI, Anthropic, Azure OpenAI, Vertex AI or similar) into applications or internal tools.
• Strong communication and influencing skills: you can introduce new tools and practices, align stakeholders, handle skepticism and iterate based on feedback.
• A curious, growth-oriented mindset: you actively seek out new practices and tools, you are comfortable learning in public, and you help others do the same.
• A pragmatic view of GenAI: you understand its limitations and risks and know how to put guardrails in place (reviews, tests, policies) to keep usage safe, compliant and sustainable at scale. 

With over 50 nationalities represented, we’re proud to welcome people of all backgrounds to our growing community. Here, you’ll have the tools, training and support you need to work in a way that suits you, learn new skills and reach your potential. 

For a career where you can drive our business and shape your future, apply now.