Senior Fullstack Engineer

Neurons, are revolutionizing how brands understand and engage with people. By combining state-of-the-art AI with deep neuroscience insights, Neurons enables companies to predict consumer responses in seconds, transforming marketing into something truly predictive and actionable.

We looking for a Senior Full Stack Engineer to help push this mission forward. This isn’t a role about ticking boxes; it’s about building systems that scale, shipping products that deliver impact, and raising the engineering bar as the company grows. You’ll join the Product and Engineering team and become part of a vibrant, growing organization that prides itself on delivering high-quality products that customers highly value.

If you’re passionate about designing great technology and seeing it make a difference in the real world, this role offers a strong opportunity to thrive.

How Neurons Works

At Neurons, success comes from empowered engineers to solve customer problems directly. They continuously optimize team structure and processes to support this mindset.

Their SDLC evolves constantly. Rather than following a rigid framework, Neurons adopts what works in the current situation and discards what doesn’t.

They follow the core tenets of Shape Up, giving engineers the context and focus to achieve ambitious goals in 6-week cycles. For each cycle, small teams (2–3 engineers) form to tackle specific features or problems.

Each cycle is followed by a 2–3 week cooldown focused on technical debt, bugs, and platform enhancements, ensuring a healthy balance between new features and long-term stability.

What You’ll Be Driving

Design & Scale the Core Platform

You’ll architect and build backend services that power Neurons’ predictive insights, ensuring they are fast, secure, and highly scalable. Your work will enable the platform to process increasing data volumes and deliver real-time results as the company grows.

What helps you succeed: Deep experience with Python (ideally Django or FastAPI), designing distributed systems, and implementing asynchronous processing or microservices.

Deliver Features That Matter – Fast

You’ll work closely with product and design to translate ambitious ideas into working software, building everything from backend logic to frontend interfaces. Your ability to deliver end-to-end functionality will allow Neurons to release new capabilities quickly and confidently.

What helps you succeed: Strong skills in TypeScript and React, plus experience delivering full-stack features from concept to deployment.

Ensure Reliability, Quality, and Clean Code

You’ll drive engineering excellence through clean, maintainable code, robust testing practices, and thoughtful architecture. Every release should strengthen the platform and make it easier to evolve over time.

What helps you succeed: A track record of building reliable systems with strong testing strategies (unit, integration, end-to-end) and familiarity with principles such as SOLID, TDD, or BDD.

Shape Product Direction With Your Expertise

As a senior engineer, you’ll collaborate closely with cross-functional teams to shape technical decisions and influence the product roadmap. You’ll balance ideal architecture with practical business needs, always aiming to deliver maximum impact.

What helps you succeed: Experience with product planning, breaking down complex problems into concrete steps, writing ADRs/RFCs, and aligning technical work with business goals.

Mentor and Multiply Your Impact

You’ll help build a strong, collaborative engineering culture by mentoring junior developers, leading by example in code reviews, and sharing best practices.

What helps you succeed: Comfort leading technical discussions, guiding peers, and raising the bar for engineering quality.

What Success Looks Like

• Products and data pipelines scale smoothly to meet growing demand.

• You help deliver customer value through new features and enhancements to existing functionality.

• Codebases become cleaner, more maintainable, and easier to extend.

• Engineering choices directly shape and accelerate the product roadmap.

• Your technical leadership strengthens the entire team.

The Experience That Helps You Succeed

While there’s no single “perfect” background, Neurons expects the ideal candidate to bring most of the following:

• ~5+ years of professional experience building and scaling web applications

• Proven expertise with Python (Django or FastAPI)

• Strong skills in TypeScript, React, and modern frontend architecture (React Query is a plus)

• Hands-on experience with distributed systems, asynchronous programming, domain-driven design, and event-driven architecture

• A history of delivering robust testing strategies and maintaining production-grade codebases

• Strong communication skills and a collaborative mindset; comfort working in cross-functional, Agile teams

• A curious mindset, with a strong interest in learning and understanding client problems in order to deliver value

Shape What’s Next at Neurons

• Work on technology that merges AI, neuroscience, and marketing—solving problems few others are tackling

• Tackle complex engineering challenges with a team that values creativity, collaboration, and craftsmanship

• See your work deliver measurable impact for some of the world’s biggest brands

Location: This role is based at Neurons’ headquarters in the Greater Copenhagen Area. (Fully remote work is not supported for this position.)

Join the Neurons Movement

Neurons fosters an inclusive culture where innovation flourishes. The company believes true progress comes from being yourself, sharing ideas freely, and collaborating with inspiring colleagues.

Innovation at the Core: With an 11-year legacy founded by neuroscientist and bestselling author Dr. Thomas Zoëga Ramsøy, Neurons continues to push boundaries through data, AI, and applied neuroscience.

Team Spirit and Culture: Collaboration, personal growth, and strong teamwork are central to building something extraordinary.

Results with Empathy: Neurons balances ambition with empathy, encouraging continuous feedback and measuring success not only in results, but also in relationships and positive impact.

Diverse and Inclusive: With 85 employees from 30 nations, Neurons celebrates diversity and is committed to creating a welcoming environment for all backgrounds.

At Neurons, the journey is as exciting as the destination—offering a career where innovation, teamwork, and meaningful results come together.

Benefits

Neurons prioritizes employee health and well-being with initiatives such as yoga, healthy breaks, and mental health resources. Social connection is equally important, with Friday Hygge activities ranging from karaoke and bingo to video games and board games.

Additional benefits include:

• In-house lunch

• Pension plan

• Private health insurance

• Parental leave benefits

• Quarterly company events

• Team events

Want to know more?

Kold+Partners facilitate this recruitment. For questions or additional information, please contact Peter Kold at peter@koldpartners.com/+45 2989 0903.