Back End Developer - Zurich

About ZEVEN · We're building Athletic Intelligence—AI that helps ambitious athletes perform better. · Founded in March 2025 in Zurich, Switzerland, ZEVEN is creating Lucy: an AI Companion built on a Domain Language Model for sports. Lucy can think, optimize, hyper-personalize, an ...

Jobbeschreibung

About ZEVEN

We're building Athletic Intelligence—AI that helps ambitious athletes perform better.

Founded in March 2025 in Zurich, Switzerland, ZEVEN is creating Lucy: an AI Companion built on a Domain Language Model for sports. Lucy can think, optimize, hyper-personalize, and do—because nothing is canned.

Our co-founders: Fahri built two unicorns from ground up as founder and CEO (Qtera $3.25B exit, Plume $2.6B) and raised $750M+. Alex is an AI/ML expert and former U23 competitive cyclist. We work with world-class advisors including one of the all-time best cyclists in the world today. We're already generating revenue.

The role

We are seeking an experienced Senior Backend Engineer to join our on-site team in Zurich, Switzerland. The successful candidate will be responsible for designing, developing, and maintaining scalable and efficient backend systems for our web applications. This is a hands-on, high impact role that requires strong technical expertise, problem-solving skills, and the ability to work collaboratively across different domains.

Key responsibilities

• Lead and shape the backend architecture of our brand new platform.
• Design and implement REST APIs.
• Implement key application functionality involving maps, relational databases (PostgreSQL).
• Design and implementation of infrastructure (we use AWS and SST).
• Integrate backend systems with third-party services, such as authentication providers, payment gateways, and messaging queues.
• Optimize backend system performance, scalability, and reliability to ensure high uptime and responsiveness.
• Work closely with engineering and product to ensure seamless integration and deployment of backend systems.

Requirements

Experience:

• 5+ years of experience in backend engineering, with a focus on web application development.

Criteria:

• Must be eligible to work in Switzerland without visa sponsorship.

Technical Skills:

• Proficiency in one or more backend programming languages, such as TypeScript, JavaScript or Python.
• Knowledge of relational database management systems (e.g. PostgreSQL).
• Experience with RESTful API design and development.
• Good command of DevOps practices, including continuous integration and deployment (CI/CD).

Nice to Have:

• Experience working with cloud-based infrastructure (preferably AWS), including serverless computing (e.g. AWS Lambda) and high-performance clusters (GPUs).
• Exposure to highly scalable web applications with a large user-base.
• Familiarity with machine learning frameworks and tools, such as Large Language Model APIs.

Our tech stack

• TypeScript for web + Bun), Python for ML.
• PostgreSQL (w/ PostGIS).
• React + TanStack.
• AWS, SST, GitHub Actions.

Among other tools, we use Slack, Google Suite, Zoom, Notion, GitHub (incl. Copilot), and Excalidraw.

Prior experience with every piece of our Tech Stack is not necessary, but willingness to learn is essential.

Why ZEVEN

• Hard Problems
  : Domain LLM for sports, agentic systems with multi-agent orchestration, real-time inference, persistent memory, human-in-the-loop workflows.
• Proven Team
  : Co-founders created $5.85B in shareholder value, raised $750M+, led ambitious AI projects. AI/ML experts in massive-scale systems. Former pro and competitive cyclists. Silicon Valley innovation + Swiss delivery and quality.
• Switzerland Advantages
  : No capital gains tax on equity. Tier-1 AI hub (Google, DeepMind, Anthropic, Meta AI, OpenAI, Apple, Microsoft, AWS, ETH AI Center). Alps, lakes, quality of life.
• High Impact
  : Small team, AI-native from day one, already generating revenue, build for millions globally.

Who you are

• Active:
  You train with goals and understand the challenges we're solving.
• Fast:
  Tremendous sense of urgency, you ship. Startup pace energizes you.
• Problem Solver:
  Analytical, independent thinker, create the path when unclear.
• Clear Communicator:
  Fluent in English, excellent collaborator.
• High Ownership:
  Your Do:Say Ratio is very high. You don't wait. You build, ship, iterate.

What we offer

• Financial:
  Competitive salary, generous equity (no capital gains tax in Switzerland).
• Culture:
  Work-life harmony. Passionate multilingual team. Charming Lake Zurich office. Top equipment. We like to cook together.
• Growth:
  Work directly with and learn from founders and team. Shape product direction from day one.
• Location:
  Zurich, Switzerland - on-site preferred. Remote considered for exceptional candidates. Must be in Switzerland or willing to relocate.

How to apply

Apply directly in our career page: Jobs at ZEVEN.

Include:

1. Your CV/Resume.
2. Brief cover letter explaining: why you're interested in ZEVEN, a significant risk you've taken (professional or personal) and what you learned, your most relevant experience for this role, if you have athletic pursuits, what you're training for.
3. Links to work (GitHub, publications, portfolio, projects).

Process:

1. Initial Review.
2. First Conversation - Discuss backgrounds, desires, mission, goals, overlap.
3. Technical Assessment.
4. Team Interviews.
5. Offer - We move quickly (3-5 weeks total).

Questions? Email us at - we respond to every serious inquiry.