Job Description

Your mission

Join our team and build the intelligent systems at the core of Cosuno's platform.

• Generative AI: Build and improve our LLM-powered systems that navigate the complex, often messy tendering workflow.
• Ship end-to-end into the product: Own features from model/agent through API to the TypeScript front-end — backend service, API, and the integration into the web app.
• Collaborate across teams: Work with Product, Engineering, and Data to translate business problems into shipped AI features.
• Maintain production AI: Monitoring, alerting, and continuous improvement of everything we deploy.

Your profile

• TypeScript, React, Node: Non-negotiable. You're comfortable shipping into our web app end-to-end — front-end, backend service, API.
• Strong Python: You have 5+ years writing production-grade Python. You write clean, well-structured code.
• End-to-end product delivery: You've shipped AI-powered features into a production web app and owned the integration from research code to real users.
• LLM application depth: You have deep hands-on experience building and deploying LLM/agent systems — RAG, tool use, multi-step reasoning, evals.
• Backend engineering skills: You design APIs, data pipelines, and services.
• Product mindset: You're comfortable with ambiguity and can judge when something is good enough to ship.
• Sharp problem solver: You look at a complex system, quickly identify what matters, and decide what to do next.
• Bias for action: When you're unsure something will work, your instinct is to find out with data rather than keep wondering.

How We Build: Our Engineering Culture

We believe in a calm, collaborative, and productive engineering environment. We trust our engineers and give them the autonomy to do their best work. Our approach includes:

• Agile & Fast-Paced: We practice trunk-based development with daily releases to get value into our users' hands quickly.
• Quality by Default: We maintain a comprehensive Cypress E2E test suite and enforce strict typing, linting, and formatting rules to keep our codebase clean and maintainable.
• DevOps Mindset: Our well-oiled CI/CD pipeline deploys to AWS via Kubernetes, with our entire infrastructure managed as code using Terraform.
• Collaboration & Transparency: We value open discussion, constructive code reviews, and a culture where the best idea wins, regardless of who it comes from.

Why us?

• Competitive Compensation: A competitive salary above the market average.
• Work-Life Balance: Choose to work 100% remotely or from our modern office in Berlin. We offer flexible working hours to fit your life.
• Top-Notch Equipment: A new MacBook Pro to ensure you have the best tools for the job.
• A Great Team: Regular company off-sites and team events that connect us as people, not just colleagues.
• Job Security: A permanent contract in a stable, well-funded company.

About us

Cosuno – Revolutionizing construction through technology.

We are Cosuno – a fast-growing tech startup that is making the construction industry more efficient and transparent with our digital platform for tenders and procurement processes. Our goal: to solve the most complex challenges in the industry with innovation and simplicity.

Why Cosuno?

Artificial intelligence is the key to our solution: it analyzes millions of price data points and helps construction companies create precise and efficient bids. This not only saves our customers time but also helps them avoid unnecessary costs.

But for us, it's not just about technology – it's about the people who drive it. At Cosuno, you will work with creative minds who are reshaping the construction industry. We believe in diversity because we know that the best ideas come from different perspectives. An integrative and inclusive work environment is a matter of course for us.

Join us – Build the future of construction.