Software Engineer

We're not just building another accounting tool — we're building the first AI-native accounting platform in the Nordics.

Founded by the team behind Weld and early Pleo employees. Backed by top-tier Nordic investors.

We're looking for a full-stack engineer who will be a foundational pillar of our product and engineering culture. We're looking for a pilot, not a passenger — someone driven by building something from scratch.

Accounting software hasn't fundamentally changed in decades. Small businesses in Denmark use expensive, manual solutions that require a bookkeeper — and there aren't many alternatives.

Numina replaces that entire stack. One platform that handles bookkeeping, receipt management, invoicing, and bank reconciliation. AI-native from day one — not a legacy product with a chatbot stapled on.

We're live with paying customers and shipping new features every week.

• Design, build, and ship features end-to-end — from cloud infrastructure to the user-facing web application
• Write clean and maintainable code across our stack: TypeScript, React/Next.js, Node.js (Express), and PostgreSQL
• Build AI-native features — LLM pipelines, embeddings, and agents that are core to the product
• Collaborate closely with founders to translate customer insights into technical solutions
• Define the architecture that supports our growth in complexity and scale
• Establish best practices for testing, deployment, and code reviews
• We use AI coding agents (Cursor, Claude Code) heavily. You should too.

• A problem solver — you enjoy tackling complex technical challenges and finding elegant, practical solutions
• A self-starter — in a startup there's no playbook, you'll help us write it
• A team player — you thrive in a collaborative environment and give and receive constructive feedback
• Strong full-stack skills in TypeScript. React/Next.js on the frontend, Node.js (Express) on the backend
• Solid PostgreSQL knowledge — efficient queries, performance tuning
• Genuine excitement about applied AI. You follow what's happening in the space and have opinions about where it's going
• Experience with AI coding agents (Cursor, Claude Code, etc.) — not just dabbling, but actually shipping faster with them

• Hands-on experience building with LLMs — prompt engineering, RAG pipelines, embeddings, vector databases
• Experience with FinTech, accounting, or B2B SaaS products
• Complex SQL optimization, analytics pipelines
• DevOps with AWS/GCP, Docker, GitHub Actions
• Building design systems or custom UI component libraries

• Ship end-to-end: You own the problem, not just a layer in the stack
• High autonomy: You'll have the context and trust to make big decisions
• Small team, high impact: No bureaucracy, just high-speed and high-quality shipping
• Ship over plan: We try things out instead of endless planning
• AI-augmented engineering: We use the latest AI tools to move faster

• A unique opportunity to shape a product and company from the ground up. Your work will have direct and visible impact every single day
• Close collaboration with experienced founders from the Danish startup scene
• Meaningful equity — you'd be among the first 10 people at the company
• The best tools for the job, including a new MacBook Pro
• Competitive salary and a great office in the heart of Copenhagen
• Hybrid setup (2-4 office days)