Senior Founding Engineer
Nexa Legal
Antwerp, Belgium
5 days ago
Role details
Contract type
Permanent contract Employment type
Full-time (> 32 hours) Working hours
Regular working hours Languages
English Experience level
SeniorJob location
Antwerp, Belgium
Tech stack
.NET
API
Artificial Intelligence
Azure
Continuous Integration
Product Management
Next.js
TypeScript
Google Cloud Platform
Tailwind
React
Large Language Models
Prompt Engineering
Backend
Kubernetes
Front End Software Development
Job description
- You'll be our first engineering hire.
- This is not a "join a team" role.
- This is a build the foundation role.
You will:
- Work directly with the CTO
- Shape architecture and technical direction
- Define how we build, ship, and scale
If you want ownership, this is it.
What makes this interesting
- Real users, real constraints (privacy, correctness, legal impact)
- AI that needs to be right, not just "good enough"
- A system combining: LLM orchestration, structured workflows and evaluation layers
This is not prompt engineering.
This is AI product engineering at depth.
What you'll do
- Build core product capabilities end-to-end (API UI infra)
-
- *Design and implement robust RAG pipelines
- Create evaluation frameworks (offline + online) and quality gates
- Develop durable workflows (Temporal or equivalent)
- Run and improve Kubernetes-based deployments
- Integrate multiple model providers with fallback logic
- Define engineering standards (PRs, releases, testing, docs)
Requirements
- Ship production features independently
- Take ownership of decisions and outcomes
- Have strong experience with .NET and modern TypeScript/React
- Understand (or want to go deep into) LLM systems (RAG, evals, grounding)
- Are comfortable with infrastructure (Kubernetes, CI/CD, environments)
- Communicate clearly and move fast
Not a fit if
- You need detailed specs before starting
- You prefer large teams and clearly defined roles
- You're not comfortable owning infra and product together
- You want to experiment rather than build production systems
Tech stack
- Backend: .NET
- Frontend: Next.js, TailwindCSS
- Workflows: Temporal
- AI/Cloud: GCP (Gemini, Vertex), Azure OpenAI
- Infra: Kubernetes, Helm, Scaleway
Benefits & conditions
- Founding-level impact on product and engineering culture
- Direct collaboration with the CTO
- Real ownership from day one
- Competitive compensation (salary + upside potential depending on profile)
- Flexible setup, with Antwerp as home base
Apply Send:
- GitHub / portfolio (or 2-3 projects you're proud of)
- Short note: why this role fits you
- (Optional) example of how you used AI tools responsibly in production