Senior Full Stack Engineer

Overview

TensorX is a sovereign AI infrastructure platform headquartered in Dublin. We run frontier open-weight large language models on our own NVIDIA Blackwell GPUs in European datacentres, under EU jurisdiction. Customers reach them through a drop-in OpenAI-compatible API. Nothing they send is retained after the request completes. We serve regulated enterprises in finance, healthcare and government as well as developers and AI platforms. We help them adopt AI without compromising on data privacy, compliance or performance.

We are looking for Full-Stack Engineers at various levels to join our growing engineering team. You will take ownership of features across the entire product surface, from our customer-facing dashboard and billing systems through to our backend API services and infrastructure tooling. This is a hands-on, high-impact role in a fast-moving scaleup where your work will directly shape the platform our customers rely on.

You will work across multiple projects, primarily in TypeScript, spanning a React/Next.js frontend and a Node.js/Express API layer backed by PostgreSQL and Redis/Valkey. Frontend development is a key part of this role, and you will be responsible for building the interfaces our customers and their agents interact with daily. We are an AI-native team. Tools such as Claude Code and Codex are part of our daily workflow and materially accelerate how we build and operate systems. We value engineers who can deliver polished, accessible user experiences while also contributing to robust backend services.

Responsibilities

• Feature Delivery - Design, build and ship end-to-end features spanning the frontend dashboard, REST API and database layers, taking work from specification through to production deployment.

• Frontend Development - Build responsive, accessible and performant interfaces using React and Next.js with server-side rendering, middleware and modern routing patterns. Implement design systems using headless component primitives and utility-first CSS.

• Backend & API Development - Develop and maintain RESTful API services in Node.js/Express with full TypeScript type safety. Design relational database schemas and write performant SQL. Implement caching, rate limiting and background job processing.

• Testing & Reliability - Write and maintain automated tests across the stack, including unit, integration and end-to-end tests. Champion testing best practices and help build a culture of confidence in deployments.

• Authentication & Security - Own and evolve our authentication and authorisation systems, including JWT-based auth flows, role-based access control and security hardening throughout the platform.

• Payments & Integrations - Build and maintain third-party integrations including payment processing, cryptocurrency payment flows, transactional email, bot protection and customer messaging.

• Infrastructure & DevOps - Manage containerised development and deployment workflows using Docker within a cloud-native environment. Maintain CI/CD pipelines and contribute to platform reliability.

• Code Quality & Collaboration - Participate in code reviews, contribute to architectural decisions and help establish best practices. Share knowledge and support your teammates across the engineering team.

Skills & Experience

• 5+ years of professional experience building full-stack web applications

• Advanced proficiency in TypeScript across frontend and backend codebases

• Strong frontend skills with React and Next.js (SSR, App Router, middleware), headless component libraries (e.g. Radix UI, shadcn/ui) and utility-first CSS frameworks

• Solid backend experience with Node.js, Express, PostgreSQL (schema design, raw SQL) and Redis/Valkey

• Practical experience with authentication systems, role-based access control and web security practices

• Familiarity with payment platform integration (e.g. Stripe). Experience with cryptocurrency payment protocols is desirable

• Experience with Docker and containerised deployment workflows

• Comfortable using AI-assisted development tools (e.g. Claude Code, Codex) as part of your daily workflow

• A clear and concise communicator who thrives in ambiguity and can articulate technical decisions to both technical and non-technical audiences

Nice to Have

• Experience working with large language models, including areas such as prompt engineering, context engineering, fine-tuning, RAG, evaluation and model deployment

• Experience with AWS and related services (e.g. EC2, ECS, S3, Lambda, CloudFront)

• Exposure to Python and Golang

Education & Qualifications

• BSc/MSc in Computer Science, Software Engineering or a related technical discipline OR equivalent practical experience

Remuneration

• Highly competitive package, dependent on experience

• 25 days paid annual leave

• Hybrid working from our centrally located Dublin office

• Free inference tokens!

  ******* NO AGENCY ASSISTANCE REQUIRED *******