Senior Full-Stack Engineer - AI Startup (Typescript, Node, React)
London - 4 days per week in the office
Permanent | £120,000 - £150,000
We're working with an exciting early-stage AI startup building an agentic platform for institutional finance.
The company is a small, high-performing team of fewer than 10 people, moving quickly and building towards its next stage of growth and investment.
This is an opportunity for a senior engineer to join at an early stage and play a significant role in shaping both the product and technical direction of the business.
The Role
As a Senior Full-Stack Engineer, you'll act as a key technical contributor within a small engineering team.
You'll work across the entire technology stack - from database and backend development through to the user interface - while taking ownership of the software you build through to production and beyond.
Working closely with the founding/lead engineer and founders, you'll have significant influence over architecture, engineering practices and the way the product evolves as the company scales.
Key Responsibilities
- Build and deliver end-to-end product functionality across the full stack.
- Develop and maintain high-quality production software.
- Work across backend, frontend, database and API development.
- Contribute to technical architecture and engineering decisions.
- Take ownership of features from concept through to production.
- Work closely with founders and engineering leadership to shape the product roadmap.
- Help establish strong engineering standards as the team grows.
- Use modern AI-assisted development tools to accelerate development and productivity.
- Troubleshoot, maintain and continuously improve production systems.
- Contribute to the development of AI-powered and agentic solutions.
What We're Looking For
This is an early-stage hire, so we're looking for someone who brings more than just strong technical ability.
You should be genuinely excited by the opportunity to work in a small team, take ownership and help build something from an early stage.
Essential Experience
- 8+ years' commercial software engineering experience.
- Strong full-stack development experience with no significant frontend or backend bias.
- Recent, hands-on experience with:
- TypeScript
- React
- Node.js
- Proven experience building and maintaining production software.
- Experience taking ownership of projects and features from development through to production.
- Regular use of modern AI coding/development tools, such as Claude Code, Cursor or similar.
- Strong understanding of software engineering principles and architecture.
- Experience working with APIs, cloud platforms and modern software development practices.
Startup Experience
Previous experience working within a startup or early-stage technology business is highly desirable.
We're particularly interested in engineers who have:
- Joined a company at a very early stage.
- Been one of the first 4-5 engineers.
- Worked as a founding engineer or similar.
- Helped take a product from an early stage through meaningful growth.
- Thrived in environments where engineers have significant ownership and responsibility.
Desirable Skills
Experience with some of the following would be highly advantageous:
- Vertex AI
- Large Language Models (LLMs)
- Agentic AI
- Docker
- CI/CD
- Infrastructure as Code
- Microservices
- Event-driven architecture
- AWS
- Google Cloud Platform (GCP)
You don't need to have experience with every technology listed, but a strong interest in modern AI engineering and cloud-native development would be highly beneficial.
Technology Stack
- React
- TypeScript
- Node.js
- AWS
- Google Cloud Platform (GCP)
- Vertex AI
- REST APIs
- Large Language Models (LLMs)
- Agentic AI
- Git
- CI/CD
The Person
- Entrepreneurial and genuinely excited by startup environments.
- Comfortable working with ambiguity and moving quickly.
- Highly motivated and proactive.
- Comfortable taking ownership rather than waiting for detailed instructions.
- Interested in AI and how it is changing software development.
- A strong communicator who enjoys working closely with founders and technical leadership.
- Able to balance speed with producing reliable, maintainable production software.
- Excited by the opportunity to help shape a product and engineering function from an early stage.
What's on Offer?
- £120,000 - £150,000 salary
- Permanent position
- London-based
- 4 days per week in the office
- Opportunity to join a small, high-performing AI startup at an early stage
- Direct exposure to the founding team
- Significant influence over technical direction and architecture
- Opportunity to work with modern AI development tools and technologies
- Genuine ownership and responsibility from day one
If you're a senior full-stack engineer who enjoys building, taking ownership and working in an early-stage AI environment, we'd be keen to hear from you
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