Dexis Development

Lead Engineer | Node.js, React Native, AI Agents

Location: London / hybrid preferred, or remote from Central & Eastern Europe
Level: Mid-to-Senior, hands-on Lead
Employment: Full-time, permanent

About the company

We are an early-stage UK product company building an AI-powered platform focused on professional relationships and network intelligence.

The product combines a social graph, relationship data and an AI agent that helps users identify relevant people, understand their network and strengthen important connections.

We are looking for a Lead Engineer / Founding Senior Engineer who will own the technical architecture, write production code and help grow the engineering team.

This is a hands-on engineering role, not a pure management position.

Tech stack

• Node.js / TypeScript / Express
• React Native + Expo
• MongoDB Atlas
• Atlas Vector Search + BM25 / hybrid retrieval
• OpenAI / custom LLM tool-calling agents
• AWS EC2, Cognito, S3
• Docker, Nginx
• GitHub Actions / CI/CD

Responsibilities

• Own technical architecture and production infrastructure
• Ship features across backend, mobile and AI agent layers
• Build and improve LLM agents, prompts, tool-calling flows and evaluation
• Mentor engineers and establish strong engineering practices
• Implement privacy-by-design and GDPR requirements
• Build and use synthetic data for development, testing and model evaluation
• Own CI/CD, monitoring, secrets management and incident response
• Own application and infrastructure security
• Secure AI agents against prompt injection, data leakage and unintended tool actions
• Work directly with the Founder on product and architecture decisions

Must-have

• 4+ years of professional software engineering experience
• Strong Node.js / TypeScript backend experience
• Experience owning real production systems
• Comfortable across backend, frontend/mobile and infrastructure
• MongoDB or similar document database experience
• Hands-on experience building LLM agents and prompting systems
• Experience with agent tool usage and evaluation
• Practical GDPR and data privacy knowledge
• Strong security fundamentals
• Understanding of AI-agent risks such as prompt injection, data leakage and unintended actions
• Experience working with synthetic data
• Production deployment, monitoring and incident-response experience
• Previous mentoring or technical leadership experience
• Comfortable with ambiguity and a fast-moving startup environment

Nice-to-have

• React Native / Expo
• RAG / vector search
• AWS Cognito
• Previous Tech Lead, CTO or founding engineer experience
• Application security / pentesting background
• Experience securing LLM / AI-agent applications

Compensation

Competitive salary + equity depending on experience and location.

We are looking for someone interested in a long-term role and growing together with the company, not a freelance or short-term contract position.

We’re looking for a strong UI/UX Designer with 3+ years of experience who can create intuitive, modern product interfaces and actively use Claude / AI tools in daily work.

You’ll work closely with product managers, developers and stakeholders on web and mobile products, from early ideas and user flows to polished UI and design systems.

Requirements

• 3+ years of UI/UX design experience
• Strong Figma skills
• Solid UX and UI fundamentals
• Experience with Design Systems
• Strong understanding of responsive design
• Experience with user flows, wireframes and prototypes
• Ability to work with product metrics and user feedback
• Strong communication and collaboration skills
• Hands-on experience with Claude and other AI tools
• Ability to use AI for research, ideation, UX analysis and workflow automation

• Strong prompting skills and ability to critically evaluate AI-generated results

   

Nice to have

• Basic HTML/CSS/React knowledge
• Understanding of frontend limitations and implementation
• Graphic design skills
• Experience creating presentations and pitch decks

We’re looking for someone who is product-minded, proactive and comfortable experimenting with new AI-powered design workflows.

Please send your portfolio and briefly describe how you currently use Claude or other AI tools in your design process.