At a Glance
- Tasks: Lead the development of AI-native applications with a focus on full-stack engineering.
- Company: Join a forward-thinking tech company at the forefront of AI innovation.
- Benefits: Enjoy competitive pay, flexible work options, and opportunities for professional growth.
- Other info: Be part of a diverse team that values collaboration and creativity.
- Why this job: Shape the future of AI technology while working on exciting, impactful projects.
- Qualifications: 5-8 years in full-stack development with expertise in React, TypeScript, and backend systems.
The predicted salary is between 70000 - 90000 £ per year.
As a Senior Full-Stack Engineer (3D), you will be a lead contributor in building the next generation of AI-native applications. You sit at the intersection of robust backend orchestration and intuitive frontend design. Your primary mission is to design and implement 'agentic' workflows/harnesses/systems where AI doesn't just respond to prompts but proactively executes tasks, manages state, and interacts with external tools to solve complex user problems.
You will work across the entire stack, leveraging best in class frameworks and tooling for both frontend, data storage, runtime and API design. You will work closely with the UX Research team to understand and develop new interfaces and interaction techniques.
Responsibilities
- End-to-End Engineering: Lead the development of full-stack features, from database schema design to high-fidelity UI implementation.
- Agentic Workflow Orchestration: Design and implement backend logic that allows AI agents to interact with APIs, databases, and long-running processes autonomously.
- Agentic UX Design: Build 'Human-in-the-loop' interfaces that allow users to monitor, steer, and collaborate with AI agents in real-time.
- Infrastructure & Security: Architect secure and performant backend systems using best practices and design patterns, to support high-concurrency AI operations.
- State Management: Manage complex, asynchronous application states where data may be updated concurrently by both users and background AI agents.
- Performance Optimization: Build efficient applications and services, understand how to best to maximize both perceived and actual user experience. Optimize the entire request-response lifecycle, focusing on minimizing latency in LLM streaming and database queries.
- Technical Health: Maintain high standards for code quality, focusing on static type safety, clean architectural consistency and comprehensive unit and integration testing.
Minimum Qualifications
- Experience: Typically 5–8 years of professional full-stack software engineering experience.
- Frontend Stack: Deep expertise in React, TypeScript, and modern CSS/HTML. Ability to build complex, data-rich applications.
- Backend Stack: Proven experience with RDBs (e.g. PostgreSQL) and Object Stores (e.g. s3).
- API Design: Strong experience designing and consuming RESTful and/or GraphQL APIs with a focus on reliability and security.
- AI Development Tooling: Expert-level proficiency with modern agentic development environments (e.g., Cursor, Claude Code, Windsurf) to accelerate the shipping cycle.
- Architecture: Solid understanding of distributed systems, serverless architectures, and relational database modeling.
- Deployment: Familiarity with CI/CD practices and tools (e.g. Jenkins) and cloud providers for compute/network (e.g. AWS ALBs/ECS).
- Communication: Ability to bridge the gap between technical LLM capabilities and practical, user-facing product features.
Preferred Qualifications
- Agentic Frameworks: Hands-on experience with agentic orchestration frameworks (e.g., LangChain, LangGraph, CrewAI, or PydanticAI).
- AI UX Patterns: Deep understanding of 'Agentic UX' patterns, such as ReAct, streaming UI updates, generative UI, and proactive notifications.
- LLM Observability: Experience with monitoring and evaluation tools for AI agents (e.g., LangSmith, Braintrust, or Helicone) to track agent reliability and cost.
- Tool-Calling Expertise: Proven track record of building 'Tools/Functions' for LLMs to interact with third-party SaaS platforms or internal databases.
- Durable Runtimes: Hands-on experience with durable runtime frameworks such as temporal or similar.
- Storage: Experience with Supabase e.g. Row Level Security (RLS), and database migrations.
- Vector Databases: Familiarity with pgvector or other vector stores for RAG workflows.
- Real-time Systems: Experience with WebSockets or Supabase Realtime to provide instant feedback for long-running agentic tasks.
Diversity & Belonging: We take pride in cultivating a culture of belonging where everyone can thrive.
Senior Full-Stack Engineer (3D) in London employer: Merantix
As a Senior Full-Stack Engineer (3D) at our innovative company, you will be part of a dynamic team dedicated to pushing the boundaries of AI-native applications. We foster a collaborative work culture that prioritises employee growth through continuous learning opportunities and cutting-edge projects, all while offering competitive benefits and a supportive environment in a vibrant location. Join us to make a meaningful impact in the tech landscape and advance your career in an exciting field.
StudySmarter Expert Advice🤫
We think this is how you could land Senior Full-Stack Engineer (3D) in London
✨Tip Number 1
Network like a pro! Reach out to your connections in the tech world, especially those who work in AI or full-stack development. Attend meetups or webinars to meet potential employers and get your name out there.
✨Tip Number 2
Show off your skills! Create a portfolio showcasing your projects, especially those involving AI-native applications. This is your chance to demonstrate your expertise in both frontend and backend development.
✨Tip Number 3
Prepare for interviews by brushing up on your technical knowledge and problem-solving skills. Practice coding challenges and be ready to discuss your past projects in detail, focusing on how you tackled complex user problems.
✨Tip Number 4
Don’t forget to apply through our website! It’s the best way to ensure your application gets noticed. Plus, we love seeing candidates who are proactive about their job search.
We think you need these skills to ace Senior Full-Stack Engineer (3D) in London
Some tips for your application 🫡
Show Off Your Skills:When you're writing your application, make sure to highlight your experience with full-stack development. We want to see how you've tackled complex projects, especially those involving AI and user interaction. Don't hold back on showcasing your expertise in React, TypeScript, and backend systems!
Tailor Your Application:Make your application stand out by tailoring it to our job description. Use the same language we do and connect your past experiences to the responsibilities listed. This shows us that you understand what we're looking for and how you can contribute to our team.
Be Clear and Concise:We appreciate clarity! Keep your application straightforward and to the point. Avoid jargon unless it's relevant, and make sure your key achievements are easy to spot. A well-structured application helps us see your potential quickly.
Apply Through Our Website:Don't forget to apply through our website! It’s the best way for us to receive your application and ensures you’re considered for the role. Plus, it gives you a chance to explore more about our culture and values while you’re at it.
How to prepare for a job interview at Merantix
✨Know Your Tech Stack Inside Out
Make sure you’re well-versed in the technologies mentioned in the job description, especially React, TypeScript, and PostgreSQL. Brush up on your knowledge of API design and agentic frameworks, as these will likely come up during technical discussions.
✨Showcase Your Problem-Solving Skills
Prepare to discuss specific examples where you've designed and implemented complex workflows or systems. Highlight how you’ve tackled challenges in state management or performance optimisation, as this will demonstrate your ability to handle the responsibilities of the role.
✨Understand the User Experience
Since the role involves working closely with UX Research, be ready to talk about how you approach user-centric design. Share any experiences where you’ve built interfaces that enhance user interaction with AI agents, showcasing your understanding of 'Human-in-the-loop' concepts.
✨Ask Insightful Questions
Prepare thoughtful questions about the company’s approach to AI development and their vision for agentic applications. This not only shows your interest but also helps you gauge if the company culture aligns with your values, especially regarding diversity and belonging.
