Senior Full Stack Software Engineer | AI Startup

55 Exec Search; Greater London; Hybrid; GBP 90,000 - 130,000; Full time

Benefits offered by this job

Hybrid working with flexibility

Small engineering team

Job summary

55 Exec Search is recruiting a Senior Full Stack Software Engineer for a London-based AI startup. You will help build the production systems behind a next-generation authentication product, working across frontend and backend in a hybrid London office.

You’ll design scalable backend services, APIs, and cloud-native systems on AWS, running Kubernetes workloads and delivering web applications. Collaborate with AI engineers and own architectural decisions from day one.

Qualifications

• Commercial software engineering (5+ years)
• TypeScript and Node.js
• Cloud-native applications
• Building production software
• Designing scalable APIs
• Modern software architecture

Responsibilities

• Build production systems across the full stack
• Design APIs that support AI-powered features
• Develop cloud-native systems on AWS
• Run highly available Kubernetes workloads
• Build intuitive web applications
• Collaborate with AI Engineers on architecture decisions

Skills

TypeScript

Node.js

React

REST APIs

CI/CD

Kubernetes

AWS

Tools

AWS

Docker

Kubernetes

Job description

Senior Full Stack Software Engineer | AI Startup

London | Hybrid (2–3 days per week with flexibility)

Our client is hiring a Senior Software Engineer to help build the software platform behind a next-generation AI authentication product that's changing how people securely interact with technology.

The AI doesn't rely on passwords, fingerprints or facial recognition. Instead, it learns how people naturally interact with their devices to create seamless, continuous authentication.

You'll build the production systems that make this possible.

What makes this different?

You'll solve the engineering challenges that turn cutting-edge AI into a product customers trust:

• Building scalable backend services
• Designing APIs that support AI-powered features
• Developing cloud-native systems on AWS
• Running highly available Kubernetes workloads
• Building intuitive web applications
• Making AI reliable, observable and production-ready

You'll work directly alongside AI Engineers, influencing architecture and making technical decisions from day one.

Why engineers join startups like this

Large companies have specialists for everything.

Here, you'll own problems end to end.

One week you might be designing backend services.

The next you'll improve frontend experiences.

The week after you'll be helping shape infrastructure or influencing product direction.

If you enjoy variety, ownership and solving difficult engineering problems, you'll feel at home.

You'll enjoy this role if you like:

• Building products from the ground up
• Working across the full stack
• Making architectural decisions
• Seeing the direct impact of your work
• Collaborating with AI Engineers
• Solving real engineering problems rather than maintaining legacy systems
• TypeScript
• Node.js
• React
• AWS
• Docker
• REST APIs
• CI/CD

We're far more interested in great engineers than someone who has used every tool on this list.

We\'d love to hear from you if you have experience with:

• Building or supporting software platforms that power AI or Machine Learning products in production
• Commercial software engineering (5+ years)
• TypeScript and Node.js
• Cloud-native applications
• Building production software
• Designing scalable APIs
• Modern software architecture

What you'll get

• Hybrid working with flexibility
• A genuinely small engineering team where your voice matters
• The opportunity to shape architecture, engineering practices and product direction
• The chance to build software powering real-world AI

If you're looking for more ownership, greater technical influence and the opportunity to help build something from an early stage, we'd love to hear from you.