Senior AI Software Engineer - Production LLM & Cloud Apps

Harrington Starr; United Kingdom; On-site; GBP 90,000 - 130,000; Full time

Job summary

Harrington Starr is seeking a Senior AI Software Engineer to own the design and delivery of production-grade AI solutions. You will work across backend services, frontend applications and cloud infrastructure, turning LLM capabilities into reliable business products for financial services.

Lead the implementation of AI integrations, drive architecture decisions, and collaborate with product and engineering to scale the platform.

Qualifications

• Experience delivering production AI-powered applications.
• Hands-on with LLM-powered products and agentic workflows.
• Strong fundamentals in software engineering and cloud-native design.

Responsibilities

• Build and deploy production AI applications using LLMs, RAG and agentic workflows.
• Develop scalable backend services and APIs using Node.js and TypeScript.
• Build modern frontends with React and ensure robust UX.
• Design cloud-native architectures across AWS and related services.
• Improve AI reliability via monitoring, observability and testing.
• Own features end-to-end from design to deployment and optimization.
• Mentor engineers and influence technical direction.

Skills

LLMs & AI integrations

Node.js

TypeScript

React

AWS

RAG & agentic workflows

API design & microservices

Tools

Node.js tooling

TypeScript tooling

React tooling

AWS services

REST APIs

Job description

Harrington Starr is seeking a Senior AI Software Engineer to own the design and delivery of production-grade AI solutions. You will work across backend services, frontend applications and cloud infrastructure, turning LLM capabilities into reliable business products for financial services.

Lead the implementation of AI integrations, drive architecture decisions, and collaborate with product and engineering to scale the platform.