Senior Backend Engineer — AI-Driven End-to-End Features

Benifex Limited; Greater London; Hybrid; GBP 70,000 - 110,000; Full time

Benefits offered by this job

Tech setup

Learning budget

Flexible work

25 days holiday

Birthday off

Wellbeing days

Healthcare plan

Employee assistance

Income protection

Life insurance

Pension

Parental leave

Benifex card

Job summary

Benifex Limited, a fast-growing UK technology company, seeks a backend engineer to design and build features for Brain, our AI-powered product. You will leverage Python and .NET, work with LangChain/LangGraph, and collaborate with remote teams to ship robust APIs and services.

You will apply AI-native development practices, own delivery quality, and contribute to AI security, observability, and performance improvements across the stack. Flexible UK-based hybrid work is offered.

Qualifications

• Commercial GenAI experience (6+ months) including MCP and agent orchestration.
• Ability to deliver features end-to-end with initiative and minimal direction.
• Strong backend development experience with Python and SQL.
• Familiarity with AI coding assistants and AI native engineering practices.
• Experience with containerisation and CI/CD pipelines.

Responsibilities

• Design and build features for our flagship AI product Brain.
• Understand the Benefits product and APIs using Python/.NET experience.
• Own the quality of what you ship; test, fix defects, learn and improve.
• Write clear, maintainable code and provide feedback on PRs.
• Improve performance, security, and accessibility of systems.

Skills

Python

.NET

SQL

GenAI

CI/CD

AI security

Debugging

Production support

Tools

LangChain

LangGraph

Google ADK

Kubernetes

Google Pub/Sub

Job description

Benifex Limited, a fast-growing UK technology company, seeks a backend engineer to design and build features for Brain, our AI-powered product. You will leverage Python and .NET, work with LangChain/LangGraph, and collaborate with remote teams to ship robust APIs and services.

You will apply AI-native development practices, own delivery quality, and contribute to AI security, observability, and performance improvements across the stack. Flexible UK-based hybrid work is offered.