Backend Engineer

Harnham; Greater London; Hybrid; GBP 70,000 - 80,000; Full time

Benefits offered by this job

Bonus

Benefits

Hybrid London office

Job summary

Harnham in London is hiring a Backend Engineer to design, build and maintain scalable backend services. You will work with Python, SQL and cloud-native technologies to power AI-driven workflows and data platforms.

The role emphasizes security, observability and enterprise-grade reliability in a fast-growing AI software business. You will collaborate with cross-functional teams, influence architectural decisions and help shape engineering standards.

Qualifications

• Backend applications built with Python and SQL experience.
• Experience with PostgreSQL and API frameworks like FastAPI.
• Background in SaaS/enterprise-scale systems.
• Strong security, testing, observability and engineering practices.
• Experience operating applications in AWS.
• Familiar with CI/CD, Linux and modern engineering workflows.
• Experience with AI-assisted development tools.
• Experience with Java and Spring Boot.
• Knowledge of event-driven architectures and workflow orchestration.
• Experience with LLM integrations or AI-powered products.

Responsibilities

• Design, build and maintain scalable backend services using Python.
• Develop APIs, workflow services and data platforms for AI products.
• Build multi-tenant systems with focus on security and reliability.
• Integrate backend with AI/ML services.
• Improve observability via monitoring, logging and testing.
• Contribute to architecture decisions and engineering best practices.
• Support cloud infrastructure, deployment pipelines and production environments.
• Deliver highly available systems for enterprise customers.

Skills

Python

SQL

APIs

AWS

CI/CD

Linux

FastAPI

Java/Spring Boot

Event-driven

LLM integrations

Tools

PostgreSQL

FastAPI

AWS

Spring Boot

Job description

London (Hybrid, minimum 3 days in office) | £70,000 - £80,000 + Bonus + Benefits

This is an opportunity to join a well-funded AI software business building next-generation enterprise technology. You'll play a key role in developing the backend systems that power complex workflows, AI-driven capabilities, and large-scale data processing, while helping shape engineering standards in a growing team.

The Company

They are developing an AI-powered platform that enables organisations to manage complex workflows, data sources, and decision-making processes more efficiently. Operating within a high-growth environment, they combine advanced AI capabilities with enterprise-grade reliability, security, and compliance. Their engineering team is highly collaborative, with a strong focus on product quality, innovation, and ownership. They are investing heavily in technology and offer the chance to make a meaningful impact from day one.

The Role

You will:

• Design, build and maintain scalable backend services using Python and cloud-native technologies.
• Develop APIs, workflow services and data platforms that support AI-powered products.
• Build and optimise multi-tenant systems with a focus on security, reliability and auditability.
• Work closely with engineering teams to integrate backend systems with AI and machine learning services.
• Improve observability through monitoring, logging, testing and performance optimisation.
• Contribute to architecture decisions and engineering best practices.
• Support cloud infrastructure, deployment pipelines and production environments.
• Help deliver highly available systems used by enterprise customers.

Your Skills & Experience

You will have:

• Strong commercial experience building backend applications with Python and SQL.
• Experience working with PostgreSQL and API development frameworks such as FastAPI.
• A background developing SaaS, platform, or enterprise-scale systems.
• Strong understanding of security, testing, observability and software engineering best practices.
• Experience operating applications within AWS environments.
• Familiarity with CI/CD pipelines, Linux and modern engineering workflows.
• Regular use of AI-assisted development tools such as Cursor, Claude Code or similar.
• Java and Spring Boot.
• Event-driven architectures and workflow orchestration.
• LLM integrations or AI-powered products.
• Experience within regulated or data-intensive industries.

What They Offer

• Competitive salary, bonus and benefits package.
• The opportunity to build cutting-edge AI products with real-world impact.
• High levels of ownership and influence over technical decisions.
• Exposure to senior stakeholders and a collaborative engineering culture.
• Strong progression opportunities as the team continues to grow.
• Modern London office with a flexible hybrid working model.