Backend Engineer

Harnham - Data & Analytics Recruitment; City Of London; On-site; GBP 72,000 - 88,000; Full time

Benefits offered by this job

Contributory pension scheme

Bonus

Job summary

Harnham - Data & Analytics Recruitment is seeking a Backend Engineer in London to build scalable services and AI-powered capabilities. You will work across the full stack, integrating Java/Spring with Python-based AI services, and design secure, high-performance systems in a fast-paced environment.

The role emphasizes API design, observability, automated testing, and cloud infrastructure, with opportunities to contribute to production-ready, data-driven solutions in an early-stage tech setting.

Qualifications

• Experience building backend applications.
• Proficient Python with FastAPI desirable.
• Strong SQL and PostgreSQL expertise.
• Hands-on AWS experience with CI/CD and Linux environments.
• Knowledge of API design, testing, monitoring, observability and security.

Responsibilities

• Build, scale, and maintain backend services including APIs, workflow engines, data services, and system integrations.
• Develop integrations between Java/Spring components and Python-based AI services.
• Design secure, reliable, high-performance systems.
• Collaborate with cross-functional teams to deliver robust backend solutions.
• Implement and enhance API architectures, observability frameworks, automated testing, and security practices.
• Contribute to cloud infrastructure, CI/CD pipelines, and AWS-based operations.

Skills

Backend development

Python

FastAPI

SQL

PostgreSQL

AWS

API design

Security

Observability

AI tools

Java/Spring

LLM integrations

Tools

Cursor

Claude Code

Job description

BACKEND ENGINEER
UP TO £80,000
LONDON

This is an exciting opportunity to join an early-stage technology business where AI sits at the heart of product development and innovation. You'll play a key role in shaping a product from the ground up, working across the full technology stack and helping to deliver AI-powered capabilities that solve complex real-world problems.

THE COMPANY

Our client is a technology-driven organisation focused on developing software solutions that help businesses manage complex workflows, data, and decision-making processes. They operate in a collaborative, fast-paced environment where engineering, product, and business teams work closely together to deliver high-impact solutions. They offer the opportunity to work on technically challenging projects while contributing to the evolution of a rapidly growing product.

THE ROLE

Responsibilities include but are not limited to:

• Build, scale, and maintain backend services, including APIs, workflow engines, data services, and system integrations.
• Develop and support integrations between Java/Spring platform components and Python-based AI services.
• Design secure, reliable, and high-performance systems.
• Collaborate with cross-functional engineering teams to deliver robust backend solutions for demanding production environments.
• Implement and enhance API architectures, observability frameworks, automated testing, and security best practices.
• Contribute to cloud infrastructure, CI/CD pipelines, and operational excellence across AWS-based environments.

YOUR SKILLS AND EXPERIENCE

• Strong commercial experience building backend applications.
• Strong Python experience is essential, with FastAPI as highly desirable
• Strong SQL and PostgreSQL expertise.
• Hands-on AWS experience, including cloud-native services, CI/CD pipelines, and Linux-based environments.
• Strong knowledge of API design, testing strategies, monitoring, observability, and application security.
• Regular use of AI-assisted development tools such as Cursor, Claude Code, or similar productivity tools.
• Experience with Java/Spring, event-driven architectures, workflow engines and LLM integrations is highly desirable.

SALARY AND BENEFITS

• Up to £80,000 base salary
• Contributory pension scheme
• Bonus