Contract - Back End Developer - Python/AWS - 500-700/day (Outside IR35) - ID44270

Senior Backend Engineer Python | Django | FastAPI | AWS

Build systems that power the future of AI

Are you a high-agency backend engineer who thrives on solving complex problems at scale?

Do you enjoy designing secure, production-grade systems and shipping robust APIs that make advanced technology accessible?

Would you like to shape core infrastructure for AI-powered products in a fast-paced, ambitious environment?

If this sounds like your kind of challenge this could be the opportunity that unlocks your next big career move.

About the Role

Our client an innovative, deep tech start-up based in the UK is seeking a Senior Backend Engineer with expertise in Python (Django or Flask) to architect and deliver production-grade systems for cutting-edge AI products. This is a role for engineers who enjoy owning backend services end-to-end from design to deployment and everything in between.

You'll play a pivotal role in building secure, scalable APIs, optimising infrastructure, and integrating backend services directly with AI models and real-time inference pipelines.

This is a hybrid role with flexible hours , offering rapid career progression and a chance to define best practices from the ground up in a company that genuinely values engineering excellence.

Why This Role is Great

In this role, youll get to:

• Design scalable backend architecture using FastAPI and Python for high-performance workloads
• Build and maintain robust APIs following RESTful conventions and OpenAPI/Swagger standards
• Own the performance of PostgreSQL databases , including partitioning, indexing, and horizontal scaling strategies
• Secure and optimise infrastructure using Docker, AWS, and infrastructure-as-code (IaC) tools like Terraform
• Collaborate directly with AI and product teams , translating real-world requirements into elegant backend systems
• Mentor engineers and influence architecture , driving backend standards and operational excellence
• Take full ownership of systems in production , including logging, monitoring, incident response, and disaster recovery

About You

You might come from a variety of backgrounds, but youll thrive in this role if youre excited to:

• Work with modern tools like Python, FastAPI, PostgreSQL, Docker, and AWS
• Engage with real-time systems and AI model integration pipelines
• Build on your experience of deploying APIs, writing clear documentation, and maintaining strong testing practices
• Apply your knowledge of CI/CD tools like GitHub Actions or Argo CD to ship high-quality code fast
• Be hands-on with authentication systems (OAuth2, OIDC) and secure API design
• Operate with a security-first mindset , using tools like GuardDuty, CloudWatch, and IAM best practices
• Grow in a high-trust, high-ownership culture where autonomy is valued and impact is recognised

Ideal Skills Wishlist

(If you meet most of these, wed love to hear from you!)

• 5+ years of backend engineering, ideally in Python with Django, Flask, or FastAPI
• Proven experience building REST APIs in production
• Strong command of relational databases (especially PostgreSQL)
• Familiarity with containerisation (Docker) and version-controlled environments
• Hands-on AWS experience (VPC, EC2, S3, IAM, ALB/ELB, etc.)
• Exposure to CI/CD practices and infrastructure-as-code
• Comfortable leading backend projects and mentoring peers
• *Active MoD SC*

Diversity & Inclusion

Were committed to building teams that reflect a broad range of backgrounds, perspectives, and skills and so is our client. We actively encourage applications from all genders, ethnicities, abilities, and experiences. If you're passionate about backend engineering and think this role sounds exciting even if your CV doesnt tick every box we encourage you to apply.

Ready to Make a Real Impact?

If youre ready to join a team building AI systems that work at scale in the real world, wed love to hear from you.

Apply now to start a conversation about your next chapter as a Senior Backend Engineer.