Senior Backend Engineer

Role: Backend Engineer

Location: UK

Contract Length: 12 Months

LSI are working with a global technology consultancy that partners with some of the world's leading organisations to deliver cutting-edge digital products and AI-driven solutions. Due to continued growth, they're looking to hire an experienced Senior Backend Engineer to join a high-performing engineering team working on complex, enterprise-scale applications.

This is an opportunity to play a key role in designing and building scalable backend systems while working alongside talented engineers across multiple international locations. You'll be involved in developing modern cloud-native applications, contributing to architectural decisions, and helping shape the next generation of AI-enabled software.

The Role

As a Senior Backend Engineer, you'll be responsible for developing robust, high-performance backend services that power large-scale digital platforms. You'll work within an agile environment, collaborating closely with product owners, architects and engineers to deliver secure, scalable and maintainable solutions.

Key Responsibilities

• Design, develop and maintain scalable backend services using Python.
• Build and optimise RESTful APIs using FastAPI or Flask.
• Develop cloud-native microservices deployed with Docker and Kubernetes.
• Deliver event-driven solutions using messaging technologies and distributed architectures.
• Work extensively with AWS services including Lambda, SQS, Step Functions, DynamoDB and RDS.
• Optimise search functionality using Elasticsearch or OpenSearch.
• Collaborate with global engineering teams on architecture, delivery and continuous improvement.
• Contribute to CI/CD pipelines and engineering best practices.
• Ensure solutions are secure, resilient and highly performant.
• Support the development of AI-enabled applications, including GenAI and Retrieval-Augmented Generation (RAG) initiatives where applicable.

Required Experience

• Strong commercial experience developing backend applications in Python.
• Experience with FastAPI and/or Flask.
• Proven background building microservices architectures.
• Hands-on experience with Docker and Kubernetes.
• Strong AWS experience across serverless and cloud-native services.
• Experience with Elasticsearch, OpenSearch or similar enterprise search technologies.
• Knowledge of event-driven architectures and messaging systems.
• Experience working with relational and NoSQL databases such as MySQL, MongoDB, DynamoDB or Snowflake.
• Familiarity with CI/CD pipelines and DevOps practices.
• Strong understanding of backend security, scalability and performance optimisation.