Senior Backend Engineer - Python, FastAPI

We are looking for a highly specialized Senior Backend Engineer to join our team as a technical cornerstone for one of our key UK-based partners. In this role, you will be responsible for the architecture, development, and maintenance of server-side logic designed to empower and scale small businesses globally.

As a Senior specialist, you will view backend development as a craft. You’ll be tasked with building high-performance APIs and event-driven microservices, ensuring that every line of code prioritizes security, scalability, and an exceptional developer experience. We need a professional who is as comfortable optimizing a complex Postgres query as they are architecting an entire asynchronous ecosystem using AWS SQS, SNS, and Lambda .

Must Have

• 7+ years of professional experience in backend development, with at least 5 years dedicated to the Python ecosystem as your primary language.
• Python Framework Mastery: Expert-level proficiency in Django, FastAPI, and Flask , understanding when to use each based on project needs (monolithic vs. high-performance microservices).
• Solid Engineering Fundamentals: Deep understanding of SOLID principles , design patterns, and ACID properties in database transactions.
• AWS Cloud-Native Expert: Proven track record deploying and managing services including AWS Lambda, Fargate, EKS, and S3 .
• API Architect: Extensive experience building, documenting, and integrating complex REST APIs with a focus on performance and security.
• Database & Data Orchestration: Expert knowledge of PostgreSQL (modeling and optimization) and experience working with big data environments like Google BigQuery .
• Messaging & Event-Driven Design: Practical experience using AWS SQS and SNS to decouple services and handle asynchronous workloads.
• Infrastructure as Code (IaC): Hands-on experience with Terraform to manage and version cloud resources.
• Hardcore Testing & Quality: Absolute commitment to automated testing (Pytest, Unittest) and following Scrum/Agile best practices.
• English B2-C1: Ability to lead technical design reviews and communicate effectively with stakeholders in the UK and globally.
• AI-Assisted Development: Proficiency in using AI tools (Cursor, Claude code) to accelerate delivery without sacrificing code integrity or security.

Nice to have

Salesforce Integration: Familiarity with integrating Python backends with Salesforce environments.

Observability: Experience implementing monitoring and error tracking using Sentry.

DevOps Mindset: Experience building CI/CD pipelines (GitHub Actions, AWS CodePipeline) and managing containerized applications.

Security First: Familiarity with OWASP standards and AWS IAM best practices.

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