Requirements
- 7+ years of professional experience in backend development, with at least 5 years dedicated to the Python ecosystem as primary language
- Expert-level proficiency in Django, FastAPI, and Flask, understanding when to use each based on project needs (monolithic vs. high-performance microservices)
- Deep understanding of SOLID principles, design patterns, and ACID properties in database transactions — and the ability to justify their application with concrete reasoning
- Proven, practical experience designing and operating microservices at scale
- Implementing idempotency keys, safe retries, and explaining what breaks without them
- Experience with saga and outbox patterns for distributed transactions
- Experience with circuit breakers, retry/backoff strategies, and eventual consistency trade-offs in a financial context
- Catches security vulnerabilities unprompted during code review: authentication and authorization gaps, IDOR, injection vectors, and broken access control
- Deep understanding of auth schemes, token validation, and why shortcut patterns are exploitable
- Applies OWASP Top 10 as a default lens, not an afterthought
- Systematic approach to input validation including edge cases (zero values, boundary conditions, negative inputs) — especially in payment and pricing flows
- Structures exception handling intentionally: avoids swallowing generic exceptions, returns correct HTTP status codes, and prevents cascading 500 errors
- Validates outputs from external service calls (payment gateways, inventory services, notification services) before acting on them
- Extensive experience building, documenting, and versioning complex REST APIs with a focus on performance, security, and developer experience
- Expert knowledge of PostgreSQL including data modeling, query optimization, and indexing
- Deep understanding of transaction management: knows exactly what a transaction fixes, when to use locking strategies, and how to prevent race conditions in concurrent financial operations
- Practical experience with message brokers (Kafka, RabbitMQ, AWS SQS/SNS, or equivalent) to decouple services and handle asynchronous workloads reliably and safely
- Absolute commitment to automated testing (Pytest, Unittest) including edge case and failure path coverage, not just happy-path scenarios
- Follows Scrum/Agile best practices
- Ability to lead technical design reviews and communicate effectively with stakeholders in the UK and globally
- Can articulate the reasoning behind every technical decision with depth and precision (English B2–C1)
- Familiarity with payment processing concepts, financial transaction integrity, and the regulatory sensitivity of financial data
Nice to Have
- Familiarity with integrating Python backends with Salesforce environments
- Experience implementing monitoring and error tracking using Sentry
- Experience building CI/CD pipelines (GitHub Actions, AWS CodePipeline) and managing containerized applications
- Familiarity with OWASP standards and AWS IAM best practices
Work Arrangement
Remote (Worldwide) — UK, India
Additional Information
- English B2–C1 proficiency required
- Role involves working with stakeholders in the UK and globally
