Senior Software Engineer - Python

Spencer Rose Ltd; Watford; Hybrid; GBP 70,000 - 75,000; Full time

Job summary

Spencer Rose Ltd in Watford, Hertfordshire is seeking a Senior Software Engineer - Python to build high-throughput, API-first back-end services. You will design, implement and maintain production-grade Python applications, focusing on reliability, performance and scalable architecture.

The role is hybrid with 2-3 days in the Watford office. You will collaborate with Principal Engineers, mentor peers, review code, and help shape the roadmap while delivering with modern practices such as CI/CD,

Qualifications

• Experienced Python Developer with design-for-scale approach.
• Senior-level experience building production Back End services in Python (3.10+).
• Strong background in high-throughput, message-based or event-driven systems.
• Proven experience building API-first services focused on performance and reliability.
• Python Back End development using FastAPI and modern API patterns.
• Solid understanding of RESTful API design, schema validation, and OpenAPI/Swagger.
• Experience with messaging/eventing platforms such as Kafka, RabbitMQ, Azure Service Bus, MQTT, or similar.
• Cloud-native development experience (ideally Azure).
• Hands-on with Docker and Kubernetes.

Responsibilities

• Collaborate closely with Principal Engineers and provide technical guidance.
• Mentor other engineers and participate in peer reviews.
• Support stakeholders in shaping the roadmap and standards.
• Translate requirements into technical specifications and tasks.
• Maintain accurate technical documentation and deliver unit-tested code.
• Lead troubleshooting, incident resolution, and occasional out-of-hours support.
• Ensure solutions meet acceptance criteria, performance and reliability goals.
• Integrate products with monitoring and support tooling.

Skills

Python

API-first design

Back-end design

RESTful APIs

OpenAPI/Swagger

Distributed systems

Cloud/Azure

Docker

Kubernetes

Kafka

RabbitMQ

Event-driven

Tools

Docker

Kubernetes

Kafka

RabbitMQ

Azure Service Bus

OpenAPI/Swagger

Job description

Senior Software Engineer - Python

Watford, Hertfordshire (Hybrid)

£70,000 - £75,000 per annum + Excellent benefits

On behalf of an industry Leading organisation, I am seeking a Senior Software Engineer - Python with strong production experience building high-throughput, message-driven platforms. This role suits someone comfortable working on real-world, always-on systems where reliability, performance, and clear engineering judgement matter as much as clean code.

The business is pleased to offer this role on a hybrid basis with 2-3 days in office; therefore, you must be within easy reach of their Watford-based offices.

Responsibilities:

• Collaborate closely with Principal Engineers.
• Provide technical guidance, insight, and mentorship to other engineers.
• Participate in peer reviews and offer constructive feedback.
• Support product stakeholders in shaping the roadmap.
• Contribute to best practices and engineering standards across the wider engineering organization.
• Participate in modern software development practices including pairing, code reviews, documentation reviews, testing, and continuous delivery.
• Translate requirements into implementable technical specifications and tasks.
• Maintain accurate and reliable technical documentation.
• Provide regular updates on progress, timelines, risks, and dependencies.
• Lead troubleshooting and incident resolution, including occasional out-of-hours support.
• Ensure unit tests are implemented and fit for purpose.
• Research and evaluate new technologies that could benefit the organisation.
• Design and develop high-quality Python software that meets complex business needs.
• Ensure code, documentation, and testing align with engineering standards.
• Deliver solutions that meet acceptance criteria, performance expectations, and operational reliability.
• Integrate products with monitoring and support tooling.

Experience/Skills required:

• Experienced Python Developer who can make sound trade-offs, design for scale, and contribute to complex systems without over-engineering.
• Strong engineering judgement and real-world delivery experience.
• Senior-level experience designing and building production Back End services in Python (3.10+).
• Strong background in high-throughput, message-based or event-driven systems.
• Proven experience building API-first services, with a focus on performance, reliability, and maintainability.
• Python Back End development, primarily using FastAPI and modern API patterns.
• Strong understanding of RESTful API design, schema validation, and OpenAPI/Swagger.
• Experience working with messaging and eventing platforms such as Kafka, RabbitMQ, Azure Service Bus, MQTT, or similar.
• Cloud-native development experience is essential (ideally on Azure).
• Hands-on experience with containerisation (Docker) and orchestration platforms such as Kubernetes.
• Exposure to building and supporting shared or internal libraries used across multiple services.