Senior Software Engineer Python

Harnham - Data & Analytics Recruitment; City Of London; Hybrid; GBP 60,000 - 80,000; Full time

Job summary

A multi-award-winning digital agency in London seeks a Senior Software Engineer proficient in Python to develop and maintain scalable applications. The role involves working on data-driven tools and collaborating closely with engineering teams. Ideal candidates have over 5 years of experience, particularly with cloud-native development and modern engineering practices. The position offers hybrid flexibility with 1-3 days in the office and competitive benefits.

Benefits

Competitive salary

Hybrid working model

Development programs

Qualifications

• 5+ years of experience as a Software Engineer, ideally in Python (3.10+).
• Proven experience developing cloud-native applications (GCP or AWS).
• Strong understanding of CI/CD pipelines and containerization.

Responsibilities

• Designing, building, and maintaining scalable Python-based applications.
• Developing internal tools and automation.
• Building, testing, and deploying RESTful APIs.

Skills

Python programming

Cloud-native application development

CI/CD pipelines

Containerisation (Docker)

RESTful APIs

Excellent communication

Tools

FastAPI

Django REST Framework

GitHub Actions

Job description

Senior Software Engineer (Python)

Hybrid London (1-3 days per week)

Up to £80,000 + Benefits

Are you a passionate Python engineer who thrives on building scalable, high-quality software? We're working with a multi-award-winning digital agency, recognised as one of the Sunday Times Best Places to Work, that's looking for a Senior Software Engineer (Python) to help shape the next generation of their data-driven tools and products.

Why this role?

• Work at the intersection of data, automation, and AI, delivering tools that drive measurable impact for global brands.
• Join a collaborative, innovative engineering culture where learning, experimentation, and technical excellence are at the core.
• Hybrid flexibility: 1-3 days per week in the London office, balance the rest remotely.
• Be part of a company that has won multiple Performance Marketing Employer of the Year awards - and genuinely invests in its people.

What you'll be doing:

• Designing, building, and maintaining scalable Python-based applications and microservices.
• Developing internal tools and automation to support both client delivery and internal teams.
• Building, testing, and deploying RESTful APIs using frameworks like FastAPI or Django REST Framework.
• Collaborating with data and platform engineers to integrate new features and optimise performance.
• Ensuring robust engineering practices including CI/CD, TDD, and secure development.
• Supporting and mentoring junior engineers, helping raise the technical bar across the team.
• Staying hands-on while contributing to the architectural direction and long-term roadmap.

What we're looking for:

• 5+ years of experience as a Software Engineer, ideally in Python (3.10+).
• Proven experience developing cloud-native applications (GCP or AWS).
• Strong understanding of CI/CD pipelines (e.g. GitHub Actions) and containerisation (Docker).
• Experience designing scalable, secure systems using modern principles (SOLID, TDD).
• Familiarity with databases (SQL, NoSQL, or graph) and API integrations.
• Excellent communicator who thrives in a collaborative, fast-paced environment.

Nice-to-haves:

• Experience with Generative AI / LLMs in applied engineering contexts.
• Exposure to infrastructure-as-code (Terraform, CloudFormation, or CDK).
• Familiarity with Vue.js or other front-end frameworks for collaboration with UI teams.