Mid-Level Python Developer at Mossend Software, London EC4M, £350 per day (Outside IR35)

Python Developer (Azure / FastAPI) — £350/day — Outside IR35 — Hybrid, Central London (3 days on-site)

About the role

A significant opportunity to work with a leading global independent financial services firm, delivering a loan management platform that handles complex servicing workflows in a regulated environment. You'll be working to a high bar for correctness, traceability and testing — and you'll be based out of excellent offices in central London three days a week.

We are looking for a mid-level Python developer to join the delivery team. This is a hands-on engineering role in a small, senior team — you'll own features end to end and you'll have direct visibility of the client and the business problems you're solving.

What you'll be doing

• Building and maintaining Python services — FastAPI applications and Azure Functions
• Designing and consuming REST APIs, with an eye on validation, versioning and clear contracts
• Working with MS SQL Server: query tuning, stored procedures and migrations
• Working with Azure infrastructure — storage, queues, app configuration, monitoring
• Writing and maintaining automated tests
• Debugging and resolving defects in a live platform, including root cause analysis

Essential

• Solid commercial Python (typically 3+ years)
• Production experience with FastAPI, or a close equivalent such as Flask or Django REST
• Practical experience building serverless services on Azure Functions
• Strong MS SQL Server — you can write and optimise non-trivial queries, not just ORM calls
• Working knowledge of Azure cloud services and infrastructure
• Git, CI/CD pipelines, and a genuine testing habit
• Comfortable working directly with client stakeholders

Nice to have

• Financial services, lending or another regulated domain
• SQLAlchemy or Alembic
• Infrastructure as code (Bicep or Terraform)
• Azure DevOps
• Experience in a consultancy or client-facing delivery setting

Details

• Rate: £350 per day
• IR35 status: Outside IR35
• Contract length: 6 months minimum, with strong potential to extend
• Location: Hybrid — 3 days per week on-site, central London
• Start: [ASAP / September 2026]

To apply

Send your CV through Indeed with a short note on a recent Python and Azure project you worked on and what your part in it was. No agencies.

Pay: From £350.00 per day

Work Location: Hybrid remote in London EC4M