Principal Software Engineer/ Tech Lead (Python/ Azure) - Financial Services

Sterlings; Greater London; Hybrid; GBP 120,000 - 150,000; Full time

Job summary

Sterlings is seeking a Principal-level engineer to lead hands-on Python development for cloud-based APIs and integrations in a cloud-first environment.

You will shape architecture, collaborate with architects, product owners and delivery teams, and mentor engineers to raise technical capability. The role balances technical leadership with ongoing hands-on work and is based in London with 2–3 days in the office.

Qualifications

• Solid experience designing REST APIs and microservices.
• Proven ability to work with event-driven architectures.
• Strong cloud-native and serverless development skills.
• Experience guiding architecture and technical direction.
• Comfortable communicating complex concepts to varied audiences.
• Experience in Agile/Scrum/Kanban environments.

Responsibilities

• Designs and develops scalable Python-based cloud apps, APIs and microservices.
• Leads architectural decisions and engineering standards across teams.
• Guides integration architectures in complex enterprise environments.
• Mentors engineers and raises technical capability across the team.
• Drives CI/CD, modernisation and automation initiatives.
• Collaborates with architects, product owners and senior stakeholders.

Skills

REST APIs

Microservices

Event-driven

Cloud-native

Serverless

Architectural direction

Agile/Scrum/Kanban

Communication

Azure DevOps

Tools

Azure Functions

Terraform

GitLab CI

IBM ACE/API Connect

Job description

What you’ll be doing:

• Designing and developing scalable Python-based cloud applications, APIs and microservices
• Working across Azure Functions, serverless, containers, APIM and cloud services
• Designing event-driven and integration architectures across complex enterprise environments
• Providing technical direction on architecture, design decisions, standards and engineering practices
• Working closely with architects, product owners, delivery teams and senior stakeholders
• Mentoring engineers and helping raise technical capability across the wider team
• Driving modernisation, automation, CI/CD and continuous improvement

What we’re looking for:

• Strong understanding of REST APIs, microservices and event-driven architecture
• Experience with secure integration
• Good understanding of cloud-native and serverless development
• Experience influencing architecture and technical direction
• Comfortable communicating complex technical concepts to both technical and non-technical audiences
• Experience working within Agile/Scrum/Kanban environments
• Experience with Azure DevOps/GitLab CI, Terraform, IBM ACE or API Connect would be advantageous.

Sterlings are currently working with a leading UK Financial Services organisation that is investing heavily in modernising its technology estate, and we’re looking for a Principal-level engineer/ technical leader to play a key role in that journey.

This is a genuinely hands‑on technical position, combining Python development, Azure, API integration, cloud‑native architecture and technical leadership. You’ll be working on complex, high-profile initiatives and helping shape how modern integration solutions are designed and delivered.

This would suit someone who is still technically hands‑on, but is looking for the opportunity to operate at a Principal/Technical Lead level and have genuine influence over engineering and architecture decisions.

This role is 2/3 days in the London office.