Senior Software Engineer

Company Description

We're ASOS. We blend our flair for fashion with our love of cutting- edge technology, but more importantly were interested in how we can bring the best out of you.

We exist to give people the confidence to be whoever they want to be, and that goes for our people too. At ASOS, you're free to be your true self without judgment, and channel your creativity into a platform used by millions.

Job Description

We're looking for a Senior Software Engineer to join our FinOps team in London. ASOS runs a large Azure estate behind a platform used by millions of customers, and every architectural decision made across our engineering teams has a cost attached to it.

FinOps exists to make that cost visible, attributable and actionable, helping engineering teams understand what their services cost and make better technical decisions.

This is an engineering role, focused on building and running the platforms, data products and tooling that enable ASOS to understand and optimise cloud usage.

At this level, you'll take ownership of complex, high-impact problems, help shape technical direction and deliver reliable solutions into production. You'll work closely with Senior Engineers, Engineering Leads, Finance and Product Delivery Teams to build capabilities that are trusted and used across ASOS.

What You'll Be Doing

• Design and deliver the data products that make Azure cost visible and attributable across ASOS, including cost and usage pipelines, allocation and showback models, anomaly detection and reporting surfaces.
• Own the cost and usage data platform on Databricks, ingesting Azure Cost Management exports, reservation and Savings Plan data, resource inventory and tagging metadata into Delta Lake and modelling it into trusted datasets.
• Build and own Power BI semantic models behind cost reporting, including DAX measures, composite and DirectQuery designs, with model definitions managed as code through TMDL and XMLA.
• Lead optimisation work across the estate, including right-sizing, autoscaling, storage tiering, data transfer and egress patterns and orphaned resource cleanup.
• Own the platform the FinOps data products run on: Azure Functions, infrastructure as code in Bicep, managed identities and RBAC, multi-environment CI/CD in GitHub Actions, and the monitoring and alerting that keep it reliable in production, applying DevOps practices end to end.
• Engage directly with Product Delivery Teams, reviewing architectures, quantifying trade-offs and helping teams make efficient technical decisions.
• Build guardrails around cost allocation and cloud usage, including tagging policies, Azure Policy, budgets and exception reporting.
• Develop unit economics that connect cloud spend to business value, such as cost per order, customer or request.
• Support forecasting, budgeting and variance analysis with Finance and help explain movements in cloud spend.
• Set technical direction for FinOps engineering, contributing to architecture and design decisions and supporting other engineers through code reviews, design reviews and mentoring.
• Help shape how FinOps uses agentic AI, experimenting with tools such as GitHub Copilot and Claude Code to improve investigation, development and reporting workflows.
• Write high-quality, well-tested code and work with Cyber Security to ensure access, security and compliance requirements are embedded into the platform.

Beyond technical skills, we're looking for engineers who take ownership of what they build. You should be comfortable working across engineering teams, understanding the impact of your technical decisions and taking responsibility for systems throughout their lifecycle — from development through to production.

Additional Information

What's in it for you?

• Competitive salary, pension and private medical care scheme
• Performance-related bonus
• Flex benefits allowance — which you can choose to take as extra cash or use towards other benefits
• 25 days paid annual leave + an extra day for your birthday
• Employee discount (hello ASOS discount!)
• Tech Develops — our internal tech-focused skills development programme
• Opportunity to represent ASOS at industry-leading events
• Opportunity to help shape and drive our DE&I initiatives in Tech
• Opportunity to make an impact from day one and work with cutting-edge technolog

Qualifications

Essential

• Strong hands-on Azure engineering experience, including infrastructure as code and running services in production.
• DevOps skills and a you-build-it-you-run-it mindset, including CI/CD pipelines, ideally GitHub Actions, automated testing, safe promotion across environments, monitoring, alerting and incident response.
• Strong Python experience that you've owned in production, including building and maintaining production services or data products.
• Power BI semantic modelling and DAX experience, with an understanding of building and maintaining robust models rather than simply creating reports.

Nice to Have

• FinOps or cloud-cost experience, including Azure Cost Management exports, FOCUS, reservations or Savings Plans.
• Databricks and Delta Lake.
• KQL.
• Tmdl And Xmla.
• PowerShell.
• Experience with cloud cost optimisation, allocation/showback or cost attribution.

What We're Using

• Python — production services, data pipelines, automation and analysis
• Azure — Cost Management and Billing, Advisor, Azure Policy and Monitor
• Azure Functions and Bicep — serverless pipelines and infrastructure as code across multiple environments
• Entra ID — managed identities and RBAC across subscriptions
• Application Insights and Grafana — telemetry, monitoring and alerting
• Power BI — semantic modelling, DAX, composite and DirectQuery models, TMDL and XMLA
• Databricks — Delta Lake and SQL warehouses
• KQL — Azure Monitor, Log Analytics and resource telemetry
• GitHub and GitHub Actions — source control, CI/CD and automation
• Azure DevOps — work item tracking and pipeline management
• GitHub Copilot and Claude Code — agentic development and engineering workflows

Additional Information

What's in it for you?

• Competitive salary, pension, and private medical care scheme
• Performance related bonus
• Flex benefits allowance - which you can chose to take as extra cash, or use towards other benefits
• 25 days paid annual leave + an extra day for your birthday
• Employee discount (hello ASOS discount!)
• Tech Develops - our internal tech focussed skills development programme to focus on your personal growth as a technologist
• Opportunity to represent ASOS at industry leading events
• Opportunity to help shape and drive our DE&I initiatives in Tech (like our WIT movement and Diversity mentoring in Tech)
• Opportunity to make an impact from day one and work with the latest in cutting edge of technology