Power BI Consultant

Power BI Data & Risk Reporting Consultant, £450-500 per day (inside) | 6-Month Contract | Immediate Start | 3 Days per Week Onsite Role Overview Our client, the securities division of a global bank, is looking for a senior Power BI specialist to support the expansion of enterprise risk reporting. This is not primarily a dashboard development role. The key challenge is building and optimising Power BI semantic models that can efficiently handle large volumes of data and complex financial calculations. The successful candidate will work closely with an existing data engineering team and be responsible for improving report performance, model scalability, refresh times, and calculation efficiency across a global reporting environment. Key Responsibilities • Design and optimise Power BI semantic models for large-scale datasets. • Develop and optimise complex DAX calculations and financial metrics. • Improve report refresh performance and data processing times. • Reduce performance issues caused by model design and calculation logic. • Support the scaling of risk reporting into additional business functions. • Work with globally distributed teams across London, New York, Tokyo and Hong Kong. • Help design robust processing and reporting approaches that support global operating models. Essential Skills & Experience • Advanced Power BI development and semantic modelling experience. • Strong DAX expertise, including performance optimisation. • Proven experience handling large data volumes within Power BI. • Experience troubleshooting: • Slow refreshes • Performance bottlenecks • Large semantic models • High-complexity calculations • Strong understanding of data modelling principles and optimisation techniques. • Financial services or investment banking experience. • Experience working with front-office reporting environments. Nice to Have • Market Risk reporting experience. • Knowledge of Value at Risk (VaR) and Stress Testing calculations. • Credit Risk reporting exposure. • Experience supporting global reporting or batch-processing environments. Suggested Interview Questions 1. Power BI & Data Modelling Tell us about the largest Power BI model you've worked on. What performance challenges did you face and how did you resolve them? Looking for: • Large datasets • Semantic model optimisation • Refresh improvements • Data modelling best practice 1. DAX & Financial Calculations Describe a complex DAX calculation you've built and how you optimised it for performance. Looking for: • Strong DAX knowledge • Use of VAR and optimisation techniques • Understanding of filter and row context • Performance tuning experience 1. Large Volume Data Processing How would you approach a Power BI model that is struggling with refresh times due to increasing data volumes? Looking for: • Incremental refresh • Aggregations • Model redesign • Moving logic out of the semantic model where appropriate 1. Global Processing Challenges How would you manage reporting processes where multiple global regions are updating data at the same time? Looking for: • Understanding of batch processing • Data consistency and governance • Stakeholder coordination • Ability to balance business and technical requirements 1. Financial Services Experience Tell us about your experience supporting reporting within a capital markets, securities, trading or risk environment. Looking for: • Front-office exposure • Financial products knowledge • Understanding of financial calculations and reporting requirements 1. Risk Reporting (Nice to Have) Have you worked with Market Risk, VaR, Stress Testing or Credit Risk reporting? If so, what was your involvement? Looking for: • Practical experience rather than theoretical knowledge • Awareness of reporting complexity and performance implications What Good Looks Like The ideal candidate is: • A Power BI performance and modelling specialist. • Strong in DAX and financial calculations. • Experienced handling large and complex datasets. • Comfortable operating in a front-office banking environment. • Able to balance reporting requirements with performance and scalability considerations. Important: A candidate who is primarily a dashboard developer without strong experience in semantic models, DAX optimisation and large-scale data performance would not be suitable for this engagement.