Tim Allan
Senior Data Engineer & BI Architect
Bromley, London · LinkedIn · GitHub
Profile
Data engineering leader with over 20 years of experience architecting enterprise-scale data warehouses, building ETL pipelines, and delivering business intelligence solutions that drive strategic decision-making. I specialise in transforming complex, disparate data sources into unified, high-performance analytics platforms that serve thousands of users.
Throughout my career, I have built and led high-performing data teams, implemented modern DevOps practices for data infrastructure, and delivered solutions processing millions of transactions across global operations. I combine deep technical expertise in SQL Server, Python, and Power BI with strong business acumen in financial and operational analytics.
Technical Expertise
Data Engineering & Warehousing
SQL Server · T-SQL · SSIS · Kimball Methodology · Star & Snowflake Schema Design · ETL Pipeline Development · Data Modelling · Informatica
Analytics & Visualisation
Power BI · DAX · SSAS · Cognos · Advanced Excel · Real-time Dashboards · Self-Service BI
Development & Automation
Python (Pandas, NumPy, Scikit-learn) · Git & GitHub · Azure DevOps · CI/CD Pipelines · VBA · PL/SQL
Platforms & Tools
Microsoft Azure · Salesforce & SOQL · PeopleSoft · SQL Server Management Studio · Azure Data Studio · VS Code · Jupyter Notebooks
Career History
Sprint Enterprise Technology
Senior Data Engineer · November 2022 – Present
Adecco UK & Ireland
Business Intelligence & System Accounting Manager · August 2014 – October 2022
Led a team of 9 data professionals delivering enterprise BI and data warehousing solutions for one of the world’s largest recruitment companies. Reported directly to the Group Finance Director with responsibility for all data infrastructure across UK & Ireland operations.
Key Achievements:
- Architected a Salesforce data warehouse integrating CRM data with multiple business systems, enabling analysis of 40+ KPIs to identify high-value sales pipelines and optimise team performance
- Delivered near real-time Power BI analytics to 1,900 users with hourly data refreshes, drill-down functionality, and direct Salesforce record linking
- Engineered a global ETL pipeline feeding CRM data into Informatica-based global data warehouse, supporting operations across 60 countries
- Implemented DevOps practices using Git and GitHub, enabling collaborative development and reducing deployment downtime
- Built the business case for Power BI Premium, successfully securing executive investment to modernise the company’s analytics capabilities
- Designed payroll and billing data warehouse enabling detailed client analysis to identify and re-engage lapsed accounts
Business Intelligence Manager · July 2010 – August 2014
Managed the BI function through a major organisational restructuring, rebuilding the team from the ground up while maintaining service delivery.
- Rebuilt the entire BI team after restructuring—recruited, trained, and developed 6 analysts while reducing headcount through strategic automation
- Delivered HMRC legislative reporting on schedule with zero budget through innovative resource allocation
- Consolidated 9 disparate data sources into a unified ETL framework using SQL Server and Cognos
Systems Accountant · November 2006 – July 2010
- Served as Subject Matter Expert for PeopleSoft 9.0 implementation, leading data migration and reconciliation of 44 million transactions
- Developed automated margin accrual system for multiple brands with combined annual turnover exceeding £400 million
- Built P&L reporting solution using Cognos and SQL Server, transforming financial reporting capabilities
Earlier Roles · January 2003 – November 2006
Progressive career growth through Assistant Management Accountant, Commissions Analyst, Senior Payments Co-ordinator, and Electronic Data Manager positions—building foundational expertise in payroll systems, financial processes, and data management.
Education
BSc (Hons) Natural Sciences: Physics and Astronomy
The Open University · First Class Honours · 2011–2015
Advanced coursework in quantum mechanics, astrophysics, and general relativity. Final year project: computational analysis of co-orbiting exoplanet detection methods.
Certifications
Microsoft Certified: Azure Fundamentals (AZ-900) · 2022
Stanford University Machine Learning · Coursera · 2021
Introduction to Programming in C++ · edX · 2021
Microsoft Office 2013 Master Specialist · 2015
edX Data Science & Analytics Track: Power BI · Python for Data Science · Data Analysis with Python · Transact-SQL · Excel for Data Analysis · 2015–2019
Leadership & Soft Skills
Team Leadership & Development · Stakeholder Management · Executive Communication · Requirements Analysis · Agile Project Delivery · Technical Documentation · Training & Mentoring · Vendor Management