David Jahn Email & Phone Number

Deland, Fl, Us

Deland, Fl, Us

Lake Wales, Fl, Us

• Developed prototype reports on business profitability using Power BI platform.• Provided Power BI transformation, data modeling, and visualization expert assistance to analysts transitioning to Power BI for niche business uses.• Assessed effort needed to convert complex Excel spreadsheet to SQL/Power BI system.

San Jose, Ca, Us

Developed Azure Synapse Spark notebooks using Python and PySpark to enrich and refine application data, optimizing it for reporting needs and machine learning processes.Optimized data workflows by configuring Azure Synapse Pipelines to transform and refine data from SQL databases into Azure Data Lake and Cosmos to enable reporting and provide richer data in the end-user web application.Created Power BI reports on Azure Data Lake datasets to showcase key data trends and highlight data anomalies.Developed Synapse Spark notebooks to revitalize legacy Power BI reports by pre-summarizing detailed data to the levels needed by the visualizations, then rebuilt the reports to use the summarized datasets. This greatly improved reporting performance and reduced the Power BI dataset sizes.

San Ramon, Ca, Us

I improved retail sales analytics and payment system monitoring by leading a technical team in building a new big data cloud system with real-time transaction visibility. Along with guiding the technical team, I worked on many Azure data and ingestion services myself. In the same manner, I developed and guided developers on the Power BI reports and dashboards that use this data to monitor and analyze real-time and historical transactions. My Azure service experience includes IoT Hub, Event Hub, Stream Analytics, Azure SQL, Data Explorer (as our primary, hot/cold, big data repository), BLOB storage, and Azure Data Factory (now part of Azure Synapse).

San Ramon, Ca, Us

I Improved retail sales volume and customer experience by leading a small team of C# .NET developers to maintain the IT systems for the corporation's real-time customer loyalty program with Albertsons/Safeway. My team was consistently recognized for continually achieving exceptionally high reliability and data integrity while accommodating program changes and integrating different Point of Sale devices over time.

San Ramon, Ca, Us

As a senior software engineer, I designed, built, led other developers, and/or supported many critical corporate .NET applications during this role. These highly impactful systems include ones that were used by all employees to manage their careers, by all managers to determine employee annual pay and performance, by the CEO and board to manage the secure distribution of sensitive corporate documents.

San Ramon, Ca, Us

As a software engineer, I successfully developed applications on a broad variety of platforms and technologies, including mainframe, SAP, ASP web. In the late 1990s, I was among the company's pioneers for developing personal computer applications, using Power Builder to create a front-end for mainframe screens. This improved the usability and productivity for our HR representatives in maintaining employee data.I retrofitted a set of mainframe processing to accommodate full-sized year fields, successfully preventing any Y2K malfunctions. I also played an important role in converting the company's HR systems from mainframe to SAP, redesigning and building a number of the interfaces to other applications and external partners.