Dorinna Pentchev

While studying Economics at the University of Exeter, Dorinna was first introduced to data analysis through learning about econometrics, machine learning and business analytics. She realised she enjoyed creating data visualisations and was particularly drawn to the wide scope of questions you can address with data, from business performance to text analysis of your favourite book.

During her first placement at HG Capital, Dorinna built several Tableau dashboards from scratch, developing her consulting skills to propose solutions with meaningful analysis to stakeholders.

In her following placement at IAG Cargo, she utilised Oracle SQL, Snowflake and Tableau on a daily basis to build data sources needed for operations reporting, identifying data issues, updating existing tables or dashboards, and building new reports to aid various parts of the business.

Dorinna has experience with different working environments, having spent her time at HG mainly focusing on one long project at a time, while her time at IAGC was spent working in an agile environment.

Certifications

Blog Posts

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Fri 02 Aug 2024 | Dorinna Pentchev
Improving performance of DAX calculations in Power BI
Say you’ve been handed a Power BI workbook which uses a large dataset and runs rather slowly. If your stakeholders don’t want to lose any functionality with the visualisations, you could look to improve performance by optimising the DAX calculations
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Fri 29 Jul 2022 | Dorinna Pentchev
Dashboard Week Day 5: Insert Sappy Title
For our final project of dashboard week, we were tasked with creating a dashboard using HR attrition data for a mock company.
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Thu 28 Jul 2022 | Dorinna Pentchev
Cheesus Christ it's Cheese.com
Today's challenge was mostly about data prep. Cheese.com sounds like a website that got its domain in 1999 and hasn't been updated since 2006, but lo and behold, the website we were tasked with scraping is a very current and detailed guide to all things cheesy
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Wed 27 Jul 2022 | Dorinna Pentchev
Dashboard week day 2: Is your country good at football?
Attempting a more infographic-styled visualisation of FIFA World Cup data.
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Tue 26 Jul 2022 | Dorinna Pentchev
Dashboard Week - Accessibility
How I incorporated the concepts we had learnt about building accessible dashboards
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Tue 19 Jul 2022 | Dorinna Pentchev
KPI's and Table Calculations 2: The Wrath of Window Functions
Building a dynamic KPI chart of sales over region with comparisons to prior year, using window functions this time.
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Tue 19 Jul 2022 | Dorinna Pentchev
Making Dynamic KPI's using Table Calculations: part 1
Using table calculations to create KPI's of total sales and percentage changes from prior year, which will automatically update when new data is brought in.
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Mon 18 Jul 2022 | Dorinna Pentchev
Interpreting the results report of a linear regression
What do all of these statistics mean?
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Mon 27 Jun 2022 | Dorinna Pentchev
Connecting to Snowflake Server in Tableau
In this blog, we will learn how to input data into Tableau from the Snowflake SQL server.
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Sun 05 Jun 2022 | Dorinna Pentchev
Including Different Decision Making Scenarios in a Dashboard
An example of how to present potential outcomes of different decisions.
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Tue 10 May 2022 | Dorinna Pentchev
Friendly Neighbourhood Web-Scraper
Revisiting an old project, fixing the web-scraped data with Alteryx this time.
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Thu 05 May 2022 | Dorinna Pentchev
Spatial Data: Finding the Lengths of Routes
Combining Alteryx and Tableau to display London bus routes and their length.
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Sat 30 Apr 2022 | Dorinna Pentchev
Joining tables with different date ranges
Whether you’re joining, blending or relating data, having different dates in both tables may give you some trouble
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Sat 23 Apr 2022 | Dorinna Pentchev
Revisiting the Unique Tool in Alteryx
“This won’t come up on the exam much, right?” Famous last words.
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Mon 18 Apr 2022 | Dorinna Pentchev
Diverging bar charts with consistent scales
In my second week at the Data School, I learnt how to produce a diverging bar chart in Tableau without having to use negative values for one of the axes, and with consistent scaling for both sets of bars
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Thu 14 Apr 2022 | Dorinna Pentchev
Week 2: Makeover Monday but it's Thursday
For this week's project, I chose to rework the viz from Makeover Monday 2020 week 9: Costing Kids Sleep.
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Fri 08 Apr 2022 | Dorinna Pentchev
Joining tables in Alteryx and Tableau Prep
During DS31’s first week of training, we learnt how to join tables of data together in Alteryx and Tableau Prep, which is very useful if you would like to include additional information about records but the corresponding data is in a different data source
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