Business analyst · Analytics & BI

Turning business data into clearer decisions.

Hi, I’m Guilherme. I use analytics, reporting, and workflow automation to help teams spend less time fighting spreadsheets and more time acting on the right information.

SQL + BIFrom raw data to usable reporting
80% less manual workProcess-automation track record

Projects

Analytics and automation work.

A mix of public portfolio work and anonymised real-world case studies, focused on making business data easier to understand and use.

Illustrative regional bus service analysis showing passenger demand by departure and route performance

Transport service analysis

From transaction data to service-level performance insight.

SQL MySQL Power BI DAX CTEs & window functions

Built a six-page synthetic-data case study covering network demand, fare revenue, recurring services, booking behaviour, timetable effects, origin-destination flows, and a weekday-departure heatmap.

  • Analysed 484,230 transaction records at the correct grain, using passenger totals and distinct journey counts to measure demand per service.
  • Used CTEs, window shares, and dense ranking to separate high-demand departures from high-value revenue services.
  • Published the documented SQL, synthetic dataset, Power BI dashboard, and final report screenshots in a reproducible case study.
Illustrative airport transfer and local taxi service analysis showing weekly bookings and cancellation risk

Transport service analysis

What changed after a modelled taxi-service launch?

SQL MySQL Power BI DAX Data storytelling

Built a synthetic-data case study that uses SQL and Power BI to assess service mix, route movement, cancellation risk and acquisition-source quality around a modelled Local Taxi launch.

  • Used four equal 21-day comparison windows and daily normalisation to avoid treating a pre-launch peak as baseline performance.
  • Found Airport Transfer revenue per day 18.1% below the pooled baseline, with Airport-to-West-Cork journeys driving most of the decline.
  • Separated cancellation frequency from booking-value impact, then prioritised Meta Ads and Taxi Google Ads as diagnostic follow-up areas.
Illustrative coffee shop sales analytics dashboard showing revenue trend and store performance

Coffee shop sales analysis

From SQL exploration to a published Power BI report.

SQLMySQLPower BIDAX

Built an end-to-end analysis of roughly 149,000 transaction records across three New York coffee shop locations, starting with SQL EDA and finishing with a three-page interactive Power BI report.

  • Validated the data grain and replaced an unsupported AOV assumption with Average Transaction Record Value.
  • Used CTEs, window functions, ranking, and DAX filter context to analyse stores, products, trends, and holidays.
  • Published the report and documented the full analytical process, including mistakes, limitations, findings, and recommendations.
Illustrative Olist e-commerce dashboard with sales trend and category comparison

Olist e-commerce analysis

From transactions to commercial questions.

SQLTableauData cleaningKPIs

Built a clean analysis layer and Tableau dashboards to explore GMV, orders, customer growth, repeat purchase share, and category and product performance.

  • Prepared raw transactional data for consistent reporting.
  • Created executive and commercial dashboard views in Tableau.
  • Explored customer acquisition, retention, and product performance.
Illustrative workflow showing sales data flowing through validation into operational planning

Confidential internal project

Operational data & sales automation.

Google Apps ScriptWooCommerce APIData validationProcess automation

Mapped a manual operational reporting process and built a scheduled Google Sheets automation that ingests sales data, validates operational updates, and supports reliable route-planning panels for an event transport operation.

Designed the workflow around a structured ledger, controlled event inputs, cancellation checks, and safe rebuilds—improving the consistency and recoverability of planning information.

Impact: Reduced a recurring manual update workflow by approximately 80%, from around 9 hours to under 2 hours per month, with greater operational benefit during high-volume periods.

Operational details, figures, and system screenshots are intentionally anonymised.

Illustrative sales and customer performance dashboard with trends and customer segmentation

Confidential internal project

Sales & customer performance analytics.

ExcelPower QueryPivotTablesInteractive slicers

Built a structured Excel reporting model to turn several years of sales data into a clear view of demand, seasonality, customer behaviour, and event performance.

Prepared and transformed the data with Power Query, then created KPI views, charts, PivotTables, and interactive filters for practical exploration of the 2023–2025 reporting period.

Business value: Made it easier to compare event performance, identify busy and quiet periods, and distinguish new-customer acquisition from repeat-customer activity.

Commercial data and dashboard visuals are intentionally anonymised.

Expertise

Skills used to turn data into useful work.

A practical toolkit across analysis, data quality, reporting, and operational automation.

Analysis & reporting

Turning raw data into clear answers, KPI views, and decision-ready reporting.

SQLPower BIDAXExcelPower QueryTableau

Data quality & process

Improving the reliability of operational information before it drives a decision.

Data cleaningValidationKPI designData storytelling

Automation & operations

Removing repetitive spreadsheet work while keeping everyday business processes dependable.

Google SheetsApps ScriptAdvanced formulasAPI integration

About me

Business-minded analytics, grounded in real operations.

Hi, I’m Guilherme, a Business Analyst focused on turning everyday operational information into clearer answers and better decisions.

My background in customer-facing and operational roles has shown me how much time businesses lose to manual processes, scattered spreadsheets, and reporting that does not answer the real question. That is where I like to work: understanding the process, improving the data, and making the result useful to the people running the business.

I bring a practical toolkit across SQL, Power BI, DAX, Tableau, Excel, Google Sheets, reporting automation, and data quality—always with the business context in mind.

Get in touch

Have data, a reporting problem, or an analytics role to discuss?

Contact me