DATA ANALYSIS AND AUTOMATION

Reports without the copy-paste. Numbers you can trust.

I help companies and researchers tidy up their data, automate reporting and turn numbers into decisions. You work directly with me — remotely, across the EU.

Free quote · reply within 1 business day · no files needed

DEMOS ON FICTIONAL DATA

Examples of my work

Client data is confidential, so I show the same kind of work on fictional data. The results are calculated from that data — these are not client projects.

Automation · Power Query and VBADemo
Poznań74Poznań: duplicates 7, missing values 10, inconsistent formats 57Łódź69Łódź: duplicates 13, missing values 12, inconsistent formats 44Lublin65Lublin: duplicates 8, missing values 6, inconsistent formats 51Kraków62Kraków: duplicates 9, missing values 11, inconsistent formats 42Wrocław41Wrocław: duplicates 7, missing values 12, inconsistent formats 22Gdańsk36Gdańsk: duplicates 6, missing values 3, inconsistent formats 27Katowice26Katowice: duplicates 4, missing values 4, inconsistent formats 18Warszawa21Warszawa: duplicates 4, missing values 6, inconsistent formats 11

Records with an issue, by branch file

Chart data
BranchDuplicatesMissing valuesFormatsTotal
Poznań7105774
Łódź13124469
Lublin865165
Kraków9114262
Wrocław7122241
Gdańsk632736
Katowice441826
Warszawa461121
Poznań74Poznań: duplicates 7, missing values 10, inconsistent formats 57Łódź69Łódź: duplicates 13, missing values 12, inconsistent formats 44Lublin65Lublin: duplicates 8, missing values 6, inconsistent formats 51Kraków62Kraków: duplicates 9, missing values 11, inconsistent formats 42Wrocław41Wrocław: duplicates 7, missing values 12, inconsistent formats 22Gdańsk36Gdańsk: duplicates 6, missing values 3, inconsistent formats 27Katowice26Katowice: duplicates 4, missing values 4, inconsistent formats 18Warszawa21Warszawa: duplicates 4, missing values 6, inconsistent formats 11

Records with an issue, by branch file

Chart data
BranchDuplicatesMissing valuesFormatsTotal
Poznań7105774
Łódź13124469
Lublin865165
Kraków9114262
Wrocław7122241
Gdańsk632736
Katowice441826
Warszawa461121

Monthly report from branch files

Problem
Every month 8 branches send files in different formats, and the report is assembled by hand.
Data
8 CSV files, 5,547 rows with typical errors: duplicates, missing amounts, mixed date and number formats. The same approach works with .xlsx files.
Work
A Power Query query reads the whole folder, standardises formats and removes duplicates. A control sheet reconciles totals with each file, and a VBA macro saves each branch’s report as PDF.
Result
5,425 valid rows in one table, 58 duplicates removed, 272 entries standardised, 64 records listed for follow-up. Control totals match for 8 of 8 branches.
Tools
Power Query, VBA, Excel

Sample input files: branch file: warszawa, branch file: krakow, branch file: gdansk

Service: Report automation
Dashboard · Power BIDemo

Sales and margin dashboard

Problem
Sales, margin and plan figures sit in several spreadsheets — there’s no single view for management.
Data
12 months of sales in two channels, 10 product categories, plan and actual for 5 regions.
Work
A data model with a calendar, DAX measures (margin, growth, plan vs actual) and three report pages: overview, profitability, regions.
Result
One report that answers: how are sales going, which categories drive margin and which regions are on plan.
Tools
Power BI, DAX, Excel
Service: Power BI dashboards

HOW I WORK

Working with me

Small tasks usually take 2⁠–⁠5 business days, larger projects 1⁠–⁠3 weeks.

  1. 01

    You describe the problem

    A few sentences in the form — no files, no technical spec.

  2. 02

    I reply within 1 business day

    With a few questions or a suggestion for a short call.

  3. 03

    You get a free quote

    Scope, timeline, price and how the work will be accepted — no obligation.

  4. 04

    I do the work

    On copies of your data, under an NDA if you need one.

  5. 05

    You review it and get support

    Files, documentation and a walkthrough of the results. For 30 days I fix issues and answer questions.

How much does it cost?

  • I don’t have a price list — you get the price in a free quote, and it doesn’t change without your approval.
  • For a first order, you pay after accepting the work.
  • Billing goes through Useme, a Polish freelance platform: you get a VAT invoice, and your payment can be held until you accept the work.
  • You can start small, for example with one spreadsheet fix.
Describe your problem

ABOUT ME

You work with me directly.

I’m Hubert Salwa, an applied mathematics engineer with experience in data science, modelling and optimisation. I’ve built models and reporting in insurance — on large datasets, in an environment where every number has to reconcile. Now I help companies and researchers do the same with their data.

What I’ve worked on

  • Statistical and forecasting models on datasets with millions of records
  • Data analysis and data science, including linear regression, canonical correlation analysis and principal component analysis (PCA)
  • Also logistic regression and generalised linear models (GLM), multiple regression, factor analysis, cluster analysis, time series and forecasting, survival analysis, mixed models and panel data, Bayesian methods, anomaly detection, statistical testing, A/B testing and experimental design, and text analysis (NLP)
  • SQL: queries, joining tables and preparing data from databases for analysis and reporting
  • Automated recurring reporting: a dozen sources in one report, with reconciliation checks
  • Optimisation problems such as budget allocation under constraints — always compared with a simple baseline
  • Validating results: reconciling totals to the source, back-testing on historical data, documenting assumptions
  • EducationEngineer’s degree in applied mathematics
  • ToolsExcel, Power Query, VBA, Power BI, SQL, R
  • LocationWarsaw, Poland · working remotely across the EU
  • LanguagesEnglish, Polish

DATA AND NUMBERS

How I handle your data and numbers

I check the numbers before you see them

Before handover I reconcile totals to the source, compare results with the previous period and record what I checked in a control sheet.

Confidentiality

NDA on request, work on copies of your files. We agree together how files are shared — for example a OneDrive or SharePoint folder. If the files you share contain personal data of your customers, employees or survey respondents, we sign a data processing agreement (Art. 28 GDPR) before I start. Shared data is deleted after the project ends.

You own the result

Full rights to the files and code, with no subscription fees. Documentation included, and you talk to the person who does the work — no subcontractors.

BEFORE YOU WRITE

Frequently asked questions

Question not here? Get in touch
Can we start with a small task?

Yes. A single task — fixing a workbook, one macro, a chart for a report — is a good way to try working together before a larger project.

Does the data have to be clean?

No. Cleaning, validating and merging data can be part of the project. A description of your files and sources is enough for a quote.

How does billing work?

I bill through Useme, a Polish freelance platform: you get a VAT invoice. For a first order, you pay after accepting the work. For larger projects a protected transaction is available — Useme holds the payment and releases it only after you accept the work.

How do you invoice companies in other EU countries?

Companies in other EU countries receive an invoice from Useme in EUR, with the VAT reverse charge. Communication, documentation and deliverables can all be in English, and the work is fully remote.

I don’t have a company. Can I still order an analysis?

Yes. Billing through Useme also works for private individuals — you get an invoice in your own name, without needing a company.

Do you help with theses?

I help with statistical analysis and explain the results, but I don’t write coursework or theses for anyone. The conclusions in your work stay yours.

Do you offer Excel training?

Yes, as an add-on: one-to-one sessions tailored to your level and your tasks — from formulas to Power Query and automation, using examples from your own work.

CONTACT

Tell me what’s slowing you down.

A few sentences are enough: what takes too long or doesn’t work, and what you’d like instead. No need to know tool names or send files. I’ll reply within 1 business day.

  1. 1
    A reply within 1 business day, usually with a few questions
  2. 2
    A short call if something needs clarifying
  3. 3
    A quote with scope, timeline and price — no obligation

Prefer to email? hubertsalwa0@gmail.com

LinkedIn profile

ENQUIRY FORM

Request a free quote

Please don’t include confidential data at this stage. The quote is free and there’s no obligation.

Your details are used only to reply to your enquiry and prepare a quote. The data controller is Hubert Salwa. Details: privacy policy.

DEMO · FICTIONAL DATA

Demo

Describe your problem