Get unstuck. Build confidence.
Fix a spreadsheet, sharpen a presentation, or learn the Excel and SQL skills you need at work.
Explore the €29 Excel fix ↗ FOR PROFESSIONALS, TEAMS & SMALL BUSINESSES
Your Excel expert.
Your data, sorted.
I’m Martin, a freelance Excel consultant offering spreadsheet fixes, data cleaning, dashboards, and one-to-one online training. Fixed prices. You work directly with me.
Fixed scope & clear pricing Work directly with Martin PayPal payments
16+ yearsIn engineering, data & reporting — across industries.
YOUR NEXT STEP STARTS HERE ↗
What do you need
off your desk?
HELP THAT FITS YOUR WORK
For your next task.
Or your whole team.
Make your data useful.
Clean a customer list, understand sales, and simplify recurring reports with a clearly scoped service.
Explore list cleaning for €49 ↗Improve how work gets done.
Discuss team training, reporting workflows, or a custom application built around your process.
Discuss your team’s needs ↗PRACTICAL HELP. WITHOUT THE GUESSWORK.
What would make work easier?
Pick a result, see what’s included,
and know the price before you start.
10 offers
Work done for youMULTI-BUY ELIGIBLE
Excel spreadsheet repair service. Broken formulas, incorrect totals, or calculation errors diagnosed and corrected. One workbook, fixed price.
- One workbook, up to 3 sheets and 5,000 rows
- Repair up to 3 related formula or calculation issues
€29
Work done for youMULTI-BUY ELIGIBLE
Freelance data cleaning service. Remove agreed duplicates, standardise fields, and flag missing data in your CSV or Excel list. Up to 5,000 rows.
- One CSV or Excel table, up to 5,000 rows and 15 columns
- Up to 5 agreed cleaning rules
€49
Work done for youMULTI-BUY ELIGIBLE
Custom Excel or Power BI dashboard built from your data by a freelance dashboard developer. Sales, costs, or operations in one focused report. Fixed scope.
- One supplied clean table, up to 10,000 rows
- One dashboard page with up to 5 agreed KPIs
€149
Work done for youMULTI-BUY ELIGIBLE
Freelance PowerPoint designer. Turn supplied content into a clear, consistent, professional presentation. Layout, typography, charts, and visual consistency fixed. Up to 8 slides.
- Up to 8 supplied slides
- Layout, typography, chart presentation, and consistency edits
€49
Work done for youMULTI-BUY ELIGIBLE
SQL query consultant. Have a SELECT query reviewed for incorrect results, slow performance, or unnecessary complexity. One query, fixed price.
- One SELECT query using up to 3 tables
- Review with schema and an anonymised sample
€39
Work done for youMULTI-BUY ELIGIBLE
Excel report automation with Power Query. Replace manual copy-paste with one refreshable workflow. Ideal for weekly or monthly recurring reports.
- One Excel report with up to 2 CSV or Excel inputs
- One agreed Power Query refresh workflow
€99
ConsultingMULTI-BUY ELIGIBLE
Talk through one work problem and leave with a short, practical action plan.
- 45-minute focused consultation
- A concise written action summary
€29
Learning packageSAVE ON A PACKAGE
5 live lessons, one structured learning plan. Save €27 compared with individual lesson prices.
- Excel: data entry & clean structure
- Excel: tables & structured references
€78 / person
Save €27 vs. individual lessons
Learning packageSAVE ON A PACKAGE
3 live lessons, one structured learning plan. Save €20 compared with individual lesson prices.
- SQL: SELECT, filtering & sorting
- SQL: joins & table relationships
€57 / person
Save €20 vs. individual lessons
ConsultingMULTI-BUY ELIGIBLE
AI prompt optimization consultant. Get your ChatGPT, Claude, or Copilot prompts reviewed and rewritten against explicit goals and test examples for more reliable results.
- Review of up to 5 related prompts
- Revised prompt templates
€49
A REAL PERSON BEHIND EVERY PROJECT
Hi, I’m Martin.
I connect the dots.
I’m a freelance data consultant and Excel expert with more than 16 years of experience across engineering, data, and business. I build practical tools and solve reporting problems, drawing on operational analytics at Bankers Petroleum Albania and AI evaluation and human data management at micro1.
I hold a Master’s in Petroleum Engineering and am pursuing a PhD. My approach is practical: understand the system, question the assumptions, and build something useful.
Get to know Martin martin.dudumi@gmail.comTHE PROBLEM. THE SOLUTION.
300 before & after examples.
Choose a problem, then switch to After to explore how it can be addressed.
50 examples each
300 examples found · Showing 6
Data analysis
BEFORE · THE PROBLEM
Sales rise but profit falls
This is the issue to resolve. Explore the proposed solution, then discuss how it applies to your files, tools and workflow.
How we solve this
- Understand the inputs
In this teaching case, each row identifies “Product”. Review “Revenue” against “Cost”. Confirm what those fields mean in your own source before applying the same logic.
- Calculate the gap
Subtract the reference value from the input. A negative result shows a shortfall; a positive result shows an excess. Keep both quantities on the same scale.
- Read the result
The first row of the original sample produces:
Item: Product A · Input: 1200 · Reference / assumption: 1100 · Computed result: 100 - Verify before applying
Change one sample input and run again. Check that the result changes as expected, then compare the rule against a known correct case and an exception before applying it to your real workflow.
The runnable example demonstrates this calculation or check. The full solution above may also require source investigation, changes to your files or system, and review of business-specific exceptions.
Try this exampleEditable sample → run → computed result
Editable synthetic teaching case. Reference values are sample assumptions. This models one part of the proposed solution; it does not operate on your files or production systems.
| Product | Revenue | Cost |
|---|---|---|
Change a sample value, then run the demonstration.
The Run button uses the existing browser model. Copy the SQL, Python, Excel formulas or VBA code to run it in its own environment; it is not executed by this page. Input remains in this page.Illustrative problems and proposed solutions, not completed customer projects. The final approach and deliverables depend on your situation.
GOOD THINGS WORK BETTER TOGETHER
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Spend less.
Mix individual lessons, toolkits, and non-app services. Your bag calculates the saving automatically.
App builds and learning packages are excluded. Packages have their own savings. Each different offer counts once. For services marked “from”, the discount applies to the starting budget until the final quote is agreed.
TRY A PRACTICAL LEARNING PACK
3 lessons. One smarter investment.
data entry & clean structureformula foundationspivot tables & pivot charts
Individual total€67
Your pack price€56.95
You save €10.05 · 15% off
Already selected a learning package? The bag will flag any overlapping lessons.ONE GOOD NEXT STEP