Spreadsheet to web app
When a spreadsheet has quietly become the system running the business.
I rebuild business-critical spreadsheets as owned software when the workbook has outgrown safe multi-user work, permissions, audit trail, handover or integration.
Problem diagnosis
A spreadsheet can be brilliant until it becomes infrastructure.
- Only one person really understands the workbook, hidden sheets, linked files or macros.
- Multiple people need to edit the process, but version control and approvals are fragile.
- The workbook feeds quotes, schedules, stock, certificates, orders, finance or reports.
The risk is not that Excel is bad. The risk is that a single file now carries business rules, decisions and errors that are hard to inspect.
Responsibility
The job is to preserve the logic, not blindly convert the file.
I work out which parts of the spreadsheet are genuine business logic, which parts are historical clutter, and which parts should stay in Excel for now.
What I would build
The first useful version would be concrete.
- 01
A data model behind the workbook
Customers, jobs, assets, quotes, orders or inspections are represented as records rather than scattered cells.
- 02
Controlled calculation rules
The important formulas and macros are rebuilt with checks around the numbers that drive decisions.
- 03
Role-based screens
People can enter, review, approve and export the right data without editing raw formulas.
- 04
Workflow states
Approvals, exceptions and handovers can become explicit states rather than notes in a cell.
- 05
Imports, exports or integrations
The rebuilt system can feed the tools that need the data without manual copy and paste.
Fit filter
Probably right, probably not.
Probably right when…
- The spreadsheet is business-critical, not just inconvenient.
- Errors or delays have a real commercial consequence.
- People need different permissions, approvals or views.
Probably not me when…
- You need one formula, macro or dashboard fixed.
- A no-code spreadsheet app would solve it well enough.
- You want a template, tutorial or file converter.
First step
Start with diagnosis, not a big commitment.
The first step is to understand the workbook as a business process: inputs, rules, outputs, users and failure points.
£150 per hour plus VAT where applicable. Two hours minimum for new clients. No retainer, no minimum term, no lock-in. You own everything I build.
Useful things to send before a call
- A copy or export of the workbook
- Examples of the reports or outputs it produces
- Known errors and awkward cases
- A list of users, roles and connected systems
Objections
Questions this page should answer before you email.
Can the existing spreadsheet logic be preserved?
The important logic can usually be preserved, but first it needs to be understood, named and tested.
Does everything need to leave Excel?
No. Some analysis and ad hoc work belongs in Excel. The rebuild should target the part that has become operational infrastructure.
Can old spreadsheet data be imported?
Usually, if it is consistent enough or can be cleaned. The first stage should expose that honestly.
Next step
If this looks like your problem, send me the awkward bits.
The useful first email is short: what is breaking, what product or process cannot handle it, and what working would need to mean.