Challenge
Two copies of the file disagree, and nobody knows which is right.
Agnotic approach
One database, so every user sees the same record.
Spreadsheet to Web App
Replace Excel with custom software your whole team can use
The workbook that runs quoting, scheduling or stock has grown macros, tabs and copies, and only one person really understands it. Agnotic Technologies turns it into a custom web app with one database, user logins, an audit trail and the same calculations your team trusts.
Workbook auditOne shared databaseRoles and audit trailExcel import and export
Trusted by global innovators
What does it take to replace Excel with custom software?
Replacing Excel with custom software means moving a business workbook into a web app with a real database, screens built for each role, user logins and permissions, and the formulas rewritten as tested code. Agnotic Technologies starts with a workbook audit that maps every tab, formula, macro and manual step, then builds the app so people enter data once and everyone sees the same numbers. Excel stays where it is useful: users can still import a sheet or export a report. The app runs beside the workbook until the results match, and only then does the team switch over.
Decision table
When should we replace our Excel sheets with custom software?
Replace a workbook when several people depend on it at once, when a mistake in it costs real money, or when it has to exchange data with other systems. Keep Excel for personal analysis and one-off reports.
| Signal | What it looks like | Our usual advice |
|---|---|---|
| Several editors | People email copies around or wait for someone to close the file | Replace: a web app gives everyone one live copy |
| Business rules in macros | VBA that one person wrote and nobody else edits | Replace: the rules move into tested code |
| Data typed twice | Values copied by hand from the ERP or another sheet | Replace or integrate: pull the data through an API |
| Access matters | Prices, pay or customer data visible to anyone with the file | Replace: roles decide who sees and edits what |
| History matters | Nobody can say who changed a number, or when | Replace: an audit trail records every change |
| One person, one analysis | A model you build, read and change yourself | Keep Excel |
| A monthly report from clean data | A pivot table refreshed from an export | Keep Excel, or add a dashboard |
Workbook to web app
Can you turn our Excel workbook into a web app the whole team can use?
Yes. We rebuild the workbook's data, formulas and steps as a web app with logins, and we prove it gives the same answers before anyone stops using the file. This is how the move happens.
Workbook audit
We map every tab, formula, macro, lookup and manual step, and who uses each one.
Data model
Tabs become tables with keys and rules, so the same customer or part exists only once.
Formulas as tested code
Calculations are rewritten, and the workbook's own results become the test cases.
Screens per role
Each role gets the screens it needs, instead of one sheet that shows everything.
Import and parallel run
Current data is imported, and the app runs beside the workbook until the numbers match.
Switch over
The workbook becomes read-only and the team works in the app, with export still available.
Build or buy
Should we build an internal tool or buy another subscription?
Buy when a product already fits your process with settings alone and your team is happy to work its way. Build when the process is what sets your business apart, when it spans systems no product connects, or when a subscription would need so many workarounds that a spreadsheet grows back beside it.
Agnotic Technologies gives a straight answer on the scoping call. If an off-the-shelf product fits, we say so, and we can help connect it to your other systems instead.
Failure points
What breaks when a workbook runs the business?
The problems that usually start the conversation, and what the web app changes.
Challenge
A formula was overwritten and the totals have been wrong for weeks.
Agnotic approach
Calculations live in code with tests, and users cannot overwrite them.
Challenge
The person who wrote the macros has left.
Agnotic approach
Documented code in your own repository that any developer can maintain.
Challenge
Sheet protection is treated as security.
Agnotic approach
Logins and roles control who sees and changes each record.
Challenge
Nobody can explain last month's change.
Agnotic approach
An audit trail records who changed what, and when.
What goes into a custom internal tool?
Custom internal tools development covers more than screens. These are the parts we build.
Data model and database
Tables, keys and validation rules replacing tabs and lookups.
Screens for each role
Entry forms, lists and approvals for the people who use them.
Calculations as tested code
Pricing, scheduling and stock rules with tests built from your workbook.
Excel import and export
Bulk import of sheets and export of any list or report.
Approvals and notifications
Requests routed to the right person, with reminders when they wait.
Integrations
ERP, CRM and accounting systems connected through their APIs.
Logins, roles and audit trail
Single sign-on with your identity provider and a record of every change.
Reports and dashboards
The totals people used to build by hand, kept current.
Where it starts
Workbooks we often replace
Business workbooks that outgrew a single file.
Quoting and pricing
Price builders with margins, discounts and approval rules.
Production and staff scheduling
Shift and job plans that several supervisors edit at once.
Inventory and stock
Stock counts and reorder points copied in from other systems.
Project and job tracking
Status, hours and costs per job, reported to managers.
Commission and bonus
Calculations that pay people and must be explained.
Registers and logs
Compliance, asset and contract registers with owners and dates.
Facts and sources
What Microsoft and OWASP say about the move
Vendor documentation on Excel's limits and the security standard we build web apps against, each linked to its source.
Microsoft lists the maximum Excel worksheet size as 1,048,576 rows by 16,384 columns.
Source: Microsoft Support, Excel specifications and limitsMicrosoft states that worksheet level protection in Excel isn't intended as a security feature: it only prevents users from modifying locked cells in the worksheet.
Source: Microsoft Support, Protect a worksheetMicrosoft labels Excel's Shared Workbook feature as legacy, says it has many limitations, and recommends co-authoring as its replacement.
Source: Microsoft Support, What happened to shared workbooks?The OWASP Application Security Verification Standard (ASVS) provides a basis for testing web application technical security controls and gives developers a list of requirements for secure development.
Source: OWASP, Application Security Verification Standard
Standards
Which standards do we build internal tools to?
OWASP ASVSWCAG 2.2OpenID ConnectOpenAPIXLSX and CSV
Scope
What decides the size of the build?
We do not publish prices. These are the drivers we size on the scoping call.
Workbook size and macros
How many tabs, formulas and macros carry business rules.
Users and roles
Who uses the app and what each role may see or change.
Integrations
Systems the app reads from or writes to, and their APIs.
Data migration
How much history moves across, and how clean it is.
Reports
Built-in reports, or data sent to your BI tool.
Hosting
Your cloud account or ours, and your sign-on provider.
Engagement
How does a spreadsheet replacement project run?
We start with the workbook itself.
1.
Scoping call and workbook review
You share the workbook and walk us through a normal week of using it.
Scope2.
First release
A fixed-scope first release covering the core tabs, roles and calculations, run beside the workbook.
Build3.
Switch over and extend
The team moves to the app, then we add integrations, reports and the remaining tabs, with support after launch.
ScaleFrequently Asked Questions
Yes. Any list or report can be exported, and bulk data can be imported from a sheet. Excel stays a tool for analysis; it just stops being the system of record.
That is how we test it. The workbook's own results become test cases for the rewritten calculations, and the app runs beside the workbook until both agree.
We read them, document what they do, and rebuild the rules that matter as tested code. Macros that only format or copy data usually disappear because the app does that work.
Yes, through the APIs those systems offer. Data that was copied in by hand is read directly instead, and results can be written back where the system allows it.
Sometimes. If a low-code platform you already license fits the process, we say so on the scoping call. Custom code fits better when rules are complex, integrations are many or you want to own the code.
We do not publish prices. Workbook size, users and roles, integrations, migration, reports and hosting decide the size, and we agree a fixed first release on the scoping call.