Look for coordination problems, not row count
A large spreadsheet can be perfectly manageable for one specialist. A smaller sheet can be risky if several people edit it, copy it, email versions around or depend on colour and comments to understand what happens next.
Separate data from workflow
Before designing replacement software, identify which fields are facts, which formulas are business rules, which columns represent status and which actions people perform outside the sheet.
That analysis often reveals that the real product is a workflow application with a table inside it — not simply a prettier spreadsheet.
Add permissions where responsibility matters
Custom software can make editing and approval rights explicit. A user may be able to create a request, another to approve it and an administrator to correct configuration without everybody receiving unrestricted access to the same file.
Automate repeated hand-offs carefully
Notifications, generated documents, API calls and status changes can remove manual steps, but automation should follow a clear process. Automating an ambiguous workflow only makes mistakes happen faster.
Plan migration as part of the product
Existing spreadsheet data often contains duplicates, inconsistent values and historical shortcuts. Migration should define which data is worth carrying forward, how it will be cleaned and how the new system will prove that important records arrived correctly.