Replace the spreadsheet that became critical infrastructure.

Signs the spreadsheet has outgrown itself:

• More than 5 people edit it
• It has 10+ tabs and counting
• Someone built complex formulas that “only [name] understands”
• Conditional formatting is doing the job of a database
• You’re afraid to change anything
• “Spreadsheet broke” is a sentence you’ve said recently
• You wish there was an undo for accidental edits
• You wish you could control who edits which fields
• The spreadsheet syncs (or should sync) with another tool

If 4+ are true, treat it as critical infrastructure.

• A real data model — tables with relationships, validation, types.
• Permissions — roles control who can see, edit, or delete. Audit trail.
• Validation and rules — status transitions enforced. Business rules enforced.
• A familiar interface — Airtable Interfaces or Retool grid: looks familiar with safety.
• Integrations — the system connects to your CRM, accounting, file storage.
• Migration — every row migrated with mapping, deduplication, and cleanup.
• Documentation — methods document + Loom walkthroughs.

Mostly tabular, 5–20 users → Airtable + Airtable Interfaces. Heavy logic, technical maintainers → Retool + Postgres or Supabase. External users involved → Bubble or Next.js. 5,000+ rows with real performance needs → custom Next.js + Supabase.

A 22-person agency tracked all client work in a Google Sheet with 18 tabs and 9 contributors. We built an Airtable + Airtable Interfaces system with roles, status workflow, two-way sync, audit log, and automatic Monday digest. Migration took 3.5 weeks; parallel run for 2 weeks. Time spent on “fix the spreadsheet” went from 4–6 hours/week to about 30 min/week.