Web App for Customer Data Storage

My customer data currently lives in separate Excel workbooks, one file per year. This setup has started to feel risky—if a file is corrupted or misplaced I lose everything—so the goal is to migrate all records into a single, secure, browser-based application that can grow with the business.

Core requirements
• Import existing Excel sheets into an online database and keep the original column structure intact.
• Store only customer information for now, but leave room to add other tables later.
• Fast filtering by any column name—date, customer name, purchase history or any new field I introduce. A quick search box plus advanced filters would be ideal.
• Ability to add free-text remarks to individual records without overwriting the original data.
• One-click export back to Excel or CSV when I need a local copy.
• Daily automated backup so accidental loss is no longer a concern.
• Clean, responsive interface that runs well on desktop and tablet.

Technology is flexible; a modern stack such as React or Vue with a Node/Express or Django backend and a relational database (MySQL/PostgreSQL) will work, but I’m open to alternatives if they meet the same reliability and security standards.

Acceptance criteria
1. All historical spreadsheets load successfully, showing identical row counts after import.
2. Filters return results in under two seconds on a dataset of 50,000+ rows.
3. Remarks save instantly and are visible on refresh.
4. Backup file appears in cloud storage every 24 hours without manual intervention.
5. UI passes a quick usability check with non-technical staff.

Source code, brief setup notes, and admin credentials will conclude the project so I can host it on my preferred server or cloud platform.