From 16-hour monthly ordeal to 3-click payslip delivery — how one coaching network got its Mondays back
A 200+ employee coaching network was spending the better part of every payday manually generating, encrypting, and emailing individual payslips. L'inno built Sheldon Sender. Now the same process takes three clicks and completes in under eight minutes.
- Time saved on payslip delivery
- 96%
- Employees served each month
- 200+
- Full distribution time
- <8 min
- Manual errors since launch
- 0
The challenge
Blue Dragon Children's Foundation is a Blue Dragon Children's Foundation is one of Vietnam's most recognised NGOs, working to rescue and rehabilitate children from poverty, trafficking, and exploitation in Hanoi and across the country, with over 200 employees ranging from full-time coaches to part-time administrative staff. Every month, the HR manager faced the same Monday: an entire morning blocked out for payslip delivery. The process was entirely manual. Payroll data lived in a Google Sheets master file. For each employee, the HR manager would: 1. Copy the employee's pay data into a Word template 2. Export it as a PDF 3. Password-protect the PDF using each employee's personal ID number 4. Attach it to an individual email addressed to that employee 5. Send it — and repeat for the next employee With 200+ employees, this consumed a full working day. A single mistake — wrong password, wrong attachment, wrong recipient — required finding and re-sending the correct document, often under pressure from the employee asking where their payslip was. There was no audit trail, no delivery confirmation, and no way to know whether an employee had received their payslip unless they replied to confirm. The HR manager had raised the issue internally multiple times, but no off-the-shelf payroll software supported the combination of Vietnamese payslip formatting, password protection with personal ID keys, and email delivery at a price the organisation could justify.
What we built
L'inno built Sheldon Sender — a web application that sits on top of the existing Google Sheets payroll workflow, requiring no change to how the HR team currently manages payroll data. **Input: the existing spreadsheet.** The HR manager uploads the monthly payroll Google Sheet (or exports it as XLSX) directly into Sheldon Sender. The system reads employee names, email addresses, personal ID numbers (used as PDF passwords), and pay line items automatically. **PDF generation.** Sheldon Sender generates a formatted payslip PDF for each employee using a template configured to match the client's existing payslip layout. PDFs are generated server-side in parallel — all 200+ documents are ready within seconds. **Password protection.** Each PDF is encrypted with a 256-bit AES password derived from the employee's personal ID number — the same convention the HR team was applying manually, now applied automatically and without error. **Email delivery.** The system sends each encrypted PDF to its recipient via the company's email domain. The subject line, greeting, and body copy are configurable. Sheldon Sender tracks delivery status for each email and displays a live send log. **Dual-channel delivery.** For employees who prefer Zalo (Vietnam's dominant messaging app), Sheldon Sender can simultaneously send a Zalo message with the payslip attached, using Zalo's official API. **Audit log.** Every send event is logged with timestamp, recipient, and delivery status. The HR manager can see at a glance who has received their payslip and who hasn't — without chasing replies. Sheldon Sender is now a standalone SaaS product available to any Vietnamese business facing the same problem.
The result
The first fully automated payroll run completed in under eight minutes. The HR manager spent that Monday on actual HR work for the first time in years. The improvement is not just in time saved. The manual process carried real risk: a misfiled PDF, a wrong password, a misaddressed email — any of these could expose one employee's salary data to another. With Sheldon Sender, each PDF is generated and addressed programmatically from the same source of truth, eliminating the class of errors that come from copying and pasting. The audit log has been particularly valued by the finance team, who can now confirm delivery as part of the monthly payroll close rather than relying on the HR manager's memory of who had replied to confirm receipt. Sheldon Sender has since been adopted by additional clients facing the same problem. The platform now processes payslips for several organisations across Vietnam each month.
Technologies used
Next.js (frontend + server actions), Node.js (PDF generation with pdf-lib), 256-bit AES encryption, Google Sheets API, Resend (email delivery), Zalo Official Account API, PostgreSQL (audit log), deployed on Vercel.
“It's been a game-changer for our payroll process. What used to take us an entire day of manual work now takes minutes with just a few clicks. Plus, we have peace of mind knowing there are no more errors in delivery or password protection. Our employees have been thrilled with the new system.”
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