Internal Operations Tool

SlugTime

Time tracking, payroll, and invoicing for a property maintenance crew. Paper timesheets to automated billing in one build.

6
Techs
39
Properties
12
Billing Entities
~$15.6k
Weekly Revenue
The Challenge

Paper timesheets and manual invoicing at scale

A 6-person crew maintaining 39 properties across 12 different billing entities. Every week: handwritten timesheets, manual hour calculations, and invoices typed one at a time in Word.

The owner couldn't see margins per property. Didn't know which contracts were profitable. Payroll took hours. Invoice disputes had no paper trail. Growth meant more admin, not more revenue.

They needed something that matched how the crew actually worked — not an off-the-shelf app that would require changing their entire process.

The Approach

Built for the workflow

I spent time understanding how the crew actually operated before writing a line of code. The techs needed to log time from their phones between properties. The owner needed payroll and invoices without re-entering data.

The system had to match their existing workflow, not replace it. If it required training or changed their routine, it wouldn't get used.

Google Sheets as the database

Instead of a traditional database, I used Google Sheets as the backend. The owner already lived in spreadsheets. Data was visible, editable, and familiar. No migration needed.

Apps Script handled all the automation — time entry validation, payroll calculations, invoice generation. The frontend was a clean web app deployed on Netlify.

What Was Built
1

Mobile Time Entry

Techs open a web app on their phone between jobs. Select the property, log hours, add notes. Data goes straight to the master sheet. No paper, no end-of-week guessing.

2

Admin Dashboard

Owner sees all logged hours across all techs and properties in real time. Filter by date range, tech, property, or billing entity. Flag discrepancies before they become invoice disputes.

3

Automated Payroll

One button generates the weekly payroll breakdown. Hours per tech, overtime calculations, per-property cost allocation. Exports ready for the payroll service.

4

Invoice Generation

Select a billing period and entity. The system pulls all logged hours, applies contract rates, and generates a professional PDF invoice. Sent directly from the app.

5

Profitability Reporting

Margin per property, cost per tech, revenue by entity. The owner could finally see which contracts were making money and which were losing it.

Tech Stack
GAS

Google Apps Script

Backend automation, payroll, invoicing

GS

Google Sheets

Live database, owner-accessible

H/J

HTML / JavaScript

Mobile-first time entry interface

N

Netlify

Static hosting, instant deploys

DA

Drive API

PDF generation, file management

AI

Claude

Code generation, iteration, debugging

Results

From hours of admin to minutes

What this became

SlugTime proved the model. Track costs per job, automate invoicing, show margins in real time. The concepts worked so well that I rebuilt them as a multi-client platform — QuoteTime. Same core idea, built to scale across different trades and businesses.

See QuoteTime

Running your operation on spreadsheets?

I build tools that turn manual processes into automated systems. Same data, less work, better visibility.

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