Case study · AI engineering

LeBread Ops

A Telegram assistant for staff admin at LeBread, a bakery café in Bern.

The problem

Overtime lived on a paper sheet. Every month the manager went through it by hand and checked the hours. That took about 4 hours.

What it does

Staff use it in Telegram. They can:

  • log their working hours
  • swap shifts
  • report sick
  • request days off

Admins approve requests in the same chat.

Monthly statements are saved to Google Drive as PDFs.

Shifts and hours sync to Google Calendar and Sheets.

Reminders go out on schedule, and the database is backed up every night.

The design rule

The AI chooses. The code does the work.

The language model reads the chat and only picks which tool to call. Pay and hours are calculated in plain Python and SQL. Any change to the data is a proposal, and a person confirms it before it's saved. The monthly reports run with zero AI calls.

Diagram: a Telegram message goes to the LLM, which picks a tool. Python functions do the work and write to SQLite, Google Calendar, Sheets, Drive and PDF. Changes to data wait until a person confirms them. Telegram LLM picks a tool Python functions Person confirms SQLite Google Calendar Sheets Drive PDF

How a message moves through the system

The LLM only picks the tool. Python does the maths, and a person confirms every change to the data.

Numbers

saved on overtime checks (measured)
4 h/month
AI cost per request vs v1*
−90%
automated tests
1,700+
test coverage
99%

AI cost per request

Bar chart: cost per request, v1 at 100 and v2 at about 10, roughly 90% lower. Early numbers. v1 100 v2 10

Relative cost, v1 = 100.

* Cost per request: early numbers, being measured.

Code

The code belongs to a client project and stays private. I'm happy to walk through it in an interview.

Next case study: Garage data lake