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Case 02 · In-house product

Neta

Eleven years of spreadsheets, replaced in 74 days.

In use
Personal financePWA with AIPrivate by design
A recreated monthly spreadsheet, with a sum that leaves out one row
The spreadsheet, recreated: the highlighted error shows the kind of error, it isn't one of the 5 real ones. Sample data.

The case

From three spreadsheets to one app.

Context

An in-house personal finance product, used by 20 to 25 people.

Problem

Eleven years of finances in three hand-filled spreadsheets, with sum errors nobody noticed.

Solution

An installable app: you type or dictate an expense, AI suggests the details and the person confirms. It handles card instalments, two currencies and a budget.

Result

11 years of spreadsheets migrated to the cent, with 5 hidden errors found. In production in 17 days.

Scope

Ten features, no spreadsheet.

Entry by text, voice or form

The expense goes in on the spot, in three taps.

AI completion

AI suggests the category and details from the note.

AI suggests, the person confirms

Nothing is saved without someone seeing it.

Monthly summary

Net, by group and by category.

A budget that builds itself

From the previous month.

Cards and instalments

What's due on the next statement.

Shared projects

Who owes whom.

Pesos and dollars

Each currency with its own total, never mixed.

Recurring expenses

They show up on their own; they count once confirmed.

Passwordless sign-in

You sign in with an email.

Principles

AI suggests, the person decides.

Whatever AI filled in stays labelled until the person confirms it with a tap.

Private by design.

Each account sees only its own, enforced by the database; AI runs locally, with no third parties.

Eleven years, to the cent.

The migrated spreadsheets matched to the cent and 5 hidden errors surfaced.

How it was built

In production in 17 days.

  1. 29 Jul Research and decisions
  2. 1 Aug First commit
  3. 18 Aug In production
  4. 25 Aug First usable version
  5. 6 Sep 11 years migrated
  6. 12 Sep AI in production
  7. 20 Sep First outside users
  8. 14 Oct Spreadsheets replaced

Walkthrough

From dictating an expense to the budget, in five steps.

  1. The screen for dictating an expense, with the microphone on and the timer running
    01 Dictate the expense

    The way you'd say it to someone.

  2. The dictated note written out, with the fields AI filled in labelled
    02 Review

    What AI filled in, labelled.

  3. The monthly summary with the new expense added to the net
    03 See the month

    The expense already counts in the net.

  4. Each group with spending against the budget
    04 Against the budget

    Spent versus planned.

  5. The month's budget proposed from the previous month, ready to review
    05 The budget, built for you

    From the previous month.

Gallery

Everything else it handles.

  • A card and its next statement: what's due, when it closes and which instalments are included
    Cards and instalments

    What's due on the next statement.

  • A fund shared by three people, showing who owes whom
    Shared funds

    Who owes whom.

  • Monthly recurring expenses waiting for confirmation
    Recurring expenses

    They show up on their own; they count once confirmed.

  • The monthly summary in dollars, with its own total and categories
    Pesos and dollars

    Each currency with its own total.

  • The sign-in screen with an email field and no password
    No password

    You sign in with an email.

All screenshots show sample data.

Next step

Tell me how your company works.

The first step is an Operations X-ray: a process map, prioritized pain points and a closed scope.

Message me on WhatsApp

Software comes second.

WhatsApp +54 9 3464 529826 Email esequiel.milazzo@gmail.com LinkedIn linkedin.com/in/esemilazzo