# The building of Oasys, in the open. The Diary is the Oasys build log: notes from the people doing the building about what went in, what came out and what we learned. It is updated when there is something to say, not on a fixed calendar. - **Entries published:** Six - **Published between:** 18 March 2026 and 22 April 2026 - **Written by:** The Oasys team - **Cadence:** When there is something to say, not on a fixed calendar ## What the diary is Notes from the people doing the building. What went in, what came out, what we learned. Updated when there is something to say, not on a fixed calendar. Entries run newest first, and each one has its own page. Every entry so far is signed by the Oasys team and runs to about two minutes of reading. ## Shipped: bill splitting by percentage. Published 22 April 2026. At customers' request. And they were right. Four friends at a table: the one drinking double pays 30%, the one who ate little pays 15%. Splitting by percentage is now built in. It is not going out to everyone yet. We are running it with five houses for two weeks before releasing it generally. ## Pulled: the kitchen display turbo mode. Published 15 April 2026. We launched a mode in the kitchen display that squeezed the time between stations. It worked in the test house, it failed in three real kitchens. Dishes started to burn. We removed it. The lesson: time in the kitchen is not a software bottleneck, it is a heat bottleneck. The next version respects the time the grill takes, it does not try to speed it up. ## This week went into production. Published 8 April 2026. Four things reached production that week. - Offline mode on the point of sale. It works for up to 4 hours with no network. - Integration with the Toledo Prix III, a bakery scale. - Grouping tabs onto a single table. NFC wristband plus table. - Commission report per waiter, exportable as CSV. ## What we learned in Q1. Published 1 April 2026. We closed the quarter with 47 houses running Oasys in Sao Paulo. Three lessons that changed the direction of the build: One. A bakery operates in four shifts, not one. A system designed for a restaurant breaks at the display case. Two. The bar's wi-fi goes down. Always. Anything that depends on the network has to work offline, or it does not work. Three. A waiter does not read a manual. The interface has to be obvious in fifteen seconds. Or he goes back to the notepad. ## Why we do not have a free plan. Published 25 March 2026. The question came up again this week, so it is worth writing down. A free plan does not fit our model. Not because we want to charge a lot. Because support for a real operation costs a lot for whoever offers it. A house shut on a Friday because the system froze is our nightmare. To avoid it we keep someone on call until midnight, every day. A free plan would mean email support within 48 hours. And that breaks the customer's operation. We charge monthly, with no lock-in and no penalty. Anyone who does not want to stay leaves the same day. ## Shipped: NFC on the wristband. Published 18 March 2026. A customer of Bar do Zé suggested it, three other houses asked for it. The NFC wristband opens a tab on the way in, records every order at the counter and at the tables, and closes it on the way out. It works with disposable paper wristbands and with reusable silicone ones. It fits the flow of a packed standing bar. Nobody has to chase a waiter to open a tab any more. ## See also - [Shipped: bill splitting by percentage](https://oasysai.com.br/diario/divisao-conta-porcentagem) - [Pulled: the kitchen display turbo mode](https://oasysai.com.br/diario/modo-turbo-kds) - [This week went into production](https://oasysai.com.br/diario/esta-semana-em-producao) - [What we learned in Q1](https://oasysai.com.br/diario/aprendemos-q1) - [Why we do not have a free plan](https://oasysai.com.br/diario/por-que-nao-plano-gratis) - [Shipped: NFC on the wristband](https://oasysai.com.br/diario/nfc-na-pulseira) - [Insights](https://oasysai.com.br/insights) - [Plans and pricing](https://oasysai.com.br/planos) --- This is the English markdown representation of https://oasysai.com.br/diario. The rendered page is in Brazilian Portuguese and is the authoritative version.