It means “desk” or “work table” in french, and it’s a blog about interface design.Get the RSS feed.


I'm Thibaut Sailly, an independant interface designer based in Paris. Say hello on mastodon or by email at thibaut ✉ tsailly ◦ net.

Le Baby is an iOS app I made with Amadour Griffais, a shared and private memory helper for parents with newborns. View on the App Store.



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Le Baby - foundations

The design, building and marketing of an object are an endless series of questions.

How should we size this element? Is this the right font for the graphic identity? Can we find a better name for this feature to be instantly comprehensible? Is the price too high? You need to prioritize questions to answer, choose how much time you'll spend to find the best possible answer on each of them, and decide when it's time to move on.

The harmony between the chosen answers is as important for the product perception by its users as their individual relevance to each question asked.

To ensure a minimum of coherence between these decisions and to optimize the time spent on each of them, defining cardinal values for the project and having an objective look at its operational context are helpful guides and accelerators. For this first article of a series about publishing an application on the App Store, I thought it was important to start by listing the facts and principles guiding the decisions we - my colleague Amadour Griffais and I - make for Le Baby.

version française disponible

Ancillary activity

Baby is not our bread and butter, we work on it using the time we have left once we have earned our living. This is probably the most influential condition on the current shape of the app and the way we work on it.

a coffee after dropping the kids at school: a few minutes for Le Baby every day.

Knowing our availability is limited, we have reduced to a minimum the number of channels through which this project can get our attention:

Our collaborative processes are also kept to a minimum: the most concise and infrequent written exchange possible, and occasional meetings to have richer and more subtle discussions. Our involvement in the project varies during the year, it is not constant: sometimes we make a special effort to respect a publication date, but this effort is always made on our free time.

The main influence of this situation on the product is that we pay a lot of attention to the long term stability of what we build. Whether it's the code, the writing of the app description, the preview video on the App Store, or the layout of the press kit, we try to make them modular objects that will only require a small amount of time to accommodate the next functional evolutions of the app.


We have witnessed in our respective professional experiences how financial pressure can sometimes take control of a product definition, leaving the user's benefit or the level of polish in the back seat when deciding what should be done at any given moment.

a nice tree in a meadow bathed by an end of the day sun light

By choosing to build Le Baby with our own resources, and not to call on investors who would have allowed us to work faster, we made sure to keep control over the features the app offers and will offer, their build quality, and the pace at which they are released. Sure, we're moving slowly, and the return on investment is comical for now, but we believe that our current and future users benefit from the choices we've made for the sake of our independence.

For example, there are no trackers installed in the app to measure screen-by-screen usage. We inquire on what our users are doing with the app by talking to those who contact us, or by setting up face-to-face tests - parents with newborns are pretty easy to spot and go talk to, a definite advantage. An unquantified overview that would have been hard to defend to people who had invested money in our project. Perhaps we would have succeeded, but the time used to convince them would not have been put to work for the users.

Another choice we made to preserve our independence, which has already done us a huge favor, is not to use third-party code libraries. Some of them would have sped up the building of certain parts of the app, but Le Baby's compatibility with the new APIs offered by iOS each year would have been dictated by the libraries' compatibility. When we implemented journal sharing earlier this year, we were able to use the last CloudKit developments offered in iOS 15, which allow for encryption of transmitted data. If a critical third-party library had felt that stability on iOS 15 was not a priority for them, we would have had to wait for their update before rolling out this critical feature for parents.


The starting point of this project was the observation that taking notes of a baby's feeding and sleeping habits on a notebook or with existing apps was not very practical. By education or professional distortion, our natural tendency is to run away from everything that is not practical and to look for more obvious alternatives. A very particular attention is therefore naturally paid to the app screens, but also to everything that generates friction in the various project facets (tooling, writing, image production, work files organization).

A public fountain tap on which you can hang the handle of a bucket, so it's not necessary to hold it while it gets filled. Italy.

One choice that influenced the shape of the Le Baby object and was dictated by the search for practicality is the use of the San Francisco font for the app's screens. I had originally selected Avenir Sans to compose the first mockups, but San Francisco ensured that the screens would better fit the scaling managed by iOS. Another example where friction hunting is a permanent concern and has a direct formal influence: the composition of documents intended for the press, emails, press releases, press kits or web page. The recipients attention for these materials can be counted in mere seconds, so ensuring that the message gets through like butter on a hot pan is very important if you hope to be quoted in a press article one day. For Le Baby, this is especially important because we do not intend to use targeted advertising to reach our potential users, for reasons discussed below. We are building the best possible product for parents with newborns, so that their satisfaction can translate into word-of-mouth, and be perceived by the press as a newsworthy topic for their audience.

Digital privacy

We have long been convinced that respecting the privacy of digital products users is important. In building and promoting Le Baby, we have remained true to this principle, even if this has resulted in slower commercial growth. It's more important to us that the users know the information they add to the app never leaves it unless they actively decide so, than to earn more money quickly. This respect for our users privacy has an influence on the construction of the app, its economic model and its marketing.

The handle of an almost closed door

On the building side, we have made sure that by default, the data remains on device, and that it only comes out following an explicit action from the user, each time. It is possible to export the recorded data as a csv file at any moment, and since last April to synchronize it with partners and family. This sharing feature is based on CloudKit, which allowed us to use the highest data protection offered by Apple, and to ensure that only participants can access the information they add (written notes can be intimate) as it remains within their iCloud account. Setting this up is also easier as there's no need to create a “Le Baby” account with email+password. One extremely positive aspect from an operational point of view is that we don't have to manage the servers used for the data exchange. On the downside, when the servers are not working properly, we have no visibility on the restoration timeline, which affects the quality of our customer support.

Adding ad banners to the application would have allowed us to increase the income faster. But users would have lost in comfort because of the screen real estate loss, they would have encountered the occasional mistap making you leave the app, our night mode would not have been as effective as it is today (a banner ad with a light background alone can light up a dark room and disturb the eating baby), and the experience would have simply been less friendly and memorable. We heard from one parent who was thrilled to be using Le Baby again for his second child - not sure if the pleasure of returning would have been the same with banner ads.

In the same vein, no tracker of any sort is installed in the app, and we don't collect any data to resell it to third parties, as some of our competitors do (the Privacy page of the Glow app is quite explicit about it, when you take the time to read it).

For now, we don't have an advertising budget, but we hope that it will come soon. When we'll start our campaigns, we'll choose ad services that do not rely on collecting personal data and building profiles for their operation. It would be dishonest to have a critical point of view on Facebook/Meta, and at the same time giving them money to increase our app's visibility. Disclaimer: we do have an Instagram account, as it seemed sensible to have a presence there two years ago.

Made on site

The last point that guides our modus operandi is that we favor custom-made components when we are able to make them correctly, rather than getting existing but less fitting ones elsewhere to save time.

Home photo studio while shooting stills for upcoming communications

What we build ourselves will always be more accurate to our original intention. Also, as you will have understood by now, we prefer giving ourselves the time to do things right rather than to rush messy things that always end up to slow you down.

When we started working together on Le Baby, the goal was to use this project as a showcase for our respective know-how. The desire to make it a commercial success came later, when we saw that users found real value in using it. But the showcase aspect is still there, and still plays into our decisions.

It obviously takes more time, but the pleasure is there and we are rarely ashamed of the result. On my side, it allowed me to practice writing, staged photography, illustration, and to improve my judgment if not my technique in these areas.

If you have read this far, you have now a good idea of the framework in which the project operates. The next article will get to the heart of the matter by looking at the interface attributes of Le Baby.

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