Most products arrive finished, with the seams hidden. We want to do the opposite. Meridian is a private personal AI that holds the whole of you in one place, your body, your emotions, your experiences, your relationships, your growth, and reflects the patterns back. A mirror that learns. Building something that intimate in secret felt wrong. So each week we will write down what we built, what the research is teaching us, and where it is going next.
Some weeks will lean toward the engineering. Some will lean toward the science. All of them will be honest about what is done and what is still rough.
What we shipped this week
The work this week was about foundations: the parts a reader never sees, but feels later as trust.
- The first version of the site went liveThe home page, the manifesto, and our privacy, terms, and cookie pages are all up. The privacy stance is not a footnote for us, so it shipped alongside the front door.
- Groundwork for connecting your data, privatelyWe started wiring the plumbing that will let Meridian read from sources like a watch or a ring, with the design rule that your data stays yours. Early and unglamorous, but it is the spine of the product.
- A clearer architecture for modeling the whole selfWe firmed up how the five life domains fit together into one model rather than five disconnected trackers. This is the idea the whole product rests on.
None of this is the finished experience. It is the quiet scaffolding that everything visible will stand on.
What the research keeps reminding us
One finding sits behind a lot of what we are building. Sleep and mood do not run on separate tracks. They move together, and they move in both directions: a short night can flatten the next day, and a heavy day can cost you the night that follows.
Every reading is precise. Not one of them is connected.
That is the gap Meridian is built for. Your watch knows the short night. Your notes might hold the heavy day. But the two never meet, so the explanation that ties them together never gets assembled. Holding both in one place, privately, is the whole point. The science here is real and we hold ourselves to citing it honestly: the bidirectional link between sleep and mood is documented in the research literature, including work by Kouros and colleagues (2022) and by Vandekerckhove and Wang (2018). We will keep drawing on that evidence base, and we will keep naming our sources.
Where this is going
Next, we turn the foundations into something you can feel: the first private connections to your own data, and the earliest version of the reflection that makes Meridian a mirror rather than a dashboard. We are also continuing to write up the research that underpins the product, and we will share pieces of it here as it takes shape.
We are building deliberately, not fast for the sake of fast. The aim is something calm and trustworthy, the opposite of optimization culture. The beta is live now, by invite, and the best way to follow along is to request access and read these notes each week.
Written by Davide, Founder of Meridian.
References: Kouros et al., Bidirectional Associations Between Nightly Sleep and Daily Mood, Child Development (2022). Vandekerckhove & Wang, Emotion, Emotion Regulation and Sleep, AIMS Neuroscience (2018).