Designing file discovery around how people actually remember

Every team that used MelpApp had the same quiet ritual: scroll up. Someone shared a file last week, the conversation moved on, and now finding it means combing back through hundreds of messages — or just asking them to send it again.

MelpApp combined messaging, calls, and workspace chat — an early-stage enterprise product already live inside around 150 companies, with ten to fifteen people on each team living in it every day. Files rode along inside conversations, which felt natural until a thread got long. Then the document you needed was somewhere in there, unsearchable, often re-uploaded two or three times by people who couldn’t find the original. The product had quietly become an archive of files without ever becoming a system for managing them.

When the chat becomes a filing cabinet

The behaviour was everywhere once I looked for it. People didn’t lose files because the app lacked a feature — they lost them because the app’s only model for a file was “a thing that happened in a conversation.”

What people kept telling us

I interviewed teams who lived in MelpApp daily — designers, engineers, managers. The pattern was consistent, and a little obvious in hindsight.

Once a document had been shared, people expected to find it on its own terms — by what it was, who sent it, when — not by reconstructing the conversation it came from. That single observation moved the problem from “improve message history” to “give files a home of their own.”

The decision: a workspace, not a folder

The easy answer was a conventional file explorer bolted onto the side. I didn’t want that — a separate folder tree would just split people’s attention between “where I talk” and “where my files live.” The harder, better answer was a workspace that connected the two, so a file kept its conversation context and gained a life beyond it.

This dual model became the spine of the product. Files grouped by conversation preserved the why; the same files in a structured workspace served the people who think in folders. Nobody had to choose, and nothing was stored twice.

Selling a model that sounded like a cost

The dual model was elegant on a diagram and alarming in a founder’s head. The first objection was money: “storing every file in two places will multiply our storage bill.” It was the right instinct and the wrong reading — the point was that there was only ever one file. Upload it from any channel and it stays a single canonical copy; by conversation and by workspace are just two lenses onto it, never a second copy.

Engineering pushed back next, on effort — two surfaces sounded like twice the build. The reframe that moved them was the same one: one storage path, two visibilities, not two systems. And the argument that finally landed wasn’t architectural, it was commercial — this was the change most likely to lift retention, because people would stop losing their own work inside the product.

So we didn’t bet the whole product on it. We shipped to one set of companies first, watched the numbers, and rolled out to everyone only once the results held. Leading a team of five designers alongside the PM and the founder, I spent as much of this project defending the model as drawing it.

Designing the rest around how people look

With the model settled, the direction was clear — but the two features that carried it, permissions and search, were the hardest things to get right, and the hardest to get built.

A personal workspace let people upload and organise without posting into a chat, then drop a file into any conversation by reference — killing most of the duplicate uploads. Permissions were the fiddly heart of it: the same file could enter one chat read-only and another with download rights, owner-controlled per place it landed — so a shared document stopped changing under the people who depended on it. And search took the most convincing: the vast, multi-filter search people actually needed was real engineering cost, and I had to argue it wasn’t a nice-to-have but the entire point of giving files a home.

What changed

Giving files a home of their own changed how — and how often — teams used the product.

The numbers tracked something simpler underneath: people stopped losing their own work, and a collaboration tool started feeling like one.

What I took from it

The instinct was to make message history smarter. The unlock was to stop treating files as a side effect of conversation and start treating them as first-class objects with their own home.

It taught me to design for the mental model, not the data model. People had told us, plainly, that they thought in files — the product just hadn’t been listening. But the model was only ever the idea. Everything hard came after: carrying it past the people who had to pay for it and build it, and proving with real numbers that the bet was worth making.

Engagement and retention come from Firebase, measured before vs. after the file workspace shipped — engagement as overall product activity, retention as company and user churn and the share of people who moved into the workspace and stayed. The workspace was the primary release in that window.