Cero began as a design brief from a friend, built around one question: how can Americans be more conscious about the waste they throw away? I could be as imaginative as I liked with hardware and software, with one firm rule: the technology had to exist today, or be ready for market within six months.

Every day, we make dozens of small decisions about waste, and every one of them disappears the moment the lid closes. We track our steps, our sleep, our spending. Waste is one of the few habits we never get to look back on.

My answer was Cero: a camera above the bin that identifies what you throw away, a smart plate beneath it that weighs it, and an app that turns both into gentle feedback. Not guilt, not more effort, just a way to help families live lighter, one small choice at a time. Four principles guided the work: Clarity, Control, Care and Cycle.

Before any interface, I started with a feeling. What does it feel like to throw something away?

Mostly, it feels like nothing. A banana peel, a bottle, a takeaway box: gone, without a second thought. The average American throws away around 4.9 lb of waste a day, and almost none of it is ever seen again. Out of sight, out of mind. And you can’t change a habit you can’t see.

These things stood out to me:

• Visibility changes behaviour. Step counters and spending apps don’t lecture anyone. They just show you, over time, and people adjust on their own.
• Smart bins solve a different problem. Most focus on convenience, like touchless lids and sealed bags. They don’t tell you what you threw away.

That was the opportunity: make waste visible at the moment it happens, without asking anything of the person throwing it away.

Counting pounds of trash was never the point. Cero would only matter if it created new rituals, ones that feel as satisfying as they are sustainable. So I defined success across three areas, with the targets I’d set for a first pilot:

• Behaviour change: households send less to landfill and sort more accurately. Target: a 20% drop in landfill weight over eight weeks.
• Habit: people come back because they want to, not because they’re reminded to. Target: half of households still opening their weekly summary after the first month.
• Trust: detections and weights feel right. Target: 90% of items recognised correctly in a household trial.

The brief’s one rule shaped Cero more than anything else: the technology had to exist today, or be viable within six months. That ruled out the more futuristic ideas, like sensors that read materials chemically or a bin that sorts itself. Instead, I looked for parts that are already cheap, proven and in people’s homes:

• Cameras with on-device recognition, already in smart doorbells and phones that can name what they see.
• Load cells, the same sensors inside every kitchen and bathroom scale.

So I settled on the simplest combination that could do the job. The camera identifies. The plate quantifies. The camera sits above the bin so it sees each item as it passes through the opening, before it disappears into the pile. The plate sits beneath, weighing every drop. And instead of designing a new bin, Cero attaches to the one people already own: cheaper, faster to market, and nothing to replace.

To make the hardware feel real, I modelled both pieces myself in Blender: the camera that will sit above the bin, and the plate beneath it.

Camera identifiesPlate quantifiesTap to view in 3D

But the hardest constraint wasn’t technical. It was emotional. A product about waste can easily become a product about shame, and shame makes people look away. Every decision after this had to pass one test:

Does this make someone feel aware, not ashamed?

With all of that in mind, I narrowed Cero’s purpose down to one job:

When I throw something away, I want to understand the impact it has, without having to track it manually, so I can make more conscious decisions about my waste.

Three questions led the exploration from there:

• How do I make invisible actions feel acknowledged?
• How do I balance data and delight?
• How do I create a loop that builds on itself?

Two decisions would make or break Cero: how to capture the moment, and how to talk about it.

Capturing the moment

Within the six-month rule, there were three honest ways to capture what goes in the bin:

A. A plate that weighs. A smart plate under the bin, no camera. Cheap, simple, and no privacy questions at all. But it only knows how much, not what, so it can’t help anyone sort better or understand where their waste comes from.

B. A camera that sees. A camera on the bin recognises each item. It knows what, but not how much, so there’s no real measure of progress to come back to.

C. Both. Two off-the-shelf parts that are far more useful together than apart. The camera identifies each item and the plate weighs it, so every disposal becomes a complete moment.

Finding the voice

The same week of data can be said in very different ways. I wrote the weekly summary three times:

A. The facts. “You threw away 6.2 lb this week.” Honest, but it lands like a bill. There’s nothing to do with it except feel bad.

B. The comparison. “You wasted more than 70% of households near you.” Motivating for some, but it turns a private habit into a public ranking.

C. The progress. “6.2 lb this week, down 12% from last week.” Same number, but it points forward, and the only person you’re measured against is you.

I chose the camera and the plate, because it was the only idea that did the whole job without asking anything at the bin. And I chose progress as the voice, because it was the only one that passed the test: aware, not ashamed.

Once progress won, the same test ran through every line of copy in the app:

Underneath the copy, the four principles shaped the structure of the product:

• Clarity: waste becomes a story you can read. Weekly totals, category breakdowns and trends, never a raw list of items.
• Control: people set their own goals, and can check or recalibrate the device whenever they need to.
• Care: charts alone don’t change behaviour, so insights come as gentle suggestions, never warnings.
• Cycle: small celebrations keep the loop going. Each week builds on the last.

Together, they answered the three questions I started with: every disposal is acknowledged with its own entry, the data arrives with a little delight, and goals and badges turn each week into a loop that builds on the last.

Visually, Cero needed to feel the way it speaks: soft, present and respectful. Not loud. Not preachy. Progress is celebrated quietly, a mindful companion that offers insight, not stress.

Muted by default. Colour only for what matters: today's progress and a quiet reward.

More to ask up front. Choosing a camera and a plate meant a device to buy, a setup step and a camera in the kitchen, all things the plate alone would have avoided. In return, Cero asks nothing of people every day after. For a habit to last, that felt like the right exchange.

Slower motivation. Comparing households would likely push some people to act faster. I gave that up on purpose. Shame might work for a week, but a ritual has to feel good to last a year.

Cero stretched me in new ways. It reflects a curiosity I keep coming back to: how we might design systems that shape behaviour through feedback, not friction.

• Constraints make ideas believable. The six-month rule felt limiting at first. It’s the reason Cero feels like something you could buy, not something from a film.
• Tone is a feature. In behaviour change, how you frame the data matters as much as the data itself.
• The best design decision can be invisible. The most important choice in Cero wasn’t a screen. It was removing the need to log anything at all.

What I’d test next

As a concept, Cero’s biggest bets are still unproven. Before building further, I’d want to know:

• Does progress framing keep people engaged longer than comparison? I’d test the three weekly summaries with a handful of households over a month.
• Will families accept a camera at the bin? A simple prototype in a few real kitchens would answer that quickly.
• How accurate does recognition need to be? If people have to correct it often, effortless stops being effortless.

In the end, it’s not about the bin. It’s about the ritual.

It began as a brief about waste. It became a challenge to rethink awareness.