--- canonical: https://tanveerriaz.me/blog/grub-build-day format: text/markdown --- From idea to demo / 15 October 2026 / 5 min read # Grub: two hours, four builders, 600 people Four teammates, about two hours, and a chance to showcase what we built in front of Anthropic. A day at Grab I will remember. I got a chance to showcase what we had built in front of Anthropic, with 600 people in the room. A couple of hours earlier, Grub was still just an idea. That was my highlight from the Claude Community Opus 5.5 Build Day at Grab in Singapore on 13 October. Four of us came together, thought about an everyday problem, planned a solution, built it, and then demoed it. All in about two hours. Built Grub at Grab. The name still makes me smile. 🐻 ## Four people and about two hours I built Grub with Ravi Sharma, Rudrappa Tumbaraguddi (RBT) and Priyadharshan Kannan. Our starting point was familiar: you sit down at a restaurant, scan a QR code, and start scrolling through the whole menu again. You already know some of what you want. Perhaps something vegetarian, something spicy, or something you enjoyed last time. But each new menu starts the conversation from zero. We thought about a dining companion that could sit between the diner and the restaurant’s menu. You could ask what to eat, get suggestions from the actual dishes, and build an order through a conversation. We called it Grub. With a demo coming up, we had to make decisions quickly. What is the idea? What can we build in the time? What will we actually show? We thought about it, planned it, executed, and then demoed. ## Then I got to show it Getting up to showcase our work in front of Anthropic and a room of 600 people was an amazing experience. I really enjoyed sharing something we had just brought to life together. There is something special about that moment. You have been discussing an idea around a table, working through choices with your teammates, and suddenly you have something you can put in front of people. Ravi, Rudrappa and Priyadharshan, thank you for being such lovely teammates. I had a great time building with you. ## What Grub does The idea is simple: scan, talk, order. A restaurant provides its menu, and the diner can ask questions, explore dishes and build a basket. Preferences can be saved for another visit, so you do not have to explain yourself every time. The shared project now includes menu onboarding from a website or menu photos, text ordering, a basket, preference memory, and a kitchen dashboard. An order is saved after the diner reviews and confirms it, with prices checked against the server’s menu. Today’s payment flow ends at “pay at the counter”. We have shared the [project code on GitHub](https://github.com/tanveerriaz/sg-opus-dev-day) and a [presentation of the Grub story](https://grub-presentation.vercel.app/). You can also [open the public restaurant prototype](https://sg-opus-dev-day.vercel.app/r/kopi-satay-house?mode=table&t=12). This is still a hackathon prototype, with more work ahead. Realtime voice is implemented in the code, but physical-phone testing remains. Installable PWA support, live payments, GrabPay handback and ordering on an external restaurant website are still roadmap ideas. The deployed app can differ from the latest shared code. Allergen and dietary questions still need confirmation with restaurant staff. ## From an idea to something you can show Opus 5.5 was amazing to build with. What stayed with me was the speed: how much easier it has become to move from conceptualisation to implementation, and then to showing something working. And the pace is not slowing down. Other models are improving so quickly too. You still need an idea, and you still have to think through what you want to build. But the distance between that thought and a demo is getting much shorter. A small side thought from the day: my brain seems to work at maximum speed for ideas when there is pressure. Give a team a short deadline and a demo to deliver, and the thinking gets very focused! A big thank you to Max Del Vita for hosting, and to Grab and Anthropic for bringing the community together. To Daniel Quek and everyone I met and shared ideas with, thank you for the conversations. We came in with an idea. We left with Grub, a demo, and a lot more ideas to build. Curious mind. Builder mode! 🇸🇬 [Explore Grub and the project evidence →](/projects#grub) [Find the Grub build-day stop in Exploring World →](/new)