Product manager turns postcards into app in 4 hours

Priscilla Tina, a San Francisco product manager, used Claude Code to build Postcard Press in four hours and get it working on her phone before ProductCon—then scaled it to monetization by the end of 2025. More than 100 postcards have been sent through the app,

On the night before ProductCon in San Francisco, Priscilla Tina didn’t sleep so much as sprint. The 28-year-old product manager was trying to walk into the event with something she could show—an app prototype built from scratch and working on her phone.

She wanted it to solve a very old problem in a very new way: sending postcards without stamps. without the post office. and without the hassle of finding a mailbox. Last November, Tina sat down and built the idea with Claude Code—sending postcards while skipping the traditional delivery steps. By the time ProductCon arrived, Postcard Press had crossed from experiment to something real.

Postcard Press lets users upload pictures and type messages, then relies on Postgrid to handle printing and delivery. Tina built the bare bones of the app in four hours the night before the conference and got it working on her phone.

At the event, she shared it with other product managers. Their reaction was immediate and practical: they asked when it would be ready to go, saying they wanted to send friends postcards for Christmas. Tina also tested demand on social media, posting a video about the app that drew 20,000 views.

Once the interest was there, she decided to finish the app before the end of the year.

Over the next two months, before the end of 2025, Tina worked through monetization, payment integration, and launch. Since she launched in December, more than 100 postcards have been sent through Postcard Press. Each card costs about $2.

The math is tight. Postgrid’s services cost $0.82, and Stripe charges $0.30 per card. Tina said she isn’t making much profit per card.

That hasn’t stopped her from building more.

Her bigger motivation is not squeezing revenue out of an experiment—it’s closing the gap she feels between digital life and analog joy. Tina described a personal pivot: “A lot of people. including myself. grew up surrounded by technology. ” she said. “but I also had analog products in my life when I was growing up. and I didn’t have a phone.” In her account. the shift is stark now: “Cut to now. I’ve started living on my phone.”.

She links the daily habits of modern screen time to something less satisfying. “We’re spending a lot of time brainrotting. looking at a lot of AI slop. ” she said. adding that “spending all our time on our phones isn’t very meaningful.” When she wants connection. she points to face-to-face interaction and the value of returning to older pleasures.

Postcard Press is her attempt to bridge those worlds—using a familiar analog ritual while removing the friction that usually makes people skip it.

Tina’s motivation for the app started with her own habits. She said she’d been sending postcards with her friends for years and found it fun to stay in touch while traveling. But she also realized she had bought so many postcards that it became inconvenient to write them. Then there’s the routine she wanted to avoid: buying stamps at the post office and walking to mailboxes to send them.

To build Postcard Press, she leaned on an unusually direct workflow for a non-traditional coder. Tina said she has an engineering background, but not necessarily coding, so she needed help.

Before launch, she shared the app with friends. One friend sat down with a laptop and tried to hack the website. He found a security error that allowed him to send 10 postcards without paying Tina anything. He told her she needed to fix it before she launched it publicly. The experience pushed her to shore up the app’s security.

Payments were the other steep climb. Tina said she didn’t know how to set up a Stripe payment system or what it would cost. Her friends pushed her to move faster than she expected—one told her she could integrate Stripe to do payments and credit card payments in 30 minutes. while another bet against that timeline. Tina said she sat down and got it working in 30 minutes.

Instead of hiring a developer, she asked Claude to read through Stripe’s API documentation. She said it was able to integrate a payment step in the checkout process.

The sequence—prototype at ProductCon, user demand from conference conversations and a 20,000-view social video, then monetization completed by the end of 2025—maps to a personal rule Tina keeps returning to: build quickly, test with people, and treat problems as part of the process.

Even if Postcard Press doesn’t become a long-term commercial hit, she said the point is learning. “Building this app has been a really valuable learning lesson for me,” she said, and added that it’s brought some “fun cash on the side.”

Already, she’s turned that momentum into other analog-inspired products.

One is Mini Print, inspired by the Polaroid walls she’s noticed in friends’ homes and local businesses. Mini Print lets people turn photos into little digital Polaroids and arrange them into a custom wall on their phone to use as phone backgrounds. Tina built Mini Print with Claude Code, and she said it has reached around 2,000 users.

She said she loves seeing friends share their walls with her.

For what comes next, Tina is still chasing the feel of analog, but through digital interfaces. “So many of my favorite analog experiences are just waiting to be reimagined digitally,” she said, adding that she’s having fun incorporating nostalgic interfaces. Nature and plants are next on her list.

Postcard Press Claude Code Postgrid Stripe ProductCon San Francisco product manager analog apps Mini Print Polaroid walls payments integration