The plumber nobody knew was missing
Plaid spent the last decade quietly wiring software into 4,600 American banks. Rory O'Reilly is doing the same thing to merchants, and almost nobody has noticed - which is exactly how he likes it. His company, Knot, builds the connective tissue that lets a person swap the card on file across Netflix, Amazon, food delivery and ride-share in a single tap, without ever typing a sixteen-digit number again.
The pitch sounds boring until you've lived the problem. You get a new card. You feel the small dread of remembering every service that has the old one saved. You give up halfway through. Cards, O'Reilly likes to point out, are the only product in your life you cannot instantly rip out and replace. You swap a phone in an afternoon. A card on file can haunt you for months.
Knot's customers are not consumers - they are card issuers, the banks and fintechs who hand you plastic and then pray you actually use it. Knot gives them a small SDK, "kind of similar to Plaid," that lets their customers re-provision a card everywhere at once. The product is invisible to most of the people it quietly helps. That invisibility is the whole point.
If we build a great product, people will come.- Rory O'Reilly on Knot's go-to-market
The numbers behind the calm are anything but. Knot now runs through roughly one of every 650 newly issued cards in the country, a sliver that O'Reilly describes with a straight face as a hockey stick that has only just started bending. Major issuers go live monthly. Mastercard implemented the API in 30 calendar days during a dogfooding study he cheerfully calls the "Dog Food Bank." A smaller challenger bank did it over a single weekend.
A CEO who wouldn't use his own card
Before Knot there was Millions, a debit card built like a slot machine. Swipe it, maybe win up to a million dollars. It became the largest challenger bank on TikTok and YouTube, fueled by a growth gimmick of giving away cash on Twitter. It also lost money, and it carried a quieter problem O'Reilly couldn't shake: customers kept complaining that updating their card everywhere was a nightmare.
The honest moment came when he caught himself. He, the CEO, was not using the Millions Card on Amazon. The friction had beaten him too. Most founders would file that under user laziness. O'Reilly read it as a market the size of every recurring payment in America. The pivot to Knot started there.
The 2-week window
A new card has roughly fourteen days to reach "top of wallet." Miss that window and the customer drifts back to their old card forever. Knot lives inside that window.
The 8% leak
Carts get abandoned about 8% of the time when a saved card fails. Issuers and merchants both bleed from it. Knot patches the leak before it opens.
Three bags of clothes, hotel to hotel
Ten years before Knot, Rory and his brother Kieran were 19 and 20, sleeping on floors and building from hotel rooms in San Francisco, keeping a website called gifs.com online as it went viral across Reddit and Imgur. The tool was almost dumb in its simplicity: it turned YouTube videos into GIFs by hitting YouTube's API. Millions of people used it. They arrived with three bags of clothes and almost nothing else.
Both had been accepted to Harvard. Both walked away two years in, after Peter Thiel handed each of them $100,000 through his fellowship for kids who quit college to build new things. Between GIFs and the debit card came a crypto detour that, by their account, moved around $80 million of Ethereum. The throughline is the brothers, not the products. Kieran is now Knot's CTO. They have been business partners through every chapter.
Ten years ago, Kieran and I were 19 and 20, sleeping on floors and building from hotel rooms.- Rory O'Reilly, reflecting on the journey
The career, in stops
- 2013gifs.com. Turns YouTube clips into GIFs. Goes viral on Reddit and Imgur. Millions of users.
- 2014The Thiel Fellowship. Both brothers leave Harvard; Thiel grants each $100,000 to build.
- 2014-2020The crypto chapter. An early Ethereum venture, reportedly moving ~$80M of ETH.
- 2020Millions. A gamified debit card; the biggest challenger bank on TikTok and YouTube.
- 2020Knot is born. Co-founded with Kieran after the card-update friction becomes obvious.
- 2023$10M Series A. Led by Nava Ventures, with Amex Ventures and Plaid.
Switching cards was just the door
Knot started with CardSwitcher, but O'Reilly talks about it as a foothold, not the building. The same connection that lets you change a card lets you do other things on a merchant's behalf: a subscription manager that cancels, pauses or adds users to a Netflix plan through the API in about 20 seconds, against competitors who lean on humans in a back office and take up to fourteen days.
He has hinted at five distinct product lines, all built on the same premise - log into the merchant, hold the connection, then act for the user. The endgame he describes openly: become the merchant-connectivity layer, with hundreds or thousands of businesses built on top of Knot, the way Plaid became the bank-connectivity layer. He projects single-digit market penetration within a year and close to 30% within four.
If it doesn't work, we won't tell a soul about it.- Rory O'Reilly on shipping only what the data justifies
Things that explain him
- He built a GIF empire before GIFs were a default internet language - riding the early Reddit and Imgur wave with a tool that simply hit YouTube's API.
- His co-founder is his brother. Kieran has been the technical half of every company Rory has ever started.
- Millions' entire growth strategy was giving away cash on Twitter and letting people win up to a million dollars on a single swipe.
- The people Knot helps mostly never learn it exists - the customer is the card issuer, and the product hides inside their app.
- His cap table reads like a fintech hall of fame: Ken Chenault, Dan Schulman, American Express, and Plaid.