Kilian Rausch didn’t find Bitcoin — Bitcoin found him, sideways, in Shanghai, after his employer went bankrupt and left him with no plan and an unexpected afternoon free. He walked into a meetup, met some people from a Bitcoin exchange, and days later was running mining pool operations without knowing what a mining pool was.
That accidental entry turned into Boltz, a non-custodial swap infrastructure layer that most users will never hear of — which, as Kilian will tell you, is precisely the point.
- Before Boltz, before the CEO title, before the building — there was a version of Kilian who first encountered Bitcoin. Who was that person, what was going on in his life, and what was the specific moment where Bitcoin stopped being a headline and started being something he couldn’t stop thinking about?
It all started in 2015 in China, where I was deeply concerned about infotainment systems in cars in Shanghai. Completely oblivious to the fact that just a few blocks from my home sat the headquarters of BTCC, what was then the second largest Bitcoin exchange and mining pool in the world.
When my employer, a Chinese supplier for car infotainment systems, went bankrupt just months after I started, I found myself on the street and, due to lack of a better plan, walked into a Bitcoin meetup in town. I met some folks from BTCC and just days later started working in their mining pool team without knowing anything about Bitcoin or how it functioned. A literal plunge into the unknown. 
The click came a few weeks into the job. I realized that Bitcoin let me move money anywhere in the world, instantly, without wrestling with the notoriously restrictive and bureaucratic Chinese banking system. For someone living as a foreigner in China, that wasn’t an abstract idea. It was immediately useful. That was the moment it stopped being a curiosity and became something I couldn’t stop thinking about.
- Boltz is building non-custodial submarine swaps — moving value between Bitcoin’s layers without ever holding someone’s funds. In a world full of custodial shortcuts and ‘just trust us’ bridges, why did you bet your energy on the harder, more principled path, and what do you think happens to the people who didn’t?
I’ll be honest: the decision to build non-custodial wasn’t purely Bitcoin ethics. It was also deeply selfish. Non-custodial services occupy a fundamentally different regulatory category. In the EU, the U.S. and most major jurisdictions, if you never control or hold user funds, you’re not a custodian, and the crushing compliance burden of KYC and AML requirements that applies to exchanges and custodial services simply isn’t applicable.
We understood that early and built accordingly. That said, the two motivations aren’t in conflict. The reason non-custodial services get that regulatory treatment is precisely because they’re genuinely safer for users — there’s no honeypot, no single point of failure. And development in the regulatory sphere has proven that this was the right decision.
As for the services that didn’t make that choice, frankly most swap services online are, knowingly or not, operating in a deeply gray zone they haven’t fully reckoned with yet. Holding user funds, even briefly, even technically, puts you in a different legal category.
Regulators are slow to understand this from the surface of these services… until they aren’t. Building a fully non-custodial architecture, going the hard path, was the only bet that made sense long-term.
- Your X bio says CEO — but also prompt engineer and customer support intern. That self-description is disarmingly honest and quietly says everything about how you lead. What does staying close to the user actually teach you that a dashboard, a metrics report, or a team meeting never could?
One of our strong suits is providing the best possible privacy to our users, meaning we don’t request or collect data we don’t crucially need to execute a swap. Boltz does not require accounts, sign-ups, emails or phone number. Not even an IP address (you can use our service via TOR). This also means we don’t use any telemetry at all. That’s great for privacy, but also makes it much harder to detect user pain points.
For us, these almost exclusively surface in conversations with our users, mostly via customer support tickets. Handling customer support myself helps me detect friction early, prioritize things and now with the help of AI even directly work on fixes myself. Everything gets properly reviewed and shaped by our real engineers, of course. But the distance between “user is frustrated” and “problem is solved” has collapsed in a way that wouldn’t have been possible a few months ago.
We’re a team of five (myself and four engineers), so wearing multiple hats is normal. I involve everyone in conversations with users if it’s about someone’s expertise. Everyone helps with support. Everyone stays close to the product.
- Lightning is simultaneously the most exciting and most technically unforgiving layer to build on — liquidity management, channel failures, routing complexity, user experience that can punish you in seconds. What has building Boltz taught you about Lightning that you couldn’t have learned any other way?
Fun one. Let me start with the fact that we run one of the oldest and largest Lightning nodes on the network – seven years and counting. We’ve been through enough liquidity crises and technical fires that I’ll proudly claim we’re best-in-class when it comes to node management and Lightning operations. A few things we couldn’t have learned any other way:
- We’re not a lightning payment routing business. And that changes everything. We optimize our nodes to serve our swap business, not to maximize routing profit. That makes us operate very differently from most other players on the network, and honestly, it took time to fully internalize that distinction.
- Volume creates gravity. A Lightning business with real transaction flow attracts liquidity and channel opens organically. The network starts working for you once you’ve earned it with volume.
- Be ruthless about liquidity management. Idle liquidity has real opportunity costs, and we run a liquidity-intense operation that demands high automation and constant fine-tuning like knowing when to close which channels is crucial.
- Bet on the Lightning node implementation’s community. We learned the hard way that using smaller node implementations that might be superior in some technical aspects sounds appealing until something breaks at 2am on a Sunday morning. Nobody ran into the issue because you are the largest player running that implementation. Dev support and a thriving operator community matter far more than diversification for its own sake.
You need at least two nodes to support any serious business.
- How is AI actually changing the way you build, ship, and support a Bitcoin infrastructure product, and where do you think the intersection of AI and Bitcoin is genuinely underrated right now?
Besides CEOs now shipping code (for the good and the bad…), the efficiency shift goes deeper than that. Tasks that used to take weeks now take a day or two. The unglamorous stuff that used to create drag like being stuck in “git hell”, dreading a messy rebase – it ust isn’t a thing anymore. That’s not a real quality-of-life improvement for all developers.
More recently we started using local AI models to help monitor our stack, and that’s where it starts feeling genuinely magical. Instead of hoping you checked the right Grafana dashboard in time, or that you set up an alert correctly nine months ago, you have something that actually understands your infrastructure is watching it for you. For a five-person team running critical payment infrastructure, that’s an asymmetric advantage for operations.
Everyone talks about AI agents transacting in Bitcoin, which is interesting, but the more immediate opportunity is AI making it possible for tiny, lean teams to run infrastructure at a level of reliability and professionality that previously required much larger headcounts. That’s in my opinion the quietly transformative part for Bitcoin.
- If Boltz works exactly as you dream it — non-custodial, seamless, invisible infrastructure humming beneath millions of transactions — most users will never even know it exists. Does that anonymity of success bother you, or is a world where Boltz is invisible because it just works the most beautiful outcome you can imagine?
Honestly? The idea of Boltz never surfacing is the dream. We’re already moving in that direction, Boltz is increasingly an SDK and API that other services integrate, a silent layer beneath wallets, swap aggregators, and platforms that own the end-user relationship.
I can imagine a future where we have no direct end user relationship at all, and I find that genuinely exciting rather than unsettling. There’s a particular kind of satisfaction in building infrastructure. The best plumbing is the plumbing nobody thinks about. Being invited to the main stage of a prestigious Bitcoin conference is not something we are after. All we care about is adoption. Boltz being used to execute a transaction across Bitcoin’s layers that previously was cumbersome or impossible.
Website: https://boltz.exchange/
