Bitcoin Magazine
SecondHQ’s Bark Boasts New era of Bitcoin Payments, drawing in former Blockstream developers
SecondHQ, a new Bitcoin development lab, has gained attention recently as it drew in yet another former Blockstream employee known as “Grubles”, with over 8 years of engineering at the company. Bark, SecondHQ’s lead product, promises to deliver a next-generation “Fast, low-fee, self-custodial” wallet.
After 8+ years, today is my last day at Blockstream. It’s been an incredible opportunity to work with such a world class team on both the marketing and engineering side, and words alone do not convey my gratitude for the experience. Even though I’m leaving, I’m super excited…— grubles (@notgrubles) March 3, 2026
Alongside Grubles, other former Blockstream employees have joined the SecondHQ, such as Neil Woodfine (CMO), Steven Roose (CEO), and Erik De Smedt (CTO). The lab is currently focused on the cutting-edge of end-user Bitcoin wallet technology. In this niche of the industry, the Ark protocol is the new kid on the block, a layer two payments protocol that makes different trade-offs than the Lightning Network to deliver end users scalable self-custody and payments features at a low cost. Bark is SecondHQ’s custom implementation of the Ark protocol, designed for interoperability with the Lightning Network.
“The technique used for Bark is different from payment channels in Lightning, but the two are actually very complementary.” Grubles told Bitcoin Magazine in an exclusive interview, adding that “At Second, we’ve chosen to build an Ark that is focused entirely on making Bitcoin onboarding and payments excellent.” Their website describes an Ark-to-Lightning bridge that lets users pay Lightning invoices directly from an Ark balance with no channels, liquidity, or LSPs required. Handled atomically.
According to Grubles, the company has raised 5.1M from a private investor, with a team of 11 people working on Bark. Deep technical documentation about the project can be found at second.tech, with the main net launch expected “Soon”.
Interested users can test out making Bark payments on Signet. “I highly recommend doing so since it’s such a shift in the way we can do onboarding and payments,” said Grubles, encouraging early adopters to test out the tech.
Scaling Bitcoin Self-Custody
The most impressive claim made by Bark is the promise of self-custody at a low cost. While it is relatively trivial to scale Bitcoin payments in a custodial manner, as demonstrated by apps like Wallet of Satoshi, or as is being done now by the payments giant Cash App. Delivering self-custody for relatively small amounts of value to millions of people is another matter entirely.Onchain Bitcoin can handle roughly 7 transactions of per second, which does not scale to too many users if they are all doing maxinym self custody onchain transactions multiple times a day. To quote Knifefight’s excell
