Former Blockstream Brain Trust Joins SecondHQ to Finally Deliver Bitcoin's 'Digital Cash' Promise With New Ark Wallet

SecondHQ, a fresh Bitcoin development lab, is quietly assembling what looks like a former Blockstream all-star team. The latest recruit? An ex-Blockstream engineer known as "Grubles," who spent over 8 years at the company before jumping ship in March 2026.

Grubles isn't alone. The lab has already snagged Neil Woodfine (CMO), Steven Roose (CEO), and Erik De Smedt (CTO) — all former Blockstream talent. With 11 people total and $5.1M from a private investor, SecondHQ is betting big on their flagship product: Bark, a next-generation "fast, low-fee, self-custodial" wallet built on the Ark protocol.

"The technique used for Bark is different from payment channels in Lightning, but the two are actually very complementary," Grubles told Bitcoin Magazine. The team has built an Ark-to-Lightning bridge that lets users pay Lightning invoices directly from an Ark balance — no channels, no liquidity, no LSPs required. Everything handled atomically.

So what's the big deal? Bark claims to solve Bitcoin's long-standing scaling headache while keeping self-custody intact. That's the holy grail here. On-chain Bitcoin can handle roughly 7 transactions per second — which doesn't exactly scale to millions of daily users doing self-custodial transactions. Lightning helped, but it comes with trade-offs: running a sovereign node still requires a steep learning curve, and mobile Lightning wallets like Phoenix, while solid, still lock users into specific liquidity providers with sometimes higher fees.

Bark's approach uses Virtual Unspent Transaction Outputs (vUTXOs) — pre-signed transactions that guarantee real UTXO creation under a user's unilateral control. Unlike Lightning's always-on requirement, Ark users only need to come online once a month to refresh their vUTXOs. The tradeoff? A centralized coordination server — though users retain "unilateral exit" capabilities, meaning they can bail out to full on-chain self-custody anytime.

"With a Bark wallet, you can receive some bitcoin and begin doing Lightning payments literally in seconds. All of the liquidity micromanagement is gone," Grubles explained. "The onboarding potential is huge."

The mainnet launch is expected "soon," with testing available on Signet right now. Technical documentation lives at second.tech for the curious — and the skeptical.

Because at this point, Bitcoin needs less hype and more working products.