SecondHQ, a Bitcoin development startup, continues to attract senior engineering talent from Blockstream as it builds Bark, a self-custodial Bitcoin wallet based on the Ark protocol. The company recently brought on "Grubles," an engineer with over eight years at Blockstream, joining other former Blockstream employees including CEO Steven Roose, CTO Erik De Smedt, and CMO Neil Woodfine.
Engineering Team Focuses on Ark Protocol Implementation
The 11-person team has raised $5.1 million from a private investor to develop Bark, their implementation of the Ark layer-two payment protocol. Unlike Lightning Network's payment channels, Ark uses Virtual Unspent Transaction Outputs (vUTXOs) to enable fast, low-fee payments while maintaining self-custody for users.
Bark aims to bridge the gap between Bitcoin's base layer limitations and the user experience demanded by mainstream adoption. The wallet integrates with Lightning Network, allowing users to pay Lightning invoices directly from their Ark balance without managing channels or liquidity. According to Grubles, this approach eliminates common onboarding friction points that plague existing solutions.
The technical team includes developers with experience on Core Lightning and rust-lightning library, bringing significant Lightning Network expertise to the Ark implementation. This background positions SecondHQ to execute on interoperability between the two protocols effectively.
Addressing Bitcoin Payments Scalability Challenges
Current Bitcoin scaling solutions each present trade-offs that limit adoption among non-technical users. Base-layer Bitcoin processes approximately 400,000 transactions daily—roughly one transaction per person every 55 years at global scale. Lightning Network offers improvements but requires technical knowledge for self-hosted nodes or trust compromises with mobile wallets like Phoenix, which can charge over $10 in onboarding fees.
Bark's architecture allows users to receive bitcoin and begin making Lightning payments within seconds, removing liquidity management complexity. The protocol requires users to come online at least monthly to maintain self-custody, a less stringent requirement than Lightning's always-on security model. Users retain unilateral exit capabilities, meaning they can withdraw funds to the Bitcoin base layer without operator permission.
The company has published detailed technical documentation at second.tech, with mainnet launch expected soon. A signet testnet currently allows developers and early adopters to evaluate the technology.
Implications for Bitcoin Development Careers
SecondHQ's ability to attract senior Blockstream engineers signals growing opportunity in Bitcoin layer-two development beyond Lightning Network. As Ark implementations mature, demand for developers experienced with vUTXO-based protocols, Bitcoin cryptography, and layer-two interoperability will likely increase. Professionals with Lightning Network backgrounds may find their skills transfer well to Ark development, as evidenced by SecondHQ's hiring patterns.
