Welcome José Aguinaga

At Dfns, we spend a lot of time thinking about what it actually takes to run digital asset infrastructure in production. Not in theory, not in isolated environments, but inside regulated institutions, with real users, real risk, and real accountability. That’s why we’re excited to welcome José Aguinaga as our new Head of Solutions Engineering.

José is not just an engineer, and not just a leader. He is someone who has built custody systems from first principles, deployed them under regulatory supervision, and operated them at scale. His experience sits exactly at the intersection our clients care about: cryptography, infrastructure, and compliance.

From building systems to running them under regulation

José brings more than 15 years of experience building and securing financial systems across global hubs including San Francisco, Zürich, Abu Dhabi, Dubai, Vancouver, Bali, and México City. His work spans early-stage startups, large engineering teams, and regulated financial institutions, but with a consistent focus: designing systems that are both technically sound and operationally viable.

Most recently, he co-founded Tungsten Custody, the first sovereign-backed crypto custodian in Abu Dhabi, operating under ADGM and FSRA regulation. As CTO, he led the architecture and deployment of institutional-grade custody infrastructure, covering everything from key management and signing workflows to governance models and operational procedures.

Prior to that, he headed Digital Custody Services at AMINA Bank (formerly known as SEBA Bank) in Switzerland, under FINMA supervision, where he was responsible for the safekeeping and management of billions in digital assets. This included not only building and maintaining custody systems, but also enforcing ISAE 3402 controls, coordinating audits, and ensuring compliance with AML/KYC requirements, segregation of duties, and strict chain-of-custody procedures.

This type of experience is fundamentally different from building standalone crypto systems. It means designing infrastructure that can withstand:

• external audits and regulatory scrutiny
• internal governance and approval workflows
• operational risks across teams and environments
• continuous changes in market structure and product requirements

José has operated at that level for years.

Bridging cryptography, infrastructure, and real-world deployment

Technically, José is a deeply hands-on engineer who’s worked for Plaid, Numbrs, HOPR, and Flynt Bank. His work covers cryptographic key management, MPC architectures, infrastructure security, and DevOps. He has built systems that manage keys across distributed environments, enforce policy-driven transaction controls, and integrate with broader financial infrastructure.

But what makes his profile particularly valuable is his ability to connect these components into something that actually works in production. Since 2016, through his own firm, he has advised institutions and builders on designing secure and compliant digital asset infrastructure. More recently, from Dubai, he has been supporting both regulated entities and new platforms in navigating the complexity of custody, governance, and system design in a multi-jurisdictional environment.

This is one of the layers where most projects struggle. It’s also where José has spent most of his career. He understands the trade-offs that don’t show up in whitepapers:

• how MPC systems behave under latency and operational constraints
• how governance models translate into real approval flows
• how infrastructure choices impact auditability and compliance
• how to move from a prototype to a system that can reliably handle billions in assets

Why this matters for Dfns

As Dfns continues to work with banks, fintechs, and large-scale platforms, the expectations are clear: infrastructure needs to be secure, programmable, and aligned with how financial institutions already operate. José’s role as Head of Solutions Engineering is to bridge that gap. He will work closely with our clients to design and implement:

• custody and wallet architectures tailored to regulated environments
• deployments combining MPC, HSMs, and existing internal systems
• governance models that reflect real-world approval processes and risk controls
• integration patterns that connect wallets, trading venues, and compliance systems

More broadly, he will help ensure that what we build at Dfns is not just technically correct, but deployable at scale, auditable, and aligned with institutional requirements. The industry is moving from experimentation to production. The challenge is no longer how to build crypto systems, but how to operate them reliably within the constraints of finance. That is exactly where José has been operating for years.

We’re excited to have him on board.

We’re hiring

Dfns continues to grow across engineering, product, and operations. If you’re interested in building infrastructure for the next generation of financial systems, we’d love to hear from you.

Apply here: jobs.deel.com/job-boards/dfns