Markets Outlook – Why Brazil’s CBDC Won’t Launch on a Blockchain

Podcast: Markets Outlook by CoinDesk
Date: September 26, 2025
Host: Jen Senassi
Guest: Ronaldo Lemos (Founder, Institute for Technology and Society of Rio; Board Member, Stellar Development Foundation), interviewed at Stellar Meridian 2025 in Rio de Janeiro

Episode Overview

This episode explores the development of Brazil’s Central Bank Digital Currency (CBDC), known as "Drex," focusing on why its launch won’t happen on a blockchain, at least initially. CoinDesk’s Jen Senassi sits down with Ronaldo Lemos, a prominent advisor to Brazil’s central bank and a recognized voice in tech-law-policy, to unpack Drex’s progress, privacy debates, technical architecture, and the broader implications for both Brazilian citizens and the global financial landscape.

Key Discussion Points & Insights

The Innovations Driving Brazil's Financial Future

Pix and Drex — Two Pillars of Transformation

• Pix: Described as an "instant payment system" that’s free for end users and now the backbone of digital payments in Brazil.
• Drex: The upcoming digital real, designed to be "programmable" and integrated with smart contracts and platforms like Soroban.
  • Goal: Democratize finance, enabling things like easier access to high-yield Brazilian treasury bills and creating collateralized applications via smart contracts.

Quote:

“The pillars of this innovation are Pix... But the second pillar is actually Drex, which is the real digital, the digital version of the Brazilian currency. [...] The important thing about Drex is that it's programmable.”
— Ronaldo Lemos (00:54)

CBDCs vs. Stablecoins: What's the Difference and Does It Matter to Users?

• CBDCs: Public money; liability of the central bank (e.g., Drex).
• Stablecoins: Private project; liability on the issuing project.
• User Perspective: Most users care less about the underlying technology ("pipelines") and more about practical applications.

Memorable Statistic:

• “Every day there are 2.3 transactions of Pix by person in Brazil and we have like 210 million people.” (02:20)
  Illustrates phenomenal adoption and hints at high expectations for Drex.

Quote:

“The user... doesn't know the nitty gritty of how Drex works and how it operates, but it cares a lot about the applications.”
— Ronaldo Lemos (02:20)

Privacy: The Central Challenge

• A central reason Drex has been delayed; launch now expected in 2026.
• Balancing Act:
  • Aim is to mimic cash — enabling private transactions while acknowledging that some transparency is necessary for public spending.
• Technical Approaches: Exploring homomorphic encryption to enable privacy within the digital currency architecture.
• Hybrid Measures: Both legal and technical (architecture-level) protections are considered essential.

Quote:

"So there are people that are afraid that if you use a governmental issued type of money, the government will be able to see everything that we do. And we don't want that actually. We want the real to work just like a physical bill."
— Ronaldo Lemos (04:37)

Why Drex Isn’t Launching on Blockchain (Yet)

• Pilot Project: The central bank’s Drex pilot will use a “simpler architecture” that’s not blockchain-based.
• Ultimate Vision:
  • Lemos emphasizes that blockchain's borderless, transparent nature should be the long-term goal for Drex.
  • The pilot is a pragmatic step; blockchain integration remains the aspiration for scalability, interoperability, and universality.

Quote:

"The ultimate goal is to make it to the blockchain, because otherwise it's kind of pointless... Blockchains are universal blockchains across border infrastructure. So they must be the ultimate goal."
— Ronaldo Lemos (06:38)

Interoperability & the Global Promise of Digital Money

• Fragmented Foreign Exchange: Brazil's closed economy makes seamless foreign transactions challenging; stablecoins help address this.
• Interoperability Dream: Envisioning quick conversion between digital currencies (real, dollar, euro, yen).
• Open Finance as the Third Pillar:
  • In addition to Pix and Drex, open access to financial data can drive down interest rates and empower fintech-driven solutions, especially with AI integration.

Quote:

"That's why I think like the three pillars are Pix, which I think is doing great when we have Drex and then we have a third component which is open finance, which is actually access to financial data so that you can provide lower interest and you can create like a more intelligent even now with artificial intelligence solutions."
— Ronaldo Lemos (07:59)

Memorable Quotes & Their Context

• On Drex's Delay Due to Privacy:

  "Because of privacy, Drex has been held back, the schedule has been delayed, so now it's 2026 and maybe even a simpler architecture, less ambitious in the beginning."
  — Ronaldo Lemos (04:37)

• On the Importance of Blockchain as a Goal:

  "As a pilot, I think that is okay. But as the ultimate goal, as the blueprint to, you know, pay homage to Stellar, I think that is not sufficient."
  — Ronaldo Lemos (06:38)

• On Stablecoins Filling Gaps in Brazil:

  “Stablecoins, for instance, are great, because they allow Brazilians to basically have more control of how they do foreign transactions. And it's been adopted by banks and fintechs and so on, but we can figure that out in a different way.”
  — Ronaldo Lemos (07:59)

Timestamps for Key Segments

• 00:54: Lemos explains the big picture of Drex and its goal of programmability.
• 02:20: CBDC vs. Stablecoin differences and what matters to users; Pix metrics.
• 04:37: Detailed dive into the privacy challenges delaying Drex.
• 06:38: Discussion on moving away from blockchain for now, ultimate blockchain ambition.
• 07:59: The vital importance of interoperability, open finance, and stablecoins in Brazil's landscape.

Closing Note

By the episode’s close, Ronaldo Lemos underscores that Drex is a work-in-progress with big ambition: to create a private-yet-programmable digital currency for all Brazilians, with eyes set firmly on eventual blockchain integration and seamless interoperability with the global digital economy.

Host’s Closing Words:
"Ronaldo, thank you so much for joining us here at the desk and wrapping the show with us. It was a pleasure." (09:14)