Privacy & Scaling Explorations

TL;DR

PSE was the Ethereum Foundation’s applied-cryptography R&D lab, turning research into open-source tools and infrastructure. I joined in 2023 to lead MACI and became cluster lead in 2024, responsible for: shaping org-wide strategy, reviewing technical roadmaps, mentoring team leads, and overseeing a budget above $15 million a year. My main contribution was refocusing a sprawling research portfolio on Ethereum’s privacy needs, which meant restructuring the organization and writing the 2025 privacy roadmap.

About PSE

PSE began in 2018 as Applied ZKP, an Ethereum Foundation team pushing zero-knowledge proofs from theory to practice. In 2021 it became Privacy & Scaling Explorations, widened its scope to programmable cryptography and tools across the stack, and grew into a portfolio of teams bridging academia and industry: implementing papers and building the proofs of concept, tools, and infrastructure that others could build on.

You may not know PSE by name, but you’ve probably encountered its work. A few examples:

• Scaling: some of the first proof-of-concept rollups, which inspired and accelerated much of the layer 2 ecosystem. Hubble, an optimistic rollup for payments, powered the World App beta launch. zkOPRU inspired Ernst & Young’s Nightfall. The zkEVM Community Edition brought teams together to prove Ethereum execution with zero-knowledge proofs, moving ZK-rollups from pipe dream to production.

• Private identity: Semaphore lets people prove they belong to a group without revealing who they are. It underpins privacy in World ID (over 18 million verified people as of June 2026) and in Zupass. Anon Aadhaar, for India’s national ID, and OpenPassport, now Self Protocol, wrap existing identity documents in zero-knowledge proofs, so people can prove their age or nationality without handing over the whole document.

• Web proofs: TLSNotary pioneered zkTLS, proving facts about web data without exposing the rest of it, and we helped incubate ZK Email, which does the same for signed emails. That work seeded a web-proof industry, with dozens of startups that have attracted tens of millions of dollars in venture funding.

PSE also supported hundreds of open-source grants, trusted-setup infrastructure for an ecosystem of ZK projects, and programmable cryptography education for thousands of developers around the world. Some experiments established technical feasibility; others became products and protocols.

My role

When I took over PSE in 2024, the group was roughly 100 people across a portfolio of over 30 projects, plus dozens of active grants. There was enormous technical ambition but little structure: no single mission or strategy tying it together. New initiatives were easy to start; winding them down was much harder.

Setting direction. I proposed focusing PSE on defining and delivering Ethereum’s privacy roadmap. We refocused and renamed the group from Privacy & Scaling Explorations to Privacy Stewards of Ethereum, and I wrote the 2025 roadmap around three priorities: private writes, private reads, and private proving. That gave the organization a shared purpose and specific problems to work toward.

Choosing where to invest. I pushed for problem-first planning and ecosystem impact: who was each project for, what did they need, and where could PSE make a useful contribution? That meant clearer decisions about what to lead, coordinate, monitor, or stop. I allocated budgets, redesigned the organization, and mentored team leads as we narrowed the portfolio to about 50 people and 17 projects. The hardest part was letting good people go.

I decided to leave in October 2025, handing responsibilities to new leads. Honestly, I was burnt out, but I’d gotten PSE into a good position: a clearer home within the Ethereum Foundation and a direction aligned with the EF’s vision of censorship resistance, open source, privacy, and security. The teams are carrying that forward through protocol privacy, private reads and writes at the access layer, and work with institutions.