Meet the team

Dr. Dionysis Zindros

CEO

consensus, light clients, bridges, interoperability, fast bootstrapping, algorithms, software engineering

Dionysis is a co-founder and researcher at Common Prefix focusing on consensus, light clients, bridges, interoperability, and fast bootstrapping. He did his post-doc at Stanford University, advised by David Tse. He holds a PhD from the University of Athens, advised by Aggelos Kiayias, and an Electrical and Computer Engineering degree from the National Technical University of Athens. Among other venues, he has published in IEEE S&P (Oakland), ACM CCS, ESORICS, and Financial Crypto, and presented at Black Hat Europe and Asia. Highlights of his research include the papers Non-Interactive Proofs of Proof-of-Work, Proof-of-Stake Sidechains, and Proof-of-Work Sidechains.

Nikolaos Kamarinakis

CTO

smart contract development, auditing, software engineering, offensive security

Nikolas is the CTO of Common Prefix, specializing in blockchain consensus and interoperability. He has represented Greece at the European Cyber Security Challenge, three years in a row. He holds a Bachelor's degree in Computer Science from the University of Maryland with a specialization in Cybersecurity. He has multiple years of experience in full-stack software engineering, open-source development, and offensive security. Among various projects, Nikolas led the Axelar<>XRPL integration and the end-to-end development of an EVM-to-EVM multisig-based bridge, which have processed over $200M in volume.

Prof. Zeta Avarikioti

Chief Scientist

distributed systems, scaling blockchains, cryptoeconomic incentive analysis

Zeta is an upcoming Assistant Professor at the Technical University of Vienna (TU Wien). She holds a PhD from ETH Zürich, advised by Roger Wattenhofer. She specializes in distributed systems, scalability and interoperability of blockchains, and the analysis of cryptoeconomic incentives, and she has published numerous works on light clients and bridges, including Blink, Alba, Glimpse, BitVM, Among other venues, she has published at USENIX Security, ACM CCS, NDSS, CSF, FC, AFT, AAAI, and SODA.

Haris Karavasilis

COO

business development, project management, quantitative finance, risk management

Haris works on the business side of things at Common Prefix. His background includes roles at Amazon and Piraeus Bank, where he gained valuable experience in operations, finance and risk management. He holds a Master's degree in Quantitative Finance and Risk Management from Bocconi University and an Electrical & Electronic Engineering Bachelor's degree from the University of Manchester. At Common Prefix, he contributes to both business development and project management, aiming to improve operational and financial efficiency.

Themis Papameletiou

Engineer Lead

smart contract development, testing, software engineering, algorithmic trading, rockets

Themis is a software engineer based in Athens. He has significant experience developing software for a variety of projects such as web applications, algorithmic traders, and rockets. He has worked on the Ethereum light client on Axelar and on a monitoring and alerting system for an EVM blockchain bridge. He is pursuing a Master’s degree in Electrical and Computer Engineering from the National Technical University of Athens and has also completed internships at Google and at the European Space Agency. Currently, he is focused on smart contract development and testing.

Apostolos Tzinas

Product Lead

smart contract development, algorithms, software engineering, consensus

Apostolos is a blockchain researcher and engineer at Common Prefix, specialising in blockchain consensus and decentralised finance. His research highlights include On-Chain Timestamps Are Accurate, published in Financial Cryptography 2024, and The Principal–Agent Problem in Liquid Staking, published in Financial Cryptography 2023’s 7th Workshop on Trusted Smart Contracts (WTSC). Apostolos also has extensive experience in deploying and managing both validators and full-nodes across the Ethereum and Cosmos ecosystems. In the past, as a web engineer at Maya Insights and NutriDice, he has gained extensive experience with a wide range of programming languages and technical stacks. Apostolos has a background in algorithms, having competed at national and balkan olympiads in informatics.

Dominik Apel

software engineering, auditing, offensive security

Dominik is a Software Engineer based in Vienna, Austria. He holds a Master's degree in Computer Engineering from the Technical University of Vienna (TU Wien) in Austria. He has multiple years of experience in full-stack software engineering as well as some experience in offensive security. Dominik is currently focused on smart contract development and source code auditing at Common Prefix.

Jason Athanasoglou

software engineering, interoperability, algorithms, DevOps

Jason is a software engineer based in Athens, Greece, with extensive experience in full-stack development, open-source contributions, and a strong focus on building AI-powered applications. He holds an Integrated Master’s degree in Electrical and Computer Engineering from the University of Patras. At Common Prefix, he develops blockchain and Web3 applications, focusing on decentralized and scalable solutions.

João Pedro Coelho de Azevedo

smart contract development, large scale system design, software engineering

João is a software engineer with experience in blockchain, fintech, and automotive technologies. He holds a Master’s degree in Electronics and Telecommunications Engineering from the University of Aveiro. Over the years he has contributed to multiple startups (notably Qomodo, Topos Network and Veniam), building financing risk assessment systems, smart contracts, and connected mobility solutions. His work spans backend engineering, smart contract development, and large-scale system architecture. João is a certified PMP, IEEE member, and the inventor of 13 granted patents in intelligent networking and automotive communications.

Dejan Cabrilo

software engineering, auditing, quantitative trading

Dejan is a senior software engineer with decades of C++ experience. He has worked on high-speed, high-concurrency, and high-availability trading systems at hedge funds. He has previously served as CTO and Director of Engineering in multiple companies. He holds a Computer Science degree from the Goldsmiths University of London.

Michalis Christou

smart contract development, software engineering, bridges

Michalis Christou is a Software Engineer based in Larnaca, Cyprus. He holds a Master’s degree in Advanced Computing from Imperial College London and a Bachelor’s degree in Computer Engineering from the University of Cyprus. He has multiple years of experience spanning Ethereum smart contract development, embedded systems, and more recently bridges. Michalis is currently focused on smart contract development and bridges at Common Prefix.

Jakov Mitrovski

smart contract development, auditing, software engineering, algorithms, complexity

Jakov is a software engineer and auditor based in Skopje. He holds a Master's degree in Informatics from the Technical University of Munich. Jakov specializes in the design of blockchain systems, protocol development, algorithms, and complexity, and in auditing. He has multi-year experience in software engineering, gained by working as a cloud engineer at ETAS (Bosch) GmbH and as a backend and blockchain engineer at Netcetera, Sorsix, and LOKA.

Nikola Ristić

smart contract development, full-stack web development, software engineering, algorithms, circus acrobatics

Nikola has worked as a full-stack web developer for ten years before joining Common Prefix. During his career he worked on web applications, back-end services, WebAssembly and serverless applications, and has helped many startups grow. At Common Prefix, Nikola is working on Bitcoin-related projects, smart contracts for Ethereum, CosmWasm and Solana, and cross-chain bridging. He worked on various bridges including the Bitcoin Ordinals to EVM bridge, Filecoin IPC subnets on Bitcoin, and lead the integration of Hedera to Axelar's Amplifier bridging infrastructure.

Nikos Sfakianakis

software engineering, consensus, offensive security

Nikos is a software engineer based in Athens. He is currently wrapping up his Master’s Degree in Electrical and Computer Engineering at the National Technical University of Athens where he is completing his thesis on Consensus Algorithms. He has previously worked at Mysten Labs as a Blockchain Engineer and completed an internship at the Cybersecurity Department of OTE Group. He has also competed in several Ethical Hacking and Offensive Security competitions.

Nikos Vlastaras

software engineering, distributed systems

Nikos is a software engineer based in Athens with a degree from the National Technical University of Athens. Before joining Common Prefix he worked at Panther Labs, where he contributed to production software and large-scale engineering projects. At Common Prefix he applies his experience in distributed systems to help build robust and scalable infrastructure.

Dr. Orestis Alpos

consensus, distributed systems, threshold cryptography, applied cryptography

Orestis is a blockchain researcher based in Bern, Switzerland. He holds a PhD from the University of Bern, advised by Christian Cachin, and a Computer Engineering MSc degree from the National Technical University of Athens. He specializes in distributed systems and applied cryptography. His publications include protocols for asynchronous PoS consensus, front-running prevention, consensus and cryptography with flexible trust assumptions, as well as results on composing distributed systems.

Dr. Lukas Aumayr

distributed systems, scaling blockchains, blockchain interoperability, applied cryptography, protocol analysis

Lukas is a blockchain researcher specializing in distributed systems, applied cryptography, and protocol analysis, with a focus on blockchain scalability and interoperability. Among others, his work includes advancements in Payment/Virtual Channel Network protocols, bridges, light clients, crypto-economic incentives, and BitVM. Notably, he has co-authored several papers on light clients and bridges, including Blink: An Optimal Proof of Proof-of-Work, Alba: The Dawn of Scalable Bridges for Blockchains, Glimpse: On-Demand PoW Light Client with Constant-Size Storage for DeFi, BitVM2: Bridging Bitcoin to Second Layers. Lukas is a research associate at the University of Edinburgh hosted by Aggelos Kiayias. Lukas holds a PhD from the Technical University of Vienna (TU Wien), where he was advised by Matteo Maffei and Pedro Moreno-Sanchez. His work has been published in top-tier venues such as ACM CCS, USENIX Security, IEEE Security & Privacy, NDSS, FC, and Asiacrypt.

Prof. Pyrros Chaidos

zero-knowledge proofs, voting

Pyrros holds a PhD from UCL, advised by Jens Groth, the person behind modern ZK proofs. He specializes in zero-knowledge proof systems, with applications on proof-of-stake blockchains and voting in particular, with notable scientific contributions including Efficient Zero-Knowledge Proof Systems, Efficient Zero-Knowledge Arguments for Arithmetic Circuits in the Discrete Log Setting, Mithril: Stake-based Threshold Multisignatures. Additionally, he has audited multiple deployed zero-knowledge and cryptographic codebases.

Dr. James Hsin-yu Chiang

applied cryptography, privacy-enhancing technologies, blockchain protocols

James is a postdoctoral researcher at the Systems Secruity Group at ETH Zurich, advised by Srdjan Capkun. Previously, he was a cryptography postdoctoral researcher at Aarhus University, advised by Ivan Damgård. He holds a PhD from the Technical University of Denmark where he was awarded the DTU Compute Fellowship and advised by Alberto Lluch-Lafuente, Bernardo David and Massimo Bartoletti. He holds a BSc with distinction from UCLA. His research focuses on privacy-preserving techniques motivated by recent blockchain applications and includes practical advancements in post-quantum threshold ring signatures, novel notions of differential privacy for secure multi-party computation (MPC), and the first formal model of miner-extractable-value (MEV). His research has been published in ACM CCS, Financial Cryptography, AFT and recognized with the Sui Academic Research Award. Prior to academia, James designed flight hardware for Mars rovers at JPL NASA, advised technology firms on three continents at the Boston Consulting Group, co-founded the leading solar business software company (Eturnity) and contributed to multiple open-source implementations of the original Bitcoin protocol (Core/Libbitcoin).

Prof. Bernardo David

multiparty computation, consensus

Bernardo is an Associate Professor working on cryptographic protocols for multiparty computation (MPC) and blockchains at the IT-University of Copenhagen. Among his main contributions is the first provably secure protocol for proof-of-stake blockchains (Ouroboros) and the first publicly verifiable secret sharing (PVSS) with linear complexity (SCRAPE). He has also worked on privacy preserving (auditable) smart contracts and cryptocurrencies, random beacons, sharding, signatures, theshold cryptography, time-based cryptography and zero knowledge. His work has been published in top-tier venues such as Asiacrypt, Crypto, Eurocrypt, CCS and FC. Before working with Common Prefix, he has also consulted for IOG (Cardano) and Concordium.

Dr. Robin Fritsch

DeFi, game theory, graph algorithms

Robin holds a PhD from ETH Zurich, advised by Roger Wattenhofer, focusing on game theory and decentralized finance. He completed his MSc degree in Mathematics in Data Science from the Technical University of Munich. Among other venues, he has published in AFT, ACM CCS, and AAMAS. Highlights of his research include the papers The Price of Majority Support, The Economics of Automated Market Makers, and Batching trades on Automated Market Makers.

Dr. Dimitris Karakostas

cryptocurrency wallets, macroeconomics, checkpointing

Dimitris is a cryptography researcher specialized in blockchain-based distributed ledger systems. His primary focus is on protocol design and analysis, game theory, and macroeconomic aspects of cryptocurrency systems. Notably, he was a core contributor of the Edinburgh Decentralization Index (EDI), where he worked on defining and measuring the notion of decentralization in blockchain systems. Dimitris holds a PhD from the University of Edinburgh, where he was advised by Aggelos Kiayias. His work has been published in venues like ACM CCS, Financial Cryptography, ESORICS, and ACNS.

Dr. Orfeas Stefanos Thyfronitis Litos

distributed systems, scaling blockchains, interoperability, protocol analysis, cryptoeconomic incentive analysis, voting, software engineering, payment channels

Orfeas is a research associate at Imperial College London. He obtained his PhD in Cryptography and Blockchains at the University of Edinburgh in 2021, under the supervision of Aggelos Kiayias. He has worked on building and analyzing decentralized applications on blockchains, layer-2 protocols, payment channels, and voting solutions, all through formal cryptographic methods. Among others, he has formally analyzed the security of the Lightning Network and created a novel virtual payment channel construction. He is knowledgeable in software engineering and secure architecture. His interests further include formal verification, incentive analysis, and provable security.

Prof. Julian Loss

cryptography, distributed systems, consensus

Julian is a tenured Professor at the CISPA Helmholtz Center for Information Security. He earned his Ph.D. in Mathematics from Ruhr University Bochum under the supervision of Eike Kiltz and subsequently held postdoctoral positions at the University of Maryland with Jonathan Katz and at Carnegie Mellon University with Elaine Shi. His research focuses on the intersection of cryptography and distributed protocols, with particular expertise in digital signatures, payments, consensus, and randomness generation. His work has been published in top-tier conferences, including IEEE S\&P, ACM CCS, CRYPTO, PODC, FC, AsiaCCS, and TCC.

Giulia Scaffino

scaling blockchains, blockchain interoperability, cryptoeconomic incentive analysis

Giulia is a doctoral student at the Technical University of Vienna (TU Wien), where she focuses on blockchain scalability, interoperability, and light clients She has been a summer research intern at Mysten Labs (2024) and at a16z crypto (2025). Notably, in the Sunfish paper she has formalized for the first time a new type of blockchain client: the sparse client (aka. partially stateless client). Among others, she has co-authored papers on light clients and bridges, including Blink, Alba, Glimpse.

Odysseas Sofikitis

consensus, proof-of-work, machine learning

Odysseas is a blockchain researcher specializing in consensus protocols. He holds an MEng in Electrical and Computer Engineering from Aristotle University of Thessaloniki and has previously worked on designing consensus mechanisms, “consensus-less” architectures, Byzantine fault-tolerant systems, accountable protocols and blockchain interoperability protocols such as light clients. He is co-author of the paper Pod: An Optimal-Latency, Censorship-Free, and Accountable Generalized Consensus Layer.

Dr. Sravya Yandamuri

consensus, distributed systems, applied cryptography

Sravya obtained her PhD in Distributed Systems at Duke University under the guidance of Professor Kartik Nayak with a thesis on the topic of Byzantine Agreement in Asynchronous networks. Previously, she was an intern at the now-defunct VMware Research as well as a visiting researcher at the CISPA Helmholtz Center for Information Security. Her research includes topics such as State Machine Replication, Dynamic Availability, and Parallel Broadcast. Her work has been published in notable conferences including CRYPTO and PODC. Highlights of her research include the papers Efficient and Adaptively Secure Asynchronous Binary Agreement via Binding Crusader Agreement, Low-Latency Dynamically Available Total Order Broadcast, and Leader Election with Poly-logarithmic Communication Per Party.

Tor Bognaes

business development, finance, operations

Tor supports the growth of Common Prefix, working across business development, finance, marketing, and operations. His background includes work at Amazon - where he helped scale the EU last-mile logistics network - and at a growth equity investment firm. He holds MSc degrees in Industrial Economics & Technology Management from the Norwegian University of Science and Technology and in Finance from the Norwegian School of Economics.

Myrsini Koulouri

legal, operations

Myrsini is a member of the Operations team at Common Prefix, where she supports the legal and regulatory aspects of the company's operational strategy. She holds a Law degree from Aristotle University of Thessaloniki and is a member of the Athens Bar Association. Her legal expertise and analytical mindset help ensure regulatory compliance, streamline internal processes, and reinforce the legal foundations of the organization’s activities.

Semeli Spanou

operations, logistics, biotech, data analytics

Semeli is a member of the Operations team at Common Prefix, where she collaborates with a diverse range of stakeholders to drive operational efficiency and effectiveness. She holds a Master's degree in Biotechnology, from the Agricultural University of Athens, with a focus on bioinformatics and data analysis. Semeli's organisational and analytical skills contribute to enhancing operational procedures, streamline reporting, and strengthening our logistics management.