Aleksandar Ignjatijevic

Security Researcher & Engineer

Hi! I'm a security researcher and engineer at Informal Systems, on the team building things around Quint — Informal's executable specification language — so executable specs stay at the center of how teams design, test, and verify protocols.

I still work hands-on with Go, Rust, and Solidity: auditing smart contracts, strengthening blockchain protocols, and writing formal specifications. A lot of that sits in the Cosmos and Ethereum ecosystems, where I hunt for vulnerabilities, model tricky edge cases, and think about how protocols ought to behave.

I have worked with many of our partners including Neutron, dYdX, Stride and clients such as Apex and Left Curve, and more, performing audits as well writing formal specifications and performing model-based testing on their protocols. Public audit reports I've worked on can be found under Informal Systems' GitHub organization.

When I'm not breaking things (intentionally), you'll find me building tools, learning cool new stuff, and reading. Whether it's a Rust consensus engine, a Solidity smart contract, or pushing on Quint and formal methods, I'm driven by one goal: creating secure-by-design systems that can scale across chains.

My journey into blockchain started during my Master's in High Performance Computing at the Faculty of Technical Sciences, University of Novi Sad, where I developed a blockchain-based distributed system for grading assignments. Before diving full-time into security engineering, I spent a couple of years teaching Computer Architecture and Compilers at my alma mater — mentoring students through systems programming and compiler construction.

I believe the best security comes from understanding systems inside and out — and I love sharing what I learn along the way.