Harry Kalogirou
Founder at Sentry Brain
Larissa, Thessaly and Central Greece
Summary
🤩
Rockstar🎓
Top SchoolHarry Kalogirou is a founder and seasoned systems-minded software engineer with 12+ years building everything from OS components and compilers to embedded flight controllers and blockchain infrastructure. He blends low-level expertise in C++/Go and compiler design—demonstrated by significant contributions to the Vyper compiler’s new Venom IR—with practical product leadership across digital health and IoT startups. Comfortable across the stack, he has led engineering teams as CTO and technical director, taught software topics academically, and still designs PCBs and power electronics for embedded projects. Based in Larissa, Greece, he is an active open-source contributor and early-stage investor who pairs deep technical craftsmanship with a knack for turning research-grade ideas into real-world products.
11 years of coding experience
17 years of employment as a software developer
MSc, Software Engineering, MSc, Software Engineering at University of IoanninaBSc, Informatics, BSc, Informatics at University of Piraeus
English, Greek
Stackoverflow
71reputation
16kreached
4answers
2questions
Github Skills (33)
algorithm10
vyper10
nav10
dataflow10
python10
optimizers10
control-flow-graph10
analyse10
c1110
intermediate-code10
c1710
compiler-design10
filter10
sys10
optimisation10
Programming languages (8)
Github contributions (5)
vyperlang/vyper
Dec 2022 - Apr 2025
Pythonic Smart Contract Language for the EVM
Role in this project:
Back-end Developer & Compiler Engineer
Back-end Developer & Compiler EngineerContributions:148 reviews, 65 PRs, 11 pushes in 2 years 3 months
Contributions summary:Harry primarily contributed to the development of the Vyper compiler, focusing on the Venom intermediate representation (IR). They implemented a new IR, Venom, for the Vyper compiler, and refactored the code to use Venom. Their work included adding new instructions, improving the API, and optimizing various passes within the compiler pipeline, such as liveness analysis, store elimination, algebraic optimization, and branching optimizations. The user's contributions improved the compiler's architecture, code generation, and optimization capabilities.
pythonsmart-contractethereumcontractblockchain
iNavFlight/inav
Apr 2020 - May 2020
INAV: Navigation-enabled flight control software
Role in this project:Embedded Systems Engineer / IoT Developer
Embedded Systems Engineer / IoT DeveloperContributions:7 commits, 1 PR, 4 comments in 22 days
Contributions summary:Harry primarily contributed to the navigation aspects of the flight control software. Their work involved implementing a configurable control smoothness factor within the navigation system, which included modifying filtering logic for both pitch and roll adjustments. They also refactored code to use common functions for cutoff frequency calculations and updated the navigation configuration version, suggesting ongoing maintenance and refinement of the control algorithms. The user's contributions are focused on improving the precision and responsiveness of the flight control system.
flightnavigationquadcopterfpvairplane
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