Joran Greef
Founder & CEO at TigerBeetle
United States
Summary
🤩
Rockstar🎓
Top SchoolJoran Greef is a founder and systems engineer with 11 years of experience building high-performance, safety-critical backend systems and databases. As Creator, Founder and CEO of TigerBeetle he designed and implemented a financial transactions database focused on correctness and low-latency journaling, network protocol, and self-testing logic used in mission-critical payments. His earlier work at Coil and Ronomon blends performance engineering, security research, and low-level systems programming—contributions include io_uring support in Zig and cross-platform I/O fixes in libuv. He combines an accounting background with deep kernel- and storage-level expertise, bringing a pragmatic, security-minded approach to distributed financial software. A hands-on leader, he’s known for shipping auditable, production-ready primitives that anticipate failure modes few engineers consider.
11 years of coding experience
12 years of employment as a software developer
Bachelor of Commerce - BCom Accounting, Bachelor of Commerce - BCom Accounting at University of Cape TownGrey High School
Stackoverflow
587reputation
124kreached
12answers
0questions
Github Skills (35)
filesystem10
system-programming10
multiplatform10
windows10
io-uring10
cross-platform10
c1110
file-operations10
io10
linux-kernel10
c1710
darwin10
zig10
sql10
fileio10
Programming languages (13)
Github contributions (5)
tigerbeetle/tigerbeetle
Apr 2020 - Dec 2022
The financial transactions database designed for mission critical safety and performance.
Role in this project:
Back-end Developer
Back-end DeveloperContributions:799 reviews, 1321 commits, 65 PRs in 2 years 8 months
Contributions summary:Joran focused on building the core back-end functionality of the financial transactions database. Their contributions include implementing database queries, adding result codes for various operations, and integrating journal writing for data persistence. They established the network protocol and implemented the server-side logic to process incoming transfer requests, as well as add a client to submit these requests. The user also incorporated business logic for transfer creation and validation, along with self-testing capabilities.
database
libuv/libuv
Mar 2015 - Jun 2021
Cross-platform asynchronous I/O
Role in this project:Back-end Developer
Back-end DeveloperContributions:9 PRs, 111 comments, 14 issues in 6 years 4 months
Contributions summary:Joran primarily focused on improving the file system event handling capabilities of libuv, specifically on Windows and Darwin (macOS) platforms. Their contributions include fixing bugs related to path handling and buffer overflows in file system event processing, improving the accuracy of fsync and fdatasync on macOS. They also added cross-platform file open constants and implemented direct I/O support. These changes improve the robustness and cross-platform compatibility of the library.
asynchronousionetworkingunixwindows
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