Bartosz Sypytkowski
Yrs Yjs OSS Core Team Member
Warsaw, Masovian Voivodeship, Poland
Summary
🤩
Rockstar🎓
Top SchoolBartosz Sypytkowski is a seasoned software engineer with 12 years of experience specializing in distributed systems, functional programming, and database internals. An active open-source core contributor to projects like Yrs/Yjs, Akka.NET and the Rust port of Yjs, he has deep experience making CRDT-based realtime collaboration and Distributed Data robust and production-ready. He has shipped backend and DB-engine features at Turso (libsql) and built realtime sync, novel versioning and vector-search indexing for Appflowy, improving client/server stability and observability across the stack. Comfortable across languages and environments—from Rust and F# to WebAssembly and HTTP-based DB protocols—he focuses on correctness, performance and maintainable synchronization protocols. Based in Warsaw, he combines hands-on engineering with mentoring and architecture work, often surfacing subtle concurrency and replication bugs others miss. A pragmatic OSS advocate, he prefers building reproducible tests and tooling that make complex distributed behaviors observable and reliable.
12 years of coding experience
12 years of employment as a software developer
Engineer's degree, Computer Science, Engineer's degree, Computer Science at Bialystok University of Technology
Polish, English
Stackoverflow
7,532reputation
176kreached
198answers
18questions
akka
top-5%
Github Skills (36)
algorithm10
algorithms10
sqlite10
testing10
net10
dotnet10
data-structure10
data-structures10
rust10
replication10
akka-net10
concurrency10
unit-testing9
serialization9
akka9
Programming languages (17)
Github contributions (5)
y-crdt/y-crdt
Apr 2021 - Jan 2023
Rust port of Yjs
Role in this project:
Back-end Developer
Back-end DeveloperContributions:4 releases, 156 reviews, 587 commits in 1 year 9 months
Contributions summary:Bartosz primarily focused on bug fixes and optimizations within the Rust implementation of Yjs. They addressed issues in text deletion and insert-after-delete scenarios, modifying core data structures like ItemContent and ensuring correct behavior during concurrent operations. Their contributions also involved debugging concurrent insert/delete scenarios and adding tests to validate functionality.
crdtrustyjs
akkadotnet/akka.net
Jul 2014 - Jun 2020
Canonical actor model implementation for .NET with local + distributed actors in C# and F#.
Role in this project:Back-end Developer
Back-end DeveloperContributions:4 reviews, 454 commits, 338 PRs in 6 years
Contributions summary:Bartosz primarily contributed to the Akka.NET project, focusing on the implementation of the Distributed Data collections. They were involved in designing the data structure for distributed data, the serialization of those collections, and the logic behind merging and propagating data across different nodes. The work included refactoring shard logic and fixing bugs to enhance the reliability and functionality of the system for both the distributed data and persistence variants.
dotnetconcurrencydistributed-actorsdistributed-programmingc-sharp
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.