About
I'm Valentyn Kit. I've spent six years getting paid to build systems that aren't allowed to be wrong.
Right now I lead the platform for a self-custody wallet that moves money for 200,000 people. The core is Rust: one reliable interface over a dozen blockchains, money movement modeled as durable state machines that survive crashes and chain reorgs, signing that never trusts a single machine. Before this it was data-intensive document pipelines, a high-concurrency game economy, and an agentic-AI platform. Different domains, same job underneath: reliability under load, the systems where "mostly works" is a failing grade.
I got good at that job by doing something quieter on nights and weekends. I rebuild the layer underneath from scratch to understand it. A small Redis in C. TCP servers across seven I/O models. A row-oriented database. A Solana indexer. Systems only stick for me once I've built the smaller, wronger version myself and watched where it breaks.
Where I'm headed is protocol engineering on Solana: consensus, validators, the runtime. I'm not there yet, and I'll say so plainly. Today I build on the chain, not the chain itself. This site is the record of closing that gap in the open, one level below and one level above, with the bugs left in.