Visualization used in the SwissTable explanation

Inside Google’s Swiss Table: A High-Performance Hash Table Explained

Swiss Tables: A Modern, High-Performance Hash Table Swiss Table is a high-performance hash table design introduced by Google engineers in 2017. It has since inspired many standard-library implementations across languages, including: Go 1.24 ships its map with this design (up to 60% faster) Rust’s standard HashMap has also moved from Robin Hood hashing to a Swiss Table-inspired layout. Datadog reported as much as 70% memory savings after migrating to Swiss Table Open Addressing, Briefly Open addressing is one way to implement a hash table. Unlike separate chaining, which uses external data structures such as linked lists or trees, open addressing implements the entire hash table as a single contiguous array. ...

December 10, 2025 · 3 min · Donghyung Ko
Benchmark chart showing SIMD-accelerated JSON parsing performance

SIMD JSON: Unlocking Maximum Performance for JSON Deserialization

Limitations of Traditional Scalar State Machine Parsers The JSON parsing algorithms we commonly use are based on scalar state machine parsers. Scalar parsers read the input string byte by byte, parsing it through state transitions within the state machine. For example: When encountering a quotation mark ("), it indicates the start of a string. When encountering a colon (:), it indicates that a value is expected next. Here is a simplified version of a scalar parser in pseudocode: ...

September 22, 2025 · 7 min · Donghyung Ko