Kronotop is a distributed, Redis-protocol-compatible transactional database built on FoundationDB. It serves as a high-performance document store, key-value store, and ordered map, with support for secondary indexes (single-field, compound, vector), BQL query language, vector search (HNSW), and cluster sharding/replication. The system exposes a Redis RESP2/RESP3 wire protocol, making it directly compatible with existing Redis clients and tooling. Internally, it uses a custom log-structured volume storage engine with segments, changelog, vacuum, and primary-standby replication, while FoundationDB handles metadata, coordination, and ACID transactions. The architecture is modular: core services (Bucket, Stash, ZMap, Volume), a Netty-based network layer, and a command handler registry. The codebase demonstrates strong software engineering with advanced features like a query optimizer, adaptive scan budgeting, hybrid logical clocks, and comprehensive command metadata. It is not a data research repository; it is a production-grade database application with extensive testing and observability.