Implements a generic, configurable async batch coordinator that accumulates items and flushes them when a size or delay threshold is reached. Used as the backbone for efficient storage writes (e.g., MongoDB event appends). The component is isolated (no framework-specific imports beyond basic types) and can be extracted into any project needing batched writes with backpressure handling.

Provides a distributed wait/notify mechanism for synchronous command execution across components. It uses a key-based signal store to allow one component to wait for a result emitted by another. The pattern is self-contained (depends only on Reactor and basic abstractions) and could be reused in any reactive system requiring cross-process coordination, such as saga orchestration or request-response over event streams.

Implements a fluent, type-safe DSL for constructing complex filter expressions (and/or/not, comparisons, nested paths). The builder pattern is idiomatic Kotlin and produces immutable query objects. Despite being part of the query module, the DSL itself is independent of any storage backend and could be reused in any application needing a structured filter language with JSON serialization support.