@googlemaps/markerclusterer

This library does exactly what it promises - efficiently clusters large marker sets on Google Maps with minimal performance overhead. The clustering algorithm adapts well to zoom changes and handles thousands of markers without noticeable lag. Memory usage is reasonable, though you need to explicitly call clearMarkers() and setMap(null) during cleanup to avoid leaks, especially in SPAs where map instances get recreated.

The API is straightforward: pass your map and markers array, configure clustering behavior via renderer and algorithm options. Custom renderers give you full control over cluster appearance and click behavior. Error handling is minimal - invalid markers fail silently rather than throwing, which can make debugging tricky. No built-in retry logic or connection management since it's purely client-side DOM manipulation.

Configuration is flexible with sensible defaults (gridSize, maxZoom thresholds work well out of the box). Breaking changes between 1.x and 2.x required API rewrites, but 2.x has been stable. No timeout concerns since operations are synchronous. Under heavy load with 10k+ markers, initial render can block the main thread briefly - consider batching marker additions if you're dynamically loading data.

The @googlemaps/markerclusterer package does exactly what it promises with a refreshingly simple API. Getting started takes minutes - instantiate MarkerClusterer with your map and markers array, and you're done. The TypeScript support is excellent with proper type definitions that make IDE autocomplete invaluable. Common tasks like updating markers dynamically or customizing cluster appearance are straightforward once you understand the renderer pattern.

The main frustration is documentation depth. While basic examples exist, figuring out custom renderers or advanced clustering algorithms requires digging through TypeScript definitions and GitHub issues. Error messages are typically clear when you pass wrong types, but runtime issues with marker lifecycle management can be cryptic. The community is reasonably responsive on GitHub, though Stack Overflow coverage is thin.

Debugging is manageable thanks to the library's modular architecture. You can swap algorithms (GridAlgorithm, SuperClusterAlgorithm) and renderers independently, which helps isolate issues. Performance with thousands of markers is solid, though you'll want to test with your specific data patterns.

The MarkerClusterer library does exactly what it promises with minimal fuss. The basic setup is straightforward: instantiate with your map and markers array, and clustering happens automatically. TypeScript support is excellent with proper types exported for all configuration options, and IDE autocomplete works reliably for the extensive customization options.

The rendering pipeline is flexible, allowing custom renderers through the `Renderer` interface. The `SuperClusterAlgorithm` option provides better performance than the default for large datasets. However, the lifecycle management can be tricky—you need to explicitly call `clearMarkers()` before updating your marker set, or you'll end up with duplicates. The library doesn't automatically diff marker arrays, which feels unintuitive coming from modern reactive frameworks.

Error messages are generally helpful, though silent failures can occur if you pass markers that haven't been properly initialized with the map. Documentation covers the basics well with clear examples, but advanced customization scenarios (like dynamic renderer switching) require digging through TypeScript definitions.