react-map-gl is a TypeScript React component library that wraps Mapbox GL JS and MapLibre GL JS behind a declarative, reactive API. It does not render maps itself; instead it owns the lifecycle of native map instances and exposes components (Map, Marker, Popup, Source, Layer), controls such as NavigationControl and GeolocateControl, and hooks (useMap, useControl, MapProvider) that synchronize React props with the imperative map engine. The package is structured as a monorepo: a main aggregator package re-exports two per-backend packages, @vis.gl/react-mapbox and @vis.gl/react-maplibre, plus a legacy Mapbox adapter. The current line is an alpha rewrite (v8.1.0-alpha.2) focused on performance, full typing, and 1:1 prop mapping with the native map libraries.
Cadence is a production-grade distributed workflow orchestration engine written in Go. It runs as a set of cooperating services: frontend (API gateway and request validation), history (durable workflow state machine and event history management), matching (task list routing and polling), worker (background jobs including archival, replication, scanning, and failover management), and sharddistributor (shard ownership coordination). Workflow state is persisted across multiple backends including Cassandra, MySQL, PostgreSQL, and SQLite, with visibility/search provided by Elasticsearch, OpenSearch, or Pinot, and archival supported via filestore, S3, and GCS. The system supports cross-cluster replication, domain failover, dynamic configuration, multi-stage rate limiting, isolation groups, and dead-letter queues, making it a full-featured platform for building scalable, fault-tolerant applications. Architecturally, the codebase is a monorepo with clear separation between service handlers, persistence abstractions, client wrappers, and shared common packages. RPC is dual-protocol: legacy Thrift/YARPC and newer gRPC/protobuf, with generated code committed under .gen/. Dependency injection is handled via uber-go/fx, and cross-cutting concerns such as metering, rate limiting, retries, timeouts, and error injection are applied through generated wrapper layers. The primary entry points are cmd/server/main.go for the server, cmd/tools/cli/main.go for the admin CLI, cmd/canary/main.go for health canaries, and cmd/bench/main.go for load testing. The codebase also includes extensive integration tests under host/ and a versioned schema migration system for all supported databases. Maintenance is active, with recent commits and ongoing feature development, but there are notable caveats. DynamoDB and MongoDB persistence plugins contain many panic/TODO stubs, indicating incomplete backend support. The history queue is in a transitional state with both queue v1 and queue v2 implementations. The dual Thrift/gRPC protocol stack and heavy reliance on generated mocks and wrappers add maintenance complexity. Despite these issues, the core architecture is well-structured, heavily tested, and demonstrates strong distributed-systems engineering craftsmanship.