Advanced Development Topics

• Statsig Under the Hood: A Deep Dive into Internal Architecture and Implementation

  21 min read • Published on April 15, 2024 • Last Updated On August 6, 2025

  Statsig is a unified experimentation platform that combines feature flags, A/B testing, and product analytics into a single, cohesive system. This post explores the internal architecture, SDK integration patterns, and implementation strategies for both browser and server-side environments.TLDR• Unified Platform: Statsig integrates feature flags, experimentation, and analytics through a single data pipeline, eliminating data silos and ensuring statistical integrity• Dual SDK Architecture: Server SDKs download full config specs and evaluate locally (sub-1ms), while client SDKs receive pre-evaluated results during initialization• Deterministic Assignment: SHA-256 hashing with unique salts ensures consistent user bucketing across platforms and sessions• High-Performance Design: Global CDN distribution for configs, multi-stage event pipeline for durability, and hybrid data processing (Spark + BigQuery)• Flexible Deployment: Supports cloud-hosted, warehouse-native, and hybrid models for different compliance and data sovereignty requirements• Advanced Caching: Sophisticated caching strategies including bootstrap initialization, local storage, and edge integration patterns• Override System: Multi-layered override capabilities for development, testing, and debugging workflows

• Modern Video Playback Stack

  14 min read • Published on May 1, 2024 • Last Updated On July 18, 2025

  Learn the complete video delivery pipeline from codecs and compression to adaptive streaming protocols, DRM systems, and ultra-low latency technologies for building modern video applications.TLDRModern Video Playback is a sophisticated pipeline combining codecs, adaptive streaming protocols, DRM systems, and ultra-low latency technologies to deliver high-quality video experiences across all devices and network conditions.Core Video Stack ComponentsCodecs: H.264 (universal), H.265/HEVC (4K/HDR), AV1 (royalty-free, best compression)Audio Codecs: AAC (high-quality), Opus (low-latency, real-time)Container Formats: MPEG-TS (HLS), Fragmented MP4 (DASH), CMAF (unified)Adaptive Streaming: HLS (Apple ecosystem), MPEG-DASH (open standard)DRM Systems: Widevine (Google), FairPlay (Apple), PlayReady (Microsoft)Video Codecs ComparisonH.264 (AVC): Universal compatibility, baseline compression, licensedH.265 (HEVC): 50% better compression than H.264, 4K/HDR support, complex licensingAV1: 30% better than HEVC, royalty-free, slow encoding, growing hardware supportVP9: Google’s codec, good compression, limited hardware supportAdaptive Bitrate StreamingABR Principles: Multiple quality variants, dynamic segment selection, network-aware switchingHLS Protocol: Apple’s standard, .m3u8 manifests, MPEG-TS segments, universal compatibilityMPEG-DASH: Open standard, XML manifests, codec-agnostic, flexible representationCMAF: Unified container format for both HLS and DASH, reduces storage costsStreaming ProtocolsHLS (HTTP Live Streaming): Apple ecosystem, .m3u8 manifests, MPEG-TS/fMP4 segmentsMPEG-DASH: Open standard, XML manifests, codec-agnostic, flexibleLow-Latency HLS: 2-5 second latency, partial segments, blocking playlist reloadsWebRTC: Sub-500ms latency, UDP-based, peer-to-peer, interactive applicationsDigital Rights Management (DRM)Multi-DRM Strategy: Widevine (Chrome/Android), FairPlay (Apple), PlayReady (Windows)Encryption Process: AES-128 encryption, Content Key generation, license acquisitionCommon Encryption (CENC): Single encrypted file compatible with multiple DRM systemsLicense Workflow: Secure handshake, key exchange, content decryptionUltra-Low Latency TechnologiesLow-Latency HLS: 2-5 second latency, HTTP-based, scalable, broadcast applicationsWebRTC: <500ms latency, UDP-based, interactive, conferencing applicationsPartial Segments: Smaller chunks for faster delivery and reduced latencyPreload Hints: Server guidance for optimal content deliveryVideo Pipeline ArchitectureContent Preparation: Encoding, transcoding, segmentation, packagingStorage Strategy: Origin servers, CDN distribution, edge cachingDelivery Network: Global CDN, edge locations, intelligent routingClient Playback: Adaptive selection, buffer management, quality switchingPerformance OptimizationCompression Efficiency: Codec selection, bitrate optimization, quality ladder designNetwork Adaptation: Real-time bandwidth monitoring, quality switching, buffer managementCDN Optimization: Edge caching, intelligent routing, geographic distributionQuality of Experience: Smooth playback, minimal buffering, optimal quality selectionProduction ConsiderationsScalability: CDN distribution, origin offloading, global reachReliability: Redundancy, fault tolerance, monitoring, analyticsCost Optimization: Storage efficiency, bandwidth management, encoding strategiesCompatibility: Multi-device support, browser compatibility, DRM integrationFuture TrendsOpen Standards: Royalty-free codecs, standardized containers, interoperable protocolsUltra-Low Latency: Sub-second streaming, interactive applications, real-time communicationQuality Focus: QoE optimization, intelligent adaptation, personalized experiencesHybrid Systems: Dynamic protocol selection, adaptive architectures, intelligent routing