Engineering articles on Java, Spring Boot, microservices, cloud-native delivery, and legacy enterprise modernization.https://viruchith.com/en-ushttps://viruchith.com/articles/build-an-on-demand-wireguard-vpn-on-aws/https://viruchith.com/articles/build-an-on-demand-wireguard-vpn-on-aws/Spin up a private WireGuard VPN on AWS in minutes for about a cent an hour. Covers instance sizing, static vs ephemeral IPs, hardening, cost alerts and Terraform.Sat, 07 Nov 2026 00:00:00 GMTDevOpsWireguardAWSVPNTerraformOpenTofuEC2SecurityNetworkinghttps://viruchith.com/articles/the-longest-password-in-the-world-exploiting-sshhole-on-alpine-musl/https://viruchith.com/articles/the-longest-password-in-the-world-exploiting-sshhole-on-alpine-musl/How passwords over 256 characters bypass OpenSSH authentication on Alpine Linux (musl libc), and how to secure containerized environments.Thu, 05 Nov 2026 00:00:00 GMTSecurityAlpineOpenSSHCVELinuxSecurityContainermuslsshhttps://viruchith.com/articles/recycled-mobile-number-problems-india/https://viruchith.com/articles/recycled-mobile-number-problems-india/Bought a new Jio or Airtel SIM and can't log in to Flipkart, Swiggy, or Instagram? How recycled mobile numbers cause OTP, account, and spam problems, and how to protect yourself.Wed, 04 Nov 2026 00:00:00 GMTSecurityMobileIndiaSIMOTPConsumer-Tipshttps://viruchith.com/articles/beneath-the-waves-before-the-light-how-copper-connected-the-world/https://viruchith.com/articles/beneath-the-waves-before-the-light-how-copper-connected-the-world/How did humanity connect continents before the internet? A look at the history, failures, and engineering of undersea copper cables.Wed, 07 Oct 2026 00:00:00 GMTHistoryUndersea CablesTelegraphHistoryEngineeringTAT-14 CableTransatlantic Telegraph Cableshttps://viruchith.com/articles/zero-trust-llm-architecture-defending-conversational-agents-from-injection-confused-deputies-and-context-degradation/https://viruchith.com/articles/zero-trust-llm-architecture-defending-conversational-agents-from-injection-confused-deputies-and-context-degradation/Secure Enterprise LLM Agents with Spring Boot: Prevent prompt injection, stop BOLA/Confused Deputy attacks via OAuth 2.1 OBO, and manage context windows with chat compaction.Sun, 04 Oct 2026 00:00:00 GMTLLM ArchitectureLLM SecuritySpring BootPrompt InjectionConfused DeputyContext WindowOAuth 2.1 OBOJevLLAMA GuardMCPChat Compactionhttps://viruchith.com/articles/building-an-offline-fault-tolerant-bus-announcement-system-for-bengaluru-a-software-engineers-commute-notes/https://viruchith.com/articles/building-an-offline-fault-tolerant-bus-announcement-system-for-bengaluru-a-software-engineers-commute-notes/How to architect an offline, low-cost Passenger Information System (PIS) for dense urban transit. Solves GPS multipath jitter, opposing-lane ambiguities, and flyover false positives using route state machines and vector geofencing.Sat, 12 Sep 2026 00:00:00 GMTSystem DesignPassenger Information SystemGPSGeofencingOffline-firstFault ToleranceLow-costHardwareSoftwareFirmwareBengaluruhttps://viruchith.com/articles/under-the-hood-how-google-aws-and-github-evaluate-permissions-in-under-5ms/https://viruchith.com/articles/under-the-hood-how-google-aws-and-github-evaluate-permissions-in-under-5ms/Explore how hyperscale systems like Google Workspace, AWS, and GitHub process complex RBAC, IAM, and nested group permissions at blazing speeds.Fri, 04 Sep 2026 00:00:00 GMTSystem DesignSystem DesignIAMAuthorizationRBACReBAChttps://viruchith.com/articles/cracking-the-firewall-how-stun-servers-and-hole-punching-power-real-world-p2p-networks/https://viruchith.com/articles/cracking-the-firewall-how-stun-servers-and-hole-punching-power-real-world-p2p-networks/Learn how peer-to-peer (P2P) systems like BitTorrent, WebRTC, and decentralized apps bypass NAT firewalls using STUN servers and UDP/TCP hole punching.Sun, 23 Aug 2026 00:00:00 GMTNetworkingP2PDiscoverySTUNHole PunchingNAT TraversalWebRTCBitTorrenthttps://viruchith.com/articles/parallel-ai-coding-agents-how-to-run-an-army-of-llms-without-git-chaos/https://viruchith.com/articles/parallel-ai-coding-agents-how-to-run-an-army-of-llms-without-git-chaos/Discover the engineering patterns behind parallel AI coding agents. Learn how tools like Cursor, Copilot, and Claude Code isolate workspaces, avoid deadlocks, and merge code cleanly.Fri, 17 Jul 2026 00:00:00 GMTAI Coding Agentsmulti agent systemsparallel LLMsautonomous codingsoftware engineeringhttps://viruchith.com/articles/under-the-hood-of-datadog-and-grafana-how-to-ingest-millions-of-metrics-without-crashing/https://viruchith.com/articles/under-the-hood-of-datadog-and-grafana-how-to-ingest-millions-of-metrics-without-crashing/Discover how hyper-scale observability platforms like Datadog and Grafana ingest 10M+ metrics per second without crashing. Learn the secrets of TSDB architecture, lock-free ring buffers, and Gorilla compression.Mon, 13 Jul 2026 00:00:00 GMTSystem DesignSystem DesignTelemetry PipelineHyperscale IngestionDatadogGrafanaGorilla compressionTime Series DatabasesLMAX Disruptorhttps://viruchith.com/articles/the-hype-loop-confronting-conformity-bias-in-software-architecture/https://viruchith.com/articles/the-hype-loop-confronting-conformity-bias-in-software-architecture/Discover how conformity bias shapes computer science, from historical microservice bloat to the modern rush of embedding LLMs into every feature—and how to build from first principles.Thu, 25 Jun 2026 00:00:00 GMTSoftware ArchitectureConformity BiasMicroservicesLLMFirst Principleshttps://viruchith.com/articles/supercharge-your-ai-workflow-introducing-prompt-butler/https://viruchith.com/articles/supercharge-your-ai-workflow-introducing-prompt-butler/Discover Prompt Butler, a lightweight, free, and open-source (FOSS) JavaFX desktop overlay that supercharges your AI workflow. Learn how to eliminate context-switching friction by instantly searching, filling variables, and copying your favorite LLM prompt templates straight to your system clipboard using a global hotkey.Thu, 18 Jun 2026 00:00:00 GMTProductivityAILLMPrompt EngineeringProductivityJavaFXOpen Sourcehttps://viruchith.com/articles/mastering-concurrency-in-java-from-a-simple-air-fryer-to-a-scalable-multi-elevator-system/https://viruchith.com/articles/mastering-concurrency-in-java-from-a-simple-air-fryer-to-a-scalable-multi-elevator-system/Master Java concurrency from scratch! Learn how to manage thread-safe state updates using AtomicInteger, wait/notify, and LinkedBlockingQueue through hands-on Air Fryer and Multi-Elevator system simulations. Prevent data races and scale your multi-threaded apps efficiently.Tue, 16 Jun 2026 00:00:00 GMTJava ConcurrencyJavaConcurrencyMulti-threadingThread SafetyAtomicIntegerhttps://viruchith.com/articles/eliminating-microservice-blind-spots-introducing-project-vega-an-open-source-graphrag-architecture-engine/https://viruchith.com/articles/eliminating-microservice-blind-spots-introducing-project-vega-an-open-source-graphrag-architecture-engine/Tired of microservice documentation going instantly obsolete? Discover the proposal for Project VEGA, a secure, zero-trust GraphRAG discovery engine built on SvelteKit.Thu, 11 Jun 2026 00:00:00 GMTLLMProject VEGAGraphRAGMicroservicesCorporate Knowledge Managementhttps://viruchith.com/articles/the-superchip-shift-how-nvidia-rtx-spark-is-re-engineering-the-modern-laptop/https://viruchith.com/articles/the-superchip-shift-how-nvidia-rtx-spark-is-re-engineering-the-modern-laptop/Discover how the new NVIDIA RTX Spark superchip matches up against Apple Silicon. Explore its groundbreaking unified memory architecture, AI performance tiers, and the flagship Windows laptops powered by this next-gen ARM processor.Mon, 01 Jun 2026 00:00:00 GMTHardwareNVIDIARTX SparkARMLaptopshttps://viruchith.com/articles/demystifying-git-how-your-local-machine-tracks-code-without-a-database/https://viruchith.com/articles/demystifying-git-how-your-local-machine-tracks-code-without-a-database/Ever wonder how Git tracks changes without an SQLite database? Discover Git's hidden architecture, from content-addressable storage to snapshot optimization.Thu, 28 May 2026 00:00:00 GMTSoftware DevelopmentGitVersion ControlSoftware ArchitectureSystem Designhttps://viruchith.com/articles/building-compliance-grade-secure-audit-trails-in-modern-spring-applications/https://viruchith.com/articles/building-compliance-grade-secure-audit-trails-in-modern-spring-applications/Master secure, compliance-grade audit trails in Spring Boot 3.3+. Learn how to implement AOP method auditing, track entity changes, and secure logs for GDPR, HIPAA, and PCI-DSS compliance.Sun, 24 May 2026 00:00:00 GMTSecurityAudit TrailsSpring BootAOPGDPRHIPAAPCI-DSShttps://viruchith.com/articles/architecting-privacy-anonymous-indexing-in-fintech-and-kyc-infrastructure/https://viruchith.com/articles/architecting-privacy-anonymous-indexing-in-fintech-and-kyc-infrastructure/Learn how anonymous indexing (blind indexing) secures sensitive PII in FinTech and KYC pipelines. Discover the technical architecture required to run high-speed database queries over strongly encrypted data without sacrificing performance or compliance.Tue, 19 May 2026 00:00:00 GMTSecurityPrivacyFinTechKYCAnonymous IndexingConfiguration Management DatabaseDBMShttps://viruchith.com/articles/phish-slayer-an-open-source-framework-for-context-aware-social-engineering-resilience/https://viruchith.com/articles/phish-slayer-an-open-source-framework-for-context-aware-social-engineering-resilience/PHISH SLAYER is a FOSS project designed to solve the personalization gap in security awareness training. By integrating LLMs with the Model Context Protocol (MCP), it securely bridges internal CMDB data to generate hyper-realistic, context-aware phishing simulations. Build elite cyber resilience by testing your workforce against threats that reference real project IDs, asset names, and personnel hierarchies.Wed, 06 May 2026 00:00:00 GMTCybersecurityPhishingSocial EngineeringLarge Language ModelsModel Context ProtocolConfiguration Management Databasehttps://viruchith.com/articles/system-design-analysis-have-i-been-pwned-hibp/https://viruchith.com/articles/system-design-analysis-have-i-been-pwned-hibp/Unlock the genius behind HaveIBeenPwned's architecture. Discover how k-anonymity, serverless functions, and Cloudflare Workers handle billions of records for ultimate password security and efficiency.Sat, 02 May 2026 00:00:00 GMTSystem DesignSystem DesignHIBPK-AnonymityServerlessCloudflare WorkersSecurityhttps://viruchith.com/articles/the-architects-of-the-global-web-understanding-tier-1-isps-in-2026/https://viruchith.com/articles/the-architects-of-the-global-web-understanding-tier-1-isps-in-2026/The internet is often visualized as a cloud, but in reality, it is a physical, highly stratified hierarchy of hardware and agreements. At the very peak of this structure are the Tier 1 Internet Service Providers (ISPs). These entities are the true "backbone" of the global internet, owning the massive fiber-optic arteries that connect continents and dictate the flow of the world’s data.Tue, 21 Apr 2026 00:00:00 GMTNetworkingISPTier 1Internet ArchitectureBGPPeeringNetworkingLumenhttps://viruchith.com/articles/the-synchronization-engine-how-agoda-and-otas-prevent-double-bookings/https://viruchith.com/articles/the-synchronization-engine-how-agoda-and-otas-prevent-double-bookings/Ever wonder how Agoda stops double bookings when the last room is listed on Expedia too? This guide explains the complex system design and APIs. Learn about distributed locks, eventual consistency, and how OTAs coordinate to keep inventory accurate across platforms.Sun, 19 Apr 2026 00:00:00 GMTSystems DesignSystems DesignDistributed SystemsHotel BookingOTAsPMShttps://viruchith.com/articles/from-local-alarms-to-global-scale-how-reminder-systems-work/https://viruchith.com/articles/from-local-alarms-to-global-scale-how-reminder-systems-work/Explore the engineering behind reminder notification systems, from local OS hardware timers to distributed multi-tiered architectures. Learn how to scale from single-user alarms to millions of concurrent events using message queues, partitioning, and UTC synchronization.Sun, 12 Apr 2026 00:00:00 GMTSystems DesignSystems DesignDistributed SystemsReminder SystemsMessage QueuesUTChttps://viruchith.com/articles/the-physics-of-precision-mastering-time-in-a-laggy-world/https://viruchith.com/articles/the-physics-of-precision-mastering-time-in-a-laggy-world/Explore the mechanics of time synchronization in distributed systems. Learn how Network Time Protocol (NTP) and Precision Time Protocol (PTP) use Round-Trip Delay (RTD) math to combat network latency and achieve nanosecond accuracy.Wed, 08 Apr 2026 00:00:00 GMTSystems DesignSystems DesignTime SynchronizationNTPPTPhttps://viruchith.com/articles/the-bitmask-secret-how-trains-and-buses-manage-intermediate-bookings-without-chaos/https://viruchith.com/articles/the-bitmask-secret-how-trains-and-buses-manage-intermediate-bookings-without-chaos/Discover how IRCTC and redBus solve segment-based inventory challenges using Bitmasking. Learn the bitwise logic behind intermediate bookings, ACID-compliant architectures, and how virtual bucketing optimizes revenue for long-distance journeys.Tue, 03 Mar 2026 00:00:00 GMTSystems DesignSystems DesignInventory ManagementBitmaskingIRCTCredBushttps://viruchith.com/articles/the-retail-fort-how-supermarkets-handle-internet-outages/https://viruchith.com/articles/the-retail-fort-how-supermarkets-handle-internet-outages/Explore how enterprise retail systems maintain 100% uptime during connectivity failures. Learn about the 'Defensive Layers' of supermarket networks, including dual-fiber redundancy, 5G failover, and 'Store and Forward' offline payment processing.Sat, 28 Feb 2026 00:00:00 GMTResilienceRetailResilienceNetworkOffline Processinghttps://viruchith.com/articles/the-invisible-mechanics-of-drag-and-drop-backend-strategies-for-custom-ordering/https://viruchith.com/articles/the-invisible-mechanics-of-drag-and-drop-backend-strategies-for-custom-ordering/Solve the 'write cascade' problem in custom ordering. Explore backend strategies for drag-and-drop systems, comparing Integer Sequencing, Floating Point Ranking, and Lexicographical Ranking (Lexorank) for performant, O(1) database updates.Wed, 04 Feb 2026 00:00:00 GMTRankingRankingAlgorithmComputer ScienceLexo RankTODO apphttps://viruchith.com/articles/what-is-fuzzy-search-a-forgiving-approach-to-finding-data/https://viruchith.com/articles/what-is-fuzzy-search-a-forgiving-approach-to-finding-data/Stop losing users to simple typos. Learn how fuzzy search algorithms like Levenshtein Distance, N-grams, and Phonetic Matching create a more 'forgiving' search experience. Explore implementation strategies for both frontend (Fuse.js) and backend (Elasticsearch) environments.Sun, 01 Feb 2026 00:00:00 GMTSearchSearchAlgorithmFuzzy SearchComputer Sciencehttps://viruchith.com/articles/protecting-your-api-a-simple-guide-to-rate-limiting-in-spring-boot/https://viruchith.com/articles/protecting-your-api-a-simple-guide-to-rate-limiting-in-spring-boot/Secure your Spring Boot APIs from scraping and DoS attacks by implementing rate limiting. This guide walks through the Token Bucket algorithm using the Bucket4j library, providing a step-by-step implementation for reliable request throttling.Sat, 31 Jan 2026 00:00:00 GMTRate LimitingRateLimitSpringSpringBootRESTAPIhttps://viruchith.com/articles/guide-to-cdns-pops-and-jsdelivr/https://viruchith.com/articles/guide-to-cdns-pops-and-jsdelivr/aster global content delivery with this comprehensive guide to CDNs and Points of Presence (PoPs). Learn how to use jsDelivr to serve NPM packages and GitHub assets with blazing speed, auto-minification, and multi-provider reliability.Thu, 22 Jan 2026 00:00:00 GMTCDNCDNJSDelivrCachinghttps://viruchith.com/articles/turbocharging-address-autocomplete-implementing-in-memory-caching-with-cache2k-and-spring-boot/https://viruchith.com/articles/turbocharging-address-autocomplete-implementing-in-memory-caching-with-cache2k-and-spring-boot/Learn how to 'turbocharge' your address autocomplete service by implementing in-memory caching in Spring Boot. This guide explores using cache2k for sub-10ms response times, non-blocking access, and resilient performance, turning a sluggish UI into a snappy user experience.Mon, 19 Jan 2026 00:00:00 GMTCachingCacheCache2KSolrInMemoryRAMSearchhttps://viruchith.com/articles/moving-from-stateful-to-stateless-scaling-your-web-app-with-external-session-storage/https://viruchith.com/articles/moving-from-stateful-to-stateless-scaling-your-web-app-with-external-session-storage/Unlock horizontal scaling by transitioning from stateful to stateless architecture. Learn how to decouple session data using Redis, NoSQL, or SQL to improve fault tolerance, enable load balancing, and prepare your web app for auto-scaling.Sun, 18 Jan 2026 00:00:00 GMTScalabilitySessionScalabilityHttpRedisNoSQLSQLWebAppLoadBalancingAutoScalinghttps://viruchith.com/articles/take-back-control-of-your-data-a-guide-to-syncthing-for-secure-mobile-backups-and-p2p-sharing-over-laninternet/https://viruchith.com/articles/take-back-control-of-your-data-a-guide-to-syncthing-for-secure-mobile-backups-and-p2p-sharing-over-laninternet/Stop relying on centralized cloud giants. Learn how to use Syncthing for private, encrypted, and free P2P file synchronization. This guide covers setting up secure mobile backups and sharing large files over LAN or the internet without storage limits.Tue, 13 Jan 2026 00:00:00 GMTP2PP2PSyncthingFileSharingFileSynchttps://viruchith.com/articles/stop-using-mathrandom-for-security-seriously/https://viruchith.com/articles/stop-using-mathrandom-for-security-seriously/Stop compromising your Spring Boot security with Math.random(). Learn why java.util.Random is predictable and how to implement SecureRandom for cryptographically strong tokens, session IDs, and API keys.Mon, 12 Jan 2026 00:00:00 GMTJavaJavaSecureProgrammingRandomEntropySecurity