Notes on AI platforms and agent infrastructure, distributed systems, and reliability — by Dimuthu Wickramanayake.https://billacode.comen-gb© 2026 Dimuthu Wickramanayakehttps://billacode.com/blogs/marsclaw-building-a-personal-chat-assistant-with-bun-sqlite-and-mcphttps://billacode.com/blogs/marsclaw-building-a-personal-chat-assistant-with-bun-sqlite-and-mcpHow marsClaw was built: one Bun process gluing Telegram, Slack and WhatsApp to an agent SDK, with SQLite, an outbox, MCP tools and two runtimes.Tue, 18 Aug 2026 00:00:00 GMTDimuthu Wickramanayakeaiclaude-codenodejshttps://billacode.com/blogs/why-mcp-not-rest-apishttps://billacode.com/blogs/why-mcp-not-rest-apisREST assumes a client that read the docs at build time. An LLM isn't that client — why MCP fits agents better, and what it changes about tool design.Mon, 03 Aug 2026 00:00:00 GMTDimuthu Wickramanayakehttps://billacode.com/blogs/i-hired-a-platform-engineer-who-cant-break-anythinghttps://billacode.com/blogs/i-hired-a-platform-engineer-who-cant-break-anythingBuilding a read-only platform agent that does the on-call log and metric hunting for you, with no ability to change anything.Wed, 29 Jul 2026 00:00:00 GMTDimuthu Wickramanayakereactaidevopshttps://billacode.com/blogs/techniques-behind-a-persona-and-propensity-systemhttps://billacode.com/blogs/techniques-behind-a-persona-and-propensity-systemTurning billions of behavioural events into user personas and propensity scores: identity resolution, RFM, quantile bucketing, and leakage control.Mon, 06 Jul 2026 00:00:00 GMTDimuthu Wickramanayakehttps://billacode.com/blogs/navigating-the-2026-agent-ecosystem-langgraph-vs-openclaw-vs-google-agent-sdk-adkhttps://billacode.com/blogs/navigating-the-2026-agent-ecosystem-langgraph-vs-openclaw-vs-google-agent-sdk-adkLangGraph, OpenClaw, and Google's Agent SDK compared for 2026: what each framework assumes, and which one fits which kind of agent.Wed, 10 Jun 2026 00:00:00 GMTDimuthu Wickramanayakegcpnodejsaihttps://billacode.com/blogs/docker-desktop-vs-colima-choosing-the-right-container-runtime-for-macoshttps://billacode.com/blogs/docker-desktop-vs-colima-choosing-the-right-container-runtime-for-macosDocker Desktop's licensing pushed many macOS developers to look elsewhere. How Colima compares on performance, resources, and daily use.Sun, 07 Jun 2026 00:00:00 GMTDimuthu Wickramanayakekubernetesdockerhttps://billacode.com/blogs/my-first-2-weeks-of-using-nanoclawhttps://billacode.com/blogs/my-first-2-weeks-of-using-nanoclawTwo weeks with Nanoclaw, a lighter alternative to OpenClaw: what it does well, where it falls short, and why the smaller tool won.Sun, 10 May 2026 00:00:00 GMTDimuthu Wickramanayakeaihttps://billacode.com/blogs/go-vs-nestjs-the-backend-decision-youll-thank-yourself-for-laterhttps://billacode.com/blogs/go-vs-nestjs-the-backend-decision-youll-thank-yourself-for-laterGo or NestJS for your backend? Real numbers on memory and cold starts, honest tradeoffs, and the Cloud Function upgrade that forced the question.Sat, 25 Apr 2026 00:00:00 GMTDimuthu Wickramanayakehttps://billacode.com/blogs/saga-pattern-in-gamification-systemshttps://billacode.com/blogs/saga-pattern-in-gamification-systemsHow reactive sagas keep complex gamification workflows decoupled, resilient, and maintainable — and why the tradeoffs are worth it.Thu, 16 Apr 2026 00:00:00 GMTDimuthu Wickramanayakehttps://billacode.com/blogs/import-aware-cicd-for-firebase-cloud-functionshttps://billacode.com/blogs/import-aware-cicd-for-firebase-cloud-functionsDeploy only the Firebase Cloud Functions a change actually touches, using static import analysis instead of Bazel or Nx in your monorepo.Sat, 11 Apr 2026 00:00:00 GMTDimuthu Wickramanayakehttps://billacode.com/blogs/building-multi-tenant-microservices-on-kuberneteshttps://billacode.com/blogs/building-multi-tenant-microservices-on-kubernetesProduction-grade multi-tenant microservices on Kubernetes: namespace isolation, mTLS with Linkerd, OpenTelemetry, all running locally on kind.Sat, 28 Mar 2026 00:00:00 GMTDimuthu Wickramanayakekubernetesmicroservicesobservabilityhttps://billacode.com/blogs/living-llm-neurotransmitter-memoryhttps://billacode.com/blogs/living-llm-neurotransmitter-memoryGiving a locally-run Llama 3.1 persistent memory using a neurotransmitter-inspired model: five signals, memory tiers, and a personal knowledge graph.Thu, 19 Mar 2026 00:00:00 GMTDimuthu Wickramanayakehttps://billacode.com/blogs/traditional-software-engineering-jobs-are-finishedhttps://billacode.com/blogs/traditional-software-engineering-jobs-are-finishedA weekend project built with Claude Code without writing a line by hand — what took 12 hours instead of four days, and what the role turns into.Sat, 28 Feb 2026 00:00:00 GMTDimuthu Wickramanayakeaiclaude-codeengineeringhttps://billacode.com/blogs/handling-rpc-exceptions-in-nestjs-microserviceshttps://billacode.com/blogs/handling-rpc-exceptions-in-nestjs-microservicesExceptions don't cross RPC boundaries cleanly in NestJS. How to translate service errors into RpcException and map them back to HTTP at the gateway.Wed, 22 Oct 2025 00:00:00 GMTDimuthu Wickramanayakenestjsmicroservicesrpchttps://billacode.com/blogs/nestjs-microservice-to-microservice-communication-using-rpchttps://billacode.com/blogs/nestjs-microservice-to-microservice-communication-using-rpcWiring NestJS services together with RPC instead of HTTP: choosing a transport, defining message patterns, and calling one service from another.Fri, 17 Oct 2025 00:00:00 GMTDimuthu Wickramanayakenestjsmicroservicesrpchttps://billacode.com/blogs/my-recycling-app-did-3-pivots-and-0-recycles-a-post-mortemhttps://billacode.com/blogs/my-recycling-app-did-3-pivots-and-0-recycles-a-post-mortemA post-mortem on zylobin: three pivots, a growing feature list, zero users, and the recycling app that never recycled anything.Sat, 11 Oct 2025 00:00:00 GMTDimuthu Wickramanayakepost-mortemside-projectsproducthttps://billacode.com/blogs/this-is-fine-how-disabling-caching-can-set-your-database-ablazehttps://billacode.com/blogs/this-is-fine-how-disabling-caching-can-set-your-database-ablazeDisabling the cache made the bug disappear and the database catch fire. A short cautionary tale about what a cache is actually load-bearing for.Sat, 11 Oct 2025 00:00:00 GMTDimuthu Wickramanayakecachingdatabasesincidentshttps://billacode.com/blogs/your-laptops-ai-superpower-is-kinda-dumb-compared-to-real-apishttps://billacode.com/blogs/your-laptops-ai-superpower-is-kinda-dumb-compared-to-real-apisRunning Llama 3 locally feels like magic until you benchmark it against a commercial API. What quantization actually costs you in quality and speed.Fri, 10 Oct 2025 00:00:00 GMTDimuthu Wickramanayakellmailocal-modelshttps://billacode.com/blogs/i-built-a-website-because-sri-lankan-banks-wont-credit-card-deals-aggregatorhttps://billacode.com/blogs/i-built-a-website-because-sri-lankan-banks-wont-credit-card-deals-aggregatorScraping 50 Sri Lankan bank sites with Python, Playwright, and a local LLM to build a credit card promotions aggregator — and what broke along the way.Tue, 07 Oct 2025 00:00:00 GMTDimuthu Wickramanayakepythonscrapingside-projectshttps://billacode.com/blogs/firebase-dynamic-links-deprecated-implement-one-in-househttps://billacode.com/blogs/firebase-dynamic-links-deprecated-implement-one-in-houseFirebase Dynamic Links is shutting down. Building a replacement means handling deep links, deferred installs, social previews, and analytics.Tue, 10 Jun 2025 00:00:00 GMTDimuthu Wickramanayakefirebasemobilearchitecturehttps://billacode.com/blogs/creating-a-vod-application-like-netflix-amazon-prime-using-aws-media-converter-shttps://billacode.com/blogs/creating-a-vod-application-like-netflix-amazon-prime-using-aws-media-converter-sHow to build a Netflix-style video-on-demand pipeline on AWS using S3 for storage, MediaConvert for transcoding, and CloudFront for delivery.Sun, 23 Feb 2025 00:00:00 GMTDimuthu Wickramanayakeawsvideoarchitecturehttps://billacode.com/blogs/estimating-bigquery-result-row-count-without-running-the-whole-queryhttps://billacode.com/blogs/estimating-bigquery-result-row-count-without-running-the-whole-queryBigQuery bills by bytes scanned, so COUNT(*) on a huge table is expensive. Here's how to estimate the row count from a sampled query instead.Mon, 27 Jan 2025 00:00:00 GMTDimuthu Wickramanayakebigquerysqldatahttps://billacode.com/blogs/designing-a-video-on-demand-system-like-netflix-amazon-prime-etchttps://billacode.com/blogs/designing-a-video-on-demand-system-like-netflix-amazon-prime-etcThe components behind a Netflix-style VOD platform: ingestion, transcoding, storage, CDN delivery, DRM, and the metadata store.Thu, 02 Jan 2025 00:00:00 GMTDimuthu Wickramanayakeawsvideohttps://billacode.com/blogs/http-access-management-in-kubernetes-exposing-path-internally-and-externally-in-the-same-servicehttps://billacode.com/blogs/http-access-management-in-kubernetes-exposing-path-internally-and-externally-in-the-same-serviceExposing some paths of a Kubernetes service publicly while keeping others internal, without splitting it into two separate services.Thu, 02 Jan 2025 00:00:00 GMTDimuthu Wickramanayakekuberneteshttps://billacode.com/blogs/building-a-system-performance-monitor-in-c-with-real-time-progress-barshttps://billacode.com/blogs/building-a-system-performance-monitor-in-c-with-real-time-progress-barsWriting a system performance monitor in C using Linux headers, with real-time progress bars for CPU, memory, and disk usage.Wed, 11 Sep 2024 00:00:00 GMTDimuthu Wickramanayakerealtimehttps://billacode.com/blogs/basic-guide-to-use-nestjshttps://billacode.com/blogs/basic-guide-to-use-nestjsA starting guide to NestJS: how its TypeScript-first modules, controllers, and providers make Node.js backends easier to grow.Tue, 06 Aug 2024 00:00:00 GMTDimuthu Wickramanayakenestjsnodejshttps://billacode.com/blogs/migrating-around-50tb-from-frameio-to-aws-s3https://billacode.com/blogs/migrating-around-50tb-from-frameio-to-aws-s3Scaling a single-file transfer script into a 50TB migration from FrameIO to AWS S3: concurrency, retries, and verifying the result.Mon, 05 Aug 2024 00:00:00 GMTDimuthu Wickramanayakeawsnodejshttps://billacode.com/blogs/content-recommendation-using-elastic-search-collaborative-filtering-cfhttps://billacode.com/blogs/content-recommendation-using-elastic-search-collaborative-filtering-cfBuilding a collaborative filtering recommendation system on Elasticsearch, following an earlier content-based TF-IDF approach.Wed, 24 Jul 2024 00:00:00 GMTDimuthu Wickramanayakeawsnodejsaihttps://billacode.com/blogs/frameio-to-s3-migrating-a-100gb-file-using-axios-in-nodejshttps://billacode.com/blogs/frameio-to-s3-migrating-a-100gb-file-using-axios-in-nodejsStreaming a 100GB file from FrameIO to AWS S3 with Axios in Node.js, without loading it into memory or hitting a timeout.Wed, 24 Jul 2024 00:00:00 GMTDimuthu Wickramanayakeawsnodejshttps://billacode.com/blogs/content-recommendation-using-elastic-search-content-similarity-recommendationhttps://billacode.com/blogs/content-recommendation-using-elastic-search-content-similarity-recommendationBuilding a content-based recommendation system with Elasticsearch and TF-IDF, and what a recommendation engine really has to do.Sun, 21 Jul 2024 00:00:00 GMTDimuthu Wickramanayakevideoaidatabaseshttps://billacode.com/blogs/creating-a-react-web-app-to-upload-files-to-s3-ultra-fasthttps://billacode.com/blogs/creating-a-react-web-app-to-upload-files-to-s3-ultra-fastTwo S3 features that make browser uploads dramatically faster, wired into a React app instead of proxying files through your server.Sun, 21 Jul 2024 00:00:00 GMTDimuthu Wickramanayakeawsreacthttps://billacode.com/blogs/staying-in-the-game-as-a-software-engineerhttps://billacode.com/blogs/staying-in-the-game-as-a-software-engineerA more personal piece on staying employable and staying interested as a software engineer, rather than a technical tutorial.Mon, 27 May 2024 00:00:00 GMTDimuthu Wickramanayakeawsreacthttps://billacode.com/blogs/building-a-real-time-chat-application-with-node-js-express-and-socket-iohttps://billacode.com/blogs/building-a-real-time-chat-application-with-node-js-express-and-socket-ioA minimal real-time chat built with Node.js, Express, and Socket.IO, as groundwork before tackling a properly scalable design.Thu, 16 May 2024 00:00:00 GMTDimuthu Wickramanayakenodejsrealtimehttps://billacode.com/blogs/nextjs-basics-to-starthttps://billacode.com/blogs/nextjs-basics-to-startGetting started with Next.js coming from plain React: routing, rendering modes, and what the framework does for you by default.Wed, 08 May 2024 00:00:00 GMTDimuthu Wickramanayakereacthttps://billacode.com/blogs/creating-a-live-streaming-application-using-node-media-server-and-ffmpeg-obs-as-the-streamerhttps://billacode.com/blogs/creating-a-live-streaming-application-using-node-media-server-and-ffmpeg-obs-as-the-streamerBuilding a live streaming pipeline with Node Media Server and FFMPEG, using OBS as the streamer, after an earlier VOD encoder series.Wed, 01 May 2024 00:00:00 GMTDimuthu Wickramanayakenodejsvideorealtimehttps://billacode.com/blogs/wastego-use-machine-learning-to-identify-the-image-uploaded-to-s3-python-flask-neuralhttps://billacode.com/blogs/wastego-use-machine-learning-to-identify-the-image-uploaded-to-s3-python-flask-neuralReplacing a third-party detection API with a custom neural network served from Python and Flask for the WasteGO app.Fri, 22 Mar 2024 00:00:00 GMTDimuthu Wickramanayakeawsflutterreacthttps://billacode.com/blogs/wastego-flutter-app-to-take-a-photo-and-upload-to-aws-s3-via-go-and-gin-api-waste-share-apphttps://billacode.com/blogs/wastego-flutter-app-to-take-a-photo-and-upload-to-aws-s3-via-go-and-gin-api-waste-share-appCapturing a photo in a Flutter app and uploading it to AWS S3 through a Go and Gin backend for the WasteGO project.Tue, 19 Mar 2024 00:00:00 GMTDimuthu Wickramanayakeawsfluttergohttps://billacode.com/blogs/wastego-object-detection-using-eden-ai-to-identify-the-image-uploaded-to-s3-waste-share-apphttps://billacode.com/blogs/wastego-object-detection-using-eden-ai-to-identify-the-image-uploaded-to-s3-waste-share-appCalling Eden AI from a Go and Gin backend to identify what kind of waste appears in a photo uploaded to S3 by the Flutter app.Tue, 19 Mar 2024 00:00:00 GMTDimuthu Wickramanayakeawsfluttergohttps://billacode.com/blogs/wastego-flutter-app-to-create-a-waste-item-waste-share-apphttps://billacode.com/blogs/wastego-flutter-app-to-create-a-waste-item-waste-share-appAdding a create-item form to the WasteGO Flutter app so users can post a new waste item through the Go and Gin backend.Fri, 15 Mar 2024 00:00:00 GMTDimuthu Wickramanayakefluttergohttps://billacode.com/blogs/wastego-connecting-go-gin-with-postgres-waste-share-apphttps://billacode.com/blogs/wastego-connecting-go-gin-with-postgres-waste-share-appPart two of the WasteGO series: connecting a Go and Gin REST API to a PostgreSQL database for the waste-sharing app.Thu, 14 Mar 2024 00:00:00 GMTDimuthu Wickramanayakegodatabaseshttps://billacode.com/blogs/wastego-flutter-app-connecting-to-backend-apihttps://billacode.com/blogs/wastego-flutter-app-connecting-to-backend-apiBuilding a Flutter app that lists waste items from the Go and Gin backend API created earlier in the WasteGO series.Thu, 14 Mar 2024 00:00:00 GMTDimuthu Wickramanayakefluttergohttps://billacode.com/blogs/wastego-creating-a-go-api-with-gin-waste-share-apphttps://billacode.com/blogs/wastego-creating-a-go-api-with-gin-waste-share-appBuilding a REST API in Go with the Gin framework for WasteGO, a waste-sharing app, with scaling in mind from the start.Wed, 13 Mar 2024 00:00:00 GMTDimuthu Wickramanayakefluttergohttps://billacode.com/blogs/drm-with-bento4-ffmpeg-and-buydrmhttps://billacode.com/blogs/drm-with-bento4-ffmpeg-and-buydrmAdding DRM to a video encoding pipeline with Bento4, FFMPEG, and BuyDRM, continuing an earlier streaming encoder series.Wed, 24 Jan 2024 00:00:00 GMTDimuthu Wickramanayakenodejsvideohttps://billacode.com/blogs/e-commerce-backend-micro-service-express-typescript-and-kubernetes-part-1https://billacode.com/blogs/e-commerce-backend-micro-service-express-typescript-and-kubernetes-part-1Part one of an e-commerce microservice backend: a single Express and TypeScript service, containerised and running on Kubernetes.Thu, 11 Jan 2024 00:00:00 GMTDimuthu Wickramanayakekubernetesnodejsdockerhttps://billacode.com/blogs/e-commerce-backend-micro-service-express-typescript-and-mongodb-part-2-creating-thehttps://billacode.com/blogs/e-commerce-backend-micro-service-express-typescript-and-mongodb-part-2-creating-thePart two of the e-commerce microservice series: a working product service backed by MongoDB in Express and TypeScript.Thu, 11 Jan 2024 00:00:00 GMTDimuthu Wickramanayakenodejsdatabaseshttps://billacode.com/blogs/e-commerce-backend-microservice-with-express-typescript-and-rabbitmqhttps://billacode.com/blogs/e-commerce-backend-microservice-with-express-typescript-and-rabbitmqAdding RabbitMQ to an Express and TypeScript e-commerce backend so services talk asynchronously instead of calling each other directly.Thu, 11 Jan 2024 00:00:00 GMTDimuthu Wickramanayakekubernetesnodejsmicroserviceshttps://billacode.com/blogs/uploading-large-files-from-react-front-end-to-google-cloud-bucket-using-cloud-functions-nodejshttps://billacode.com/blogs/uploading-large-files-from-react-front-end-to-google-cloud-bucket-using-cloud-functions-nodejsUploading large files from a React front end straight into a Google Cloud Storage bucket using signed URLs and Cloud Functions.Tue, 02 Jan 2024 00:00:00 GMTDimuthu Wickramanayakegcpreactnodejshttps://billacode.com/blogs/problems-with-google-transcoder-apihttps://billacode.com/blogs/problems-with-google-transcoder-apiA significant limitation hit while using Google's Transcoder API in production, and the workarounds available once you are committed.Wed, 27 Dec 2023 00:00:00 GMTDimuthu Wickramanayakenodejsvideodevopshttps://billacode.com/blogs/fundamentals-of-backend-engineeringhttps://billacode.com/blogs/fundamentals-of-backend-engineeringHTTP fundamentals every backend engineer should know: the request and response cycle, methods, status codes, headers, and connections.Tue, 17 Oct 2023 00:00:00 GMTDimuthu Wickramanayakedevopshttps://billacode.com/blogs/selecting-a-database-for-video-metadata-storagehttps://billacode.com/blogs/selecting-a-database-for-video-metadata-storageChoosing a database for video metadata on a streaming platform: the access patterns that matter and how the candidates compare.Thu, 21 Sep 2023 00:00:00 GMTDimuthu Wickramanayakevideodatabaseshttps://billacode.com/blogs/writing-a-video-encoder-using-node-js-ffmpeg-and-bento4https://billacode.com/blogs/writing-a-video-encoder-using-node-js-ffmpeg-and-bento4A more robust streaming video encoder using Node.js, FFMPEG, and Bento4, with JavaScript promises running the steps asynchronously.Tue, 12 Sep 2023 00:00:00 GMTDimuthu Wickramanayakenodejsvideohttps://billacode.com/blogs/writing-a-video-encoder-using-node-js-and-ffmpeghttps://billacode.com/blogs/writing-a-video-encoder-using-node-js-and-ffmpegWriting a video encoder with FFMPEG and Node.js: how encoding actually works, and what the key FFMPEG options are doing.Thu, 17 Aug 2023 00:00:00 GMTDimuthu Wickramanayakenodejsvideohttps://billacode.com/blogs/building-a-subtitle-creator-with-reacthttps://billacode.com/blogs/building-a-subtitle-creator-with-reactBuilding a subtitle creator in React so you can generate and format subtitle files for video without doing the timing by hand.Sat, 24 Jun 2023 00:00:00 GMTDimuthu Wickramanayakereactnodejsvideohttps://billacode.com/blogs/scalable-e-commerce-ws-using-graphql-for-cart-service-using-netflix-dgshttps://billacode.com/blogs/scalable-e-commerce-ws-using-graphql-for-cart-service-using-netflix-dgsBuilding a GraphQL cart service with Netflix DGS inside a Spring Boot e-commerce backend, alongside the existing REST services.Wed, 12 Apr 2023 00:00:00 GMTDimuthu Wickramanayakespring-bootmicroserviceshttps://billacode.com/blogs/scalable-e-commerce-ws-joining-product-service-and-order-service-using-apache-kafkahttps://billacode.com/blogs/scalable-e-commerce-ws-joining-product-service-and-order-service-using-apache-kafkaUsing Apache Kafka to connect decoupled product and order services in a Spring Boot e-commerce backend without direct calls.Sat, 08 Apr 2023 00:00:00 GMTDimuthu Wickramanayakespring-bootmicroservicesdatabaseshttps://billacode.com/blogs/creating-a-scalable-backend-for-an-e-commerce-application-using-spring-boot-spring-cloud-andhttps://billacode.com/blogs/creating-a-scalable-backend-for-an-e-commerce-application-using-spring-boot-spring-cloud-andStarting a scalable e-commerce backend with Spring Boot, Spring Cloud, and Eureka service discovery, after experimenting with Kafka.Fri, 07 Apr 2023 00:00:00 GMTDimuthu Wickramanayakekubernetesspring-bootmicroserviceshttps://billacode.com/blogs/scalable-e-commerce-ws-handling-requests-using-spring-cloud-gatewayhttps://billacode.com/blogs/scalable-e-commerce-ws-handling-requests-using-spring-cloud-gatewayAdding Spring Cloud Gateway in front of an e-commerce microservice backend to route and filter every incoming request.Fri, 07 Apr 2023 00:00:00 GMTDimuthu Wickramanayakespring-bootnodejsmicroserviceshttps://billacode.com/blogs/scalable-e-commerce-ws-product-service-implementation-using-postgresql-and-hibernatehttps://billacode.com/blogs/scalable-e-commerce-ws-product-service-implementation-using-postgresql-and-hibernateImplementing the product service of a Spring Boot e-commerce backend with PostgreSQL and Hibernate handling persistence.Fri, 07 Apr 2023 00:00:00 GMTDimuthu Wickramanayakespring-bootreactmicroserviceshttps://billacode.com/blogs/spring-boot-series-scaling-the-stock-market-data-service-with-apache-kafkahttps://billacode.com/blogs/spring-boot-series-scaling-the-stock-market-data-service-with-apache-kafkaRevisiting a Spring Boot stock market service two years on, and scaling it with Apache Kafka to handle far more symbols.Mon, 03 Apr 2023 00:00:00 GMTDimuthu Wickramanayakespring-bootmicroserviceshttps://billacode.com/blogs/deploying-a-simple-node-server-free-of-charge-using-render-and-connect-it-to-a-free-database-inhttps://billacode.com/blogs/deploying-a-simple-node-server-free-of-charge-using-render-and-connect-it-to-a-free-database-inDeploying a Node server and connecting it to a managed database without paying anything, using Render's free tier end to end.Mon, 27 Mar 2023 00:00:00 GMTDimuthu Wickramanayakeawsreactnodejshttps://billacode.com/blogs/chaos-faced-while-deploying-lambda-with-aws-samhttps://billacode.com/blogs/chaos-faced-while-deploying-lambda-with-aws-samThe deployment problems that hit while shipping a charity web app on AWS SAM, Lambda, and DynamoDB, and how each one was resolved.Sat, 25 Mar 2023 00:00:00 GMTDimuthu Wickramanayakeawsnodejsdevopshttps://billacode.com/blogs/creating-a-weather-app-from-vanilla-js-and-phphttps://billacode.com/blogs/creating-a-weather-app-from-vanilla-js-and-phpBuilding a weather app with plain JavaScript and a PHP backend, with no framework involved: the fetch call, the API, and the markup.Tue, 17 Jan 2023 00:00:00 GMTDimuthu Wickramanayakephpdatabaseshttps://billacode.com/blogs/charity-web-app-backend-firebase-creating-the-express-app-with-firestore-databasehttps://billacode.com/blogs/charity-web-app-backend-firebase-creating-the-express-app-with-firestore-databaseCreating an Express app inside Firebase Cloud Functions and wiring it to Firestore for the charity web app backend.Fri, 13 Jan 2023 00:00:00 GMTDimuthu Wickramanayakegcpnodejsdatabaseshttps://billacode.com/blogs/charity-web-app-backend-using-firebase-api-and-cloud-storehttps://billacode.com/blogs/charity-web-app-backend-using-firebase-api-and-cloud-storeRebuilding a charity web app backend on Firebase, using Cloud Functions, Firestore, and Cloud Storage in place of the AWS stack.Wed, 11 Jan 2023 00:00:00 GMTDimuthu Wickramanayakeawsgcpdatabaseshttps://billacode.com/blogs/aws-lambda-typescript-charity-web-app-handling-s3-file-upload-event-from-lambda-functionhttps://billacode.com/blogs/aws-lambda-typescript-charity-web-app-handling-s3-file-upload-event-from-lambda-functionTriggering a TypeScript Lambda from an S3 upload event, and wiring it into the charity web app's document handling flow.Wed, 26 Oct 2022 00:00:00 GMTDimuthu Wickramanayakeawsreactnodejshttps://billacode.com/blogs/react-with-typescript-series-charity-web-app-uploading-files-to-aws-s3https://billacode.com/blogs/react-with-typescript-series-charity-web-app-uploading-files-to-aws-s3Uploading files to AWS S3 directly from a React front end, skipping the round trip through your own backend server.Mon, 24 Oct 2022 00:00:00 GMTDimuthu Wickramanayakeawsreactnodejshttps://billacode.com/blogs/aws-lambda-typescript-charity-web-app-student-service-connected-to-dynamodbhttps://billacode.com/blogs/aws-lambda-typescript-charity-web-app-student-service-connected-to-dynamodbReplacing hardcoded stubs with real DynamoDB persistence in the TypeScript Lambda student service behind the charity web app.Sat, 22 Oct 2022 00:00:00 GMTDimuthu Wickramanayakeawsnodejsmicroserviceshttps://billacode.com/blogs/aws-lambda-typescript-charity-web-app-student-service-with-event-driven-server-less-computinghttps://billacode.com/blogs/aws-lambda-typescript-charity-web-app-student-service-with-event-driven-server-less-computingBuilding the Student service as a TypeScript Lambda with full CRUD operations, after a Hello World start on serverless Node.js.Sat, 22 Oct 2022 00:00:00 GMTDimuthu Wickramanayakeawsnodejsmicroserviceshttps://billacode.com/blogs/aws-lambda-charity-web-app-introhttps://billacode.com/blogs/aws-lambda-charity-web-app-introStarting a serverless backend for a scholarship charity, and why Lambda and DynamoDB beat an always-on server when the budget is zero.Fri, 21 Oct 2022 00:00:00 GMTDimuthu Wickramanayakeawsvideohttps://billacode.com/blogs/aws-lambda-typescript-charity-web-app-start-using-event-driven-server-less-computinghttps://billacode.com/blogs/aws-lambda-typescript-charity-web-app-start-using-event-driven-server-less-computingMoving a charity web app backend to event-driven serverless: the first TypeScript Lambda, project layout, and local development.Fri, 21 Oct 2022 00:00:00 GMTDimuthu Wickramanayakeawsnodejsdockerhttps://billacode.com/blogs/react-with-typescript-series-charity-web-app-deploying-to-github-pageshttps://billacode.com/blogs/react-with-typescript-series-charity-web-app-deploying-to-github-pagesDeploying the React and TypeScript charity web app to GitHub Pages for free, before wiring up any backend integration.Thu, 20 Oct 2022 00:00:00 GMTDimuthu Wickramanayakereactnodejsdevopshttps://billacode.com/blogs/react-with-typescript-series-charity-web-app-form-state-managementhttps://billacode.com/blogs/react-with-typescript-series-charity-web-app-form-state-managementFixing the state management problems in a dynamic React form that was built with higher-order components in the previous tutorial.Wed, 19 Oct 2022 00:00:00 GMTDimuthu Wickramanayakereactnodejshttps://billacode.com/blogs/react-with-typescript-series-charity-web-app-higher-order-componentshttps://billacode.com/blogs/react-with-typescript-series-charity-web-app-higher-order-componentsUsing the higher-order component pattern in React and TypeScript to build a dynamic form for the charity web app.Sun, 21 Aug 2022 00:00:00 GMTDimuthu Wickramanayakereactnodejshttps://billacode.com/blogs/react-with-typescript-series-charity-web-app-components-developmenthttps://billacode.com/blogs/react-with-typescript-series-charity-web-app-components-developmentBuilding the React and TypeScript components for the charity web app from the wireframes designed in the previous tutorial.Sat, 13 Aug 2022 00:00:00 GMTDimuthu Wickramanayakereactnodejsdevopshttps://billacode.com/blogs/aws-lambda-serverless-kotlin-waste-share-app-series-creating-the-user-api-dynamodb-setuphttps://billacode.com/blogs/aws-lambda-serverless-kotlin-waste-share-app-series-creating-the-user-api-dynamodb-setupBuilding a full user API with AWS Lambda, the Serverless Framework, and Kotlin, backed by a DynamoDB table for the waste-share app.Sun, 10 Jul 2022 00:00:00 GMTDimuthu Wickramanayakeawskotlinmicroserviceshttps://billacode.com/blogs/react-basic-series-charity-web-app-planning-the-uihttps://billacode.com/blogs/react-basic-series-charity-web-app-planning-the-uiTurning the charity web app's requirements into wireframes and a component plan before writing any more React code.Wed, 04 May 2022 00:00:00 GMTDimuthu Wickramanayakereactnodejshttps://billacode.com/blogs/react-basic-series-charity-web-app-creating-a-react-app-with-typescripthttps://billacode.com/blogs/react-basic-series-charity-web-app-creating-a-react-app-with-typescriptStarting a React and TypeScript app for a charity that processes student financial aid applications: project setup and structure.Thu, 28 Apr 2022 00:00:00 GMTDimuthu Wickramanayakereactnodejsdatabaseshttps://billacode.com/blogs/aws-certified-solution-architect-aurorahttps://billacode.com/blogs/aws-certified-solution-architect-auroraAmazon Aurora for the AWS Solution Architect exam: how it differs from standard RDS, read replicas, failover, and when the cost is justified.Thu, 21 Apr 2022 00:00:00 GMTDimuthu Wickramanayakeawsdatabasesdevopshttps://billacode.com/blogs/aws-certified-solution-architect-elasticachehttps://billacode.com/blogs/aws-certified-solution-architect-elasticacheElastiCache for the AWS Solution Architect exam: Redis versus Memcached, caching patterns, and taking read load off your database.Thu, 21 Apr 2022 00:00:00 GMTDimuthu Wickramanayakeawsnodejsdatabaseshttps://billacode.com/blogs/aws-certified-solution-architect-rdshttps://billacode.com/blogs/aws-certified-solution-architect-rdsAmazon RDS for the AWS Solution Architect exam: managed SQL databases, multi-AZ deployments, read replicas, and how backups behave.Thu, 21 Apr 2022 00:00:00 GMTDimuthu Wickramanayakeawsdatabaseshttps://billacode.com/blogs/aws-certified-solution-architect-asghttps://billacode.com/blogs/aws-certified-solution-architect-asgAuto Scaling Groups for the AWS Solution Architect exam: scaling policies, launch configurations, and matching capacity to network load.Wed, 20 Apr 2022 00:00:00 GMTDimuthu Wickramanayakeawsreacthttps://billacode.com/blogs/aws-certified-solution-architect-elbhttps://billacode.com/blogs/aws-certified-solution-architect-elbLoad balancers for the AWS Solution Architect exam: what scalability actually means, and how ALB, NLB, and Classic ELB differ in practice.Tue, 19 Apr 2022 00:00:00 GMTDimuthu Wickramanayakeawsdockerrealtimehttps://billacode.com/blogs/aws-certified-solution-architect-ebs-efs-and-instance-storagehttps://billacode.com/blogs/aws-certified-solution-architect-ebs-efs-and-instance-storageEBS, EFS, and instance store compared for the AWS Solution Architect exam: durability, sharing between instances, and picking the right one.Mon, 18 Apr 2022 00:00:00 GMTDimuthu Wickramanayakeawsdatabaseshttps://billacode.com/blogs/aws-certified-solution-architect-ec2-amihttps://billacode.com/blogs/aws-certified-solution-architect-ec2-amiEC2 and AMIs for the AWS Solution Architect exam: instance types, pricing models, and building reusable machine images from a running box.Mon, 18 Apr 2022 00:00:00 GMTDimuthu Wickramanayakeawsreacthttps://billacode.com/blogs/check-for-number-of-available-paths-in-an-obstaclegame-board-javascripthttps://billacode.com/blogs/check-for-number-of-available-paths-in-an-obstaclegame-board-javascriptA common coding-test problem solved in JavaScript: counting available paths across a grid board when obstacles block some cells.Fri, 25 Feb 2022 00:00:00 GMTDimuthu Wickramanayakenodejshttps://billacode.com/blogs/aws-lambda-serverless-kotlin-waste-share-app-series-introhttps://billacode.com/blogs/aws-lambda-serverless-kotlin-waste-share-app-series-introStarting a serverless backend in Kotlin: the stack behind a waste-sharing app built on AWS Lambda and the Serverless Framework.Sun, 03 Oct 2021 00:00:00 GMTDimuthu Wickramanayakeawsreactkotlinhttps://billacode.com/blogs/aws-certified-solution-architect-iamhttps://billacode.com/blogs/aws-certified-solution-architect-iamIAM for the AWS Solution Architect exam: root versus IAM users, groups, policies, roles, and the least-privilege habits that go with them.Wed, 22 Sep 2021 00:00:00 GMTDimuthu Wickramanayakeawshttps://billacode.com/blogs/aws-certified-solution-architect-introhttps://billacode.com/blogs/aws-certified-solution-architect-introStart of a tutorial series for the AWS Certified Solution Architect exam: what AWS is, how regions work, and what the exam expects of you.Wed, 22 Sep 2021 00:00:00 GMTDimuthu Wickramanayakeawshttps://billacode.com/blogs/flutter-series-connecting-the-spring-boot-web-socket-market-data-real-time-market-datahttps://billacode.com/blogs/flutter-series-connecting-the-spring-boot-web-socket-market-data-real-time-market-dataConnecting a Flutter app to a Spring Boot WebSocket so stock market prices update in real time rather than on a manual refresh.Fri, 11 Jun 2021 00:00:00 GMTDimuthu Wickramanayakespring-bootflutterreacthttps://billacode.com/blogs/spring-boot-series-creating-a-web-socket-to-send-real-time-market-datahttps://billacode.com/blogs/spring-boot-series-creating-a-web-socket-to-send-real-time-market-dataAdding a WebSocket to a Spring Boot service so stock market data streams to clients in real time instead of being polled.Thu, 10 Jun 2021 00:00:00 GMTDimuthu Wickramanayakespring-bootrealtimehttps://billacode.com/blogs/flutter-series-connecting-ui-to-spring-boot-backendhttps://billacode.com/blogs/flutter-series-connecting-ui-to-spring-boot-backendWiring the Flutter stock market UI to its Spring Boot backend endpoint, completing the first working version of the app.Mon, 07 Jun 2021 00:00:00 GMTDimuthu Wickramanayakespring-bootflutterrealtimehttps://billacode.com/blogs/flutter-series-implementing-stock-market-watch-list-uihttps://billacode.com/blogs/flutter-series-implementing-stock-market-watch-list-uiBuilding a stock market watch list UI in Flutter, ready to connect to the Spring Boot backend from earlier in the series.Mon, 07 Jun 2021 00:00:00 GMTDimuthu Wickramanayakespring-bootfluttervideohttps://billacode.com/blogs/flutter-series-creating-the-first-flutter-applicationhttps://billacode.com/blogs/flutter-series-creating-the-first-flutter-applicationCreating your first Flutter app to display stock market data from the Spring Boot service built earlier in this series.Sun, 06 Jun 2021 00:00:00 GMTDimuthu Wickramanayakespring-bootflutterhttps://billacode.com/blogs/spring-boot-series-sending-stock-market-data-in-json-formhttps://billacode.com/blogs/spring-boot-series-sending-stock-market-data-in-json-formImproving a Spring Boot stock service to return data for a whole set of symbols as JSON, instead of one stock at a time.Sun, 06 Jun 2021 00:00:00 GMTDimuthu Wickramanayakespring-boothttps://billacode.com/blogs/spring-boot-series-unit-testing-basicshttps://billacode.com/blogs/spring-boot-series-unit-testing-basicsUnit testing basics for a Spring Boot app that pulls stock prices from the Yahoo Finance API: what to mock and what to assert.Sun, 06 Jun 2021 00:00:00 GMTDimuthu Wickramanayakespring-boothttps://billacode.com/blogs/spring-boot-series-stock-market-data-end-pointhttps://billacode.com/blogs/spring-boot-series-stock-market-data-end-pointImproving the Spring Boot stock market endpoint before deploying to production, with cleaner structure and error handling.Fri, 04 Jun 2021 00:00:00 GMTDimuthu Wickramanayakespring-bootdevopshttps://billacode.com/blogs/create-the-first-spring-boot-apphttps://billacode.com/blogs/create-the-first-spring-boot-appSkipping the theory and building your first Spring Boot application: initialising the project, its structure, and running it locally.Wed, 02 Jun 2021 00:00:00 GMTDimuthu Wickramanayakespring-boot