https://pubudu.dev/ Recent content on Pubudu.Dev Hugo -- gohugo.io en © 2026 Pubudu Jayawardana Sun, 22 Feb 2026 00:00:00 +0000 https://pubudu.dev/posts/understanding-lambda-tenant-isolation/ Sun, 22 Feb 2026 00:00:00 +0000 https://pubudu.dev/posts/understanding-lambda-tenant-isolation/ Lambda tenant isolation lets you share a single Lambda function across tenants while keeping their execution environments completely separate. Let’s look at why this matters and how it works. https://pubudu.dev/posts/simple-leave-mangement-with-lambda-durable-functions/ Tue, 13 Jan 2026 00:00:00 +0000 https://pubudu.dev/posts/simple-leave-mangement-with-lambda-durable-functions/ This blog post explains my experience developing a simple human-in-the-loop functionality for a leave management application using Lambda Durable Functions. https://pubudu.dev/posts/cloudwatch-multi-metric-alarms/ Mon, 20 Oct 2025 00:00:00 +0000 https://pubudu.dev/posts/cloudwatch-multi-metric-alarms/ Amazon CloudWatch now allows you to monitor multiple individual metrics via a single alarm. By dynamically including metrics to monitor via a query, this helps to manage a single alarm for monitoring dynamic resources. https://pubudu.dev/posts/detect-eventbridge-target-failure-part-2/ Tue, 30 Sep 2025 00:00:00 +0000 https://pubudu.dev/posts/detect-eventbridge-target-failure-part-2/ When EventBridge cannot deliver a message to a target, there are several ways to get notified. In this blog we discuss how EventBridge enhanced logging can be used in this scenario. https://pubudu.dev/posts/detect-eventbridge-target-failure-part-1/ Tue, 23 Sep 2025 00:00:00 +0000 https://pubudu.dev/posts/detect-eventbridge-target-failure-part-1/ When EventBridge cannot deliver a message to a target, there are several ways to get notified. In this blog we discuss an approach of using a dead letter queue https://pubudu.dev/posts/eventbride-to-sqs-cross-region-cross-account-access/ Wed, 17 Sep 2025 00:00:00 +0000 https://pubudu.dev/posts/eventbride-to-sqs-cross-region-cross-account-access/ When EventBridge needs to deliver messages to SQS, depending on cross account or cross region, the solution is different. https://pubudu.dev/posts/how-i-built-a-simple-spelling-game-with-aws-serverless-and-gen-ai/ Tue, 01 Apr 2025 00:00:00 +0000 https://pubudu.dev/posts/how-i-built-a-simple-spelling-game-with-aws-serverless-and-gen-ai/ This blog post explains the process of building a simple spelling game with AWS Serverless and GenAI. https://pubudu.dev/posts/access-api-gw-rest-api-only-from-cloudfront/ Wed, 05 Mar 2025 00:00:00 +0000 https://pubudu.dev/posts/access-api-gw-rest-api-only-from-cloudfront/ In this post, it is discussed how we can secure a AWS API Gateway REST API to accept requests only through CloudFront. https://pubudu.dev/posts/sqs-encryption-options/ Wed, 04 Sep 2024 00:00:00 +0000 https://pubudu.dev/posts/sqs-encryption-options/ SQS supports both in-transit and server side encryption. For serverside encryption, you can from SSE-SQS or SSE-KMS. What exactly is suitable for you depends on your requirement. In this blog, I focus on how to choose the correct SSE method for cross account access. https://pubudu.dev/posts/dead-letter-queue-for-aws-step-functions/ Sun, 26 May 2024 00:00:00 +0000 https://pubudu.dev/posts/dead-letter-queue-for-aws-step-functions/ Step Functions - one of the main Serverless services offered by AWS for workflow orchestration - does not support dead letter queues natively. This is how we can work around to use DLQ with Step Functions. https://pubudu.dev/posts/design-a-mission-critical-serverless-application-for-high-resilience/ Thu, 21 Mar 2024 00:00:00 +0000 https://pubudu.dev/posts/design-a-mission-critical-serverless-application-for-high-resilience/ EBE is one of the mission critical Serverless applications at PostNL. We are maintaining the highest resilience possible to ensure business continuity. This blog explains the steps we took to achive high resilience. https://pubudu.dev/about/ Thu, 04 Jan 2024 23:11:59 +0100 https://pubudu.dev/about/ Hello there 👋 # I am Pubudu Jayawardana and thanks for visiting my personal web site. https://pubudu.dev/posts/call-external-apis-with-oauth-within-step-functions/ Sat, 09 Dec 2023 00:00:00 +0000 https://pubudu.dev/posts/call-external-apis-with-oauth-within-step-functions/ This blog post shows how we can call external HTTPS endpoint within Step Function execution using new native HTTPS integration. https://pubudu.dev/posts/3-ways-to-catch-all-the-events-going-through-the-eventbridge-event-bus/ Wed, 01 Nov 2023 00:00:00 +0000 https://pubudu.dev/posts/3-ways-to-catch-all-the-events-going-through-the-eventbridge-event-bus/ This blog post shows how we can implement 3 different rules that can be used to implement catch-all functionality for a EventBridge event bus. https://pubudu.dev/posts/implement-custom-retry-logic-with-sqs-lambda-part-ii-using-eventbridge-scheduler/ Thu, 26 Oct 2023 00:00:00 +0000 https://pubudu.dev/posts/implement-custom-retry-logic-with-sqs-lambda-part-ii-using-eventbridge-scheduler/ This explains a way to implement custom retry logic with EventBridge Scheduler and Lambda. https://pubudu.dev/posts/implement-custom-retry-logic-with-sqs-lambda-part-i-using-sqs-delayed-messages/ Mon, 16 Oct 2023 00:00:00 +0000 https://pubudu.dev/posts/implement-custom-retry-logic-with-sqs-lambda-part-i-using-sqs-delayed-messages/ This explains a way to implement custom retry logic with SQS and Lambda. https://pubudu.dev/posts/manage-amazon-eventbridge-bus-to-bus-recursive-message-passing/ Tue, 25 Jul 2023 00:00:00 +0000 https://pubudu.dev/posts/manage-amazon-eventbridge-bus-to-bus-recursive-message-passing/ Let’s discuss how to address recursive messages passing between two EventBridge buses. https://pubudu.dev/posts/testing-aws-lambda-recursive-loop-detection/ Tue, 18 Jul 2023 00:00:00 +0000 https://pubudu.dev/posts/testing-aws-lambda-recursive-loop-detection/ This explains the new Lambda recursive loop detection and how to test this new feature. https://pubudu.dev/posts/stay-compliant-with-aws-step-functions-iam-users-access-key-age-notification/ Wed, 14 Jun 2023 00:00:00 +0000 https://pubudu.dev/posts/stay-compliant-with-aws-step-functions-iam-users-access-key-age-notification/ This blog post shows to turn off AppConfig Feature Flag based on system behaviour. https://pubudu.dev/posts/aws-lambda-concurrency-when-sqs-fifo-queue-as-trigger/ Wed, 03 May 2023 00:00:00 +0000 https://pubudu.dev/posts/aws-lambda-concurrency-when-sqs-fifo-queue-as-trigger/ In this blog, it is discussed how Lambda concurrency is determined when a SQS FIFO queue is configured as the trigger. https://pubudu.dev/posts/load-data-from-s3-to-postgres-using-step-functions/ Wed, 03 May 2023 00:00:00 +0000 https://pubudu.dev/posts/load-data-from-s3-to-postgres-using-step-functions/ In this post, I discuss how we can use Step Functions Distributed Maps to parallelise the csv data loading to a database. https://pubudu.dev/posts/self-healing-serverless-app-with-lambda-destinations-and-eventbridge/ Mon, 13 Mar 2023 00:00:00 +0000 https://pubudu.dev/posts/self-healing-serverless-app-with-lambda-destinations-and-eventbridge/ In this blog post, explains how a Lambda based Serverless application reacts to the errors and attempts to re-drive messages to the origin in a controlled manner. https://pubudu.dev/posts/manage-eventbridge-schedules-using-step-functions-wait/ Thu, 02 Mar 2023 00:00:00 +0000 https://pubudu.dev/posts/manage-eventbridge-schedules-using-step-functions-wait/ This is another way of managing EventBridge Schedules withing Step Functions execution. https://pubudu.dev/posts/manage-eventbridge-schedules-using-step-functions/ Fri, 24 Feb 2023 00:00:00 +0000 https://pubudu.dev/posts/manage-eventbridge-schedules-using-step-functions/ With the support of Step Function SDK integrations, we can manage EventBridge Schedules. https://pubudu.dev/posts/split-messages-from-single-sqs-queue-to-multiple-sqs-queues/ Sun, 29 Jan 2023 00:00:00 +0000 https://pubudu.dev/posts/split-messages-from-single-sqs-queue-to-multiple-sqs-queues/ This blog post shows how we can split messages in a SQS queue into mulitple queues usint Amazon EventBride https://pubudu.dev/posts/my-experience-as-a-dev-chat-speaker-at-aws-reinvent/ Tue, 03 Jan 2023 00:00:00 +0000 https://pubudu.dev/posts/my-experience-as-a-dev-chat-speaker-at-aws-reinvent/ In re:Invent 2022, I delivered a talk in the Dev Chats. This explains the process of giving a talk at re:Invent https://pubudu.dev/posts/turn-off-appconfig-feature-flag-automatically/ Mon, 29 Aug 2022 00:00:00 +0000 https://pubudu.dev/posts/turn-off-appconfig-feature-flag-automatically/ This blog post shows to turn off AppConfig Feature Flag based on system behaviour. https://pubudu.dev/posts/aws-step-functions-are-active-executions-affected-when-your-state-machine-gets-updated/ Fri, 10 Jun 2022 20:20:20 +0100 https://pubudu.dev/posts/aws-step-functions-are-active-executions-affected-when-your-state-machine-gets-updated/ Looking into different scenario of SF executions vs state machine updates https://pubudu.dev/posts/simple-leave-management-system-with-aws-serverless/ Tue, 10 May 2022 20:20:20 +0100 https://pubudu.dev/posts/simple-leave-management-system-with-aws-serverless/ This is how I built a simple leave management system using AWS Serverless services https://pubudu.dev/posts/manage-webhooks-at-scale-with-aws-serverless/ Wed, 15 Dec 2021 00:00:00 +0000 https://pubudu.dev/posts/manage-webhooks-at-scale-with-aws-serverless/ Webhook calls are event driven. So, building a webhook management system with Serverless is a great choice. https://pubudu.dev/posts/simple-otp-service-with-aws-serverless/ Mon, 27 Sep 2021 14:30:00 +0200 https://pubudu.dev/posts/simple-otp-service-with-aws-serverless/ This post describes how to implement a simple One Time Password (OTP) system with AWS Serverless services https://pubudu.dev/posts/create-photo-booth-with-aws-serverless/ Fri, 09 Jul 2021 13:17:13 +0200 https://pubudu.dev/posts/create-photo-booth-with-aws-serverless/ This explains how I created a simple photo booth with AWS Serverless services https://pubudu.dev/posts/how-i-built-a-simple-sprint-dashboard-with-aws-amplify/ Sun, 28 Feb 2021 00:00:00 +0000 https://pubudu.dev/posts/how-i-built-a-simple-sprint-dashboard-with-aws-amplify/ This blog post discuss how to build a simple sprint dashboard with AWS Amplify. https://pubudu.dev/posts/how-i-created-a-physical-alarm-to-warn-me-when-my-servers-are-down/ Tue, 27 Oct 2020 00:00:00 +0000 https://pubudu.dev/posts/how-i-created-a-physical-alarm-to-warn-me-when-my-servers-are-down/ This explains the process to create an alarm to trigger when AWS EC2 servers are down https://pubudu.dev/posts/getting-started-with-aws-greengrass-and-raspberry-pi/ Mon, 26 Oct 2020 00:00:00 +0000 https://pubudu.dev/posts/getting-started-with-aws-greengrass-and-raspberry-pi/ Step by step instructions to install AWS Greengrass in a Raspberry Pi https://pubudu.dev/posts/how-i-created-a-serverless-door-bell/ Mon, 28 Sep 2020 00:00:00 +0000 https://pubudu.dev/posts/how-i-created-a-serverless-door-bell/ Explains the steps of me creating a doorbell using Raspberry Pi and AWS Serverless services. https://pubudu.dev/posts/aws-iam-tag-based-permissions/ Wed, 09 Oct 2019 10:17:13 +0200 https://pubudu.dev/posts/aws-iam-tag-based-permissions/ AWS IAM policies provides great amount of facilities in order to set up granular level of permissions. Tag based permissions are one of the cool features supported by IAM. https://pubudu.dev/posts/whitelist-lambda-ip/ Fri, 27 Sep 2019 00:00:00 +0000 https://pubudu.dev/posts/whitelist-lambda-ip/ This blog post discuss how we can allow access from Lambda from an external system by whitelisting IP. https://pubudu.dev/posts/iam-policy-versioning/ Thu, 26 Sep 2019 00:00:00 +0000 https://pubudu.dev/posts/iam-policy-versioning/ Explains how you can manage your IAM Policy versions https://pubudu.dev/posts/understanding-lambda-concurrency/ Thu, 26 Sep 2019 00:00:00 +0000 https://pubudu.dev/posts/understanding-lambda-concurrency/ This blog post explains the behaviour of Lambda when they run simultaneously.