Practical programming notes on Java, .NET, React, Python, Flutter and the tools around them.https://emirbalic.com/https://emirbalic.com/react-preparing-applications-for-production-deployment/https://emirbalic.com/react-preparing-applications-for-production-deployment/A React application that works in development is not automatically ready for production. Deployment introduces concerns involving build configuration, runtime environment…Fri, 30 Oct 2026 09:00:00 GMThttps://emirbalic.com/python-improving-test-reliability-with-fixtures-and-factories/https://emirbalic.com/python-improving-test-reliability-with-fixtures-and-factories/Automated tests become harder to maintain when every test contains lengthy setup code or depends on data created by another test. Python testing tools such as pytest provide…Tue, 27 Oct 2026 09:00:00 GMThttps://emirbalic.com/flutter-reducing-widget-rebuild-costs-through-better-state-boundaries/https://emirbalic.com/flutter-reducing-widget-rebuild-costs-through-better-state-boundaries/Flutter's declarative UI model rebuilds widgets when their relevant state changes. Rebuilding widgets is normal and often inexpensive, but poorly organized state can cause…Fri, 23 Oct 2026 09:00:00 GMThttps://emirbalic.com/aspnet-core-designing-consistent-api-validation-responses/https://emirbalic.com/aspnet-core-designing-consistent-api-validation-responses/API clients need predictable responses when requests contain invalid data. If each endpoint reports validation errors differently, client applications must implement special…Tue, 20 Oct 2026 09:00:00 GMThttps://emirbalic.com/java-applying-dependency-injection-without-overcomplicating-your-design/https://emirbalic.com/java-applying-dependency-injection-without-overcomplicating-your-design/Dependency injection helps Java applications separate business logic from the concrete services it uses. Instead of constructing every dependency inside a class, an application…Fri, 16 Oct 2026 09:00:00 GMThttps://emirbalic.com/react-building-reliable-multi-step-forms/https://emirbalic.com/react-building-reliable-multi-step-forms/Multi-step forms help users complete complex tasks without facing every field at once. They are common in onboarding flows, checkout processes, account setup, and configuration…Tue, 13 Oct 2026 09:00:00 GMThttps://emirbalic.com/python-designing-reliable-scheduled-jobs-with-apscheduler/https://emirbalic.com/python-designing-reliable-scheduled-jobs-with-apscheduler/Scheduled jobs are useful for generating reports, cleaning temporary files, synchronizing data, and performing routine maintenance. Python developers can automate these tasks…Fri, 09 Oct 2026 09:00:00 GMThttps://emirbalic.com/developer-workflow-building-a-sustainable-on-call-runbook/https://emirbalic.com/developer-workflow-building-a-sustainable-on-call-runbook/When a production incident occurs, developers and operators need to make decisions quickly with incomplete information. An on-call runbook reduces the need to reconstruct…Tue, 06 Oct 2026 09:00:00 GMThttps://emirbalic.com/aspnet-core-preventing-duplicate-requests-with-idempotency-keys/https://emirbalic.com/aspnet-core-preventing-duplicate-requests-with-idempotency-keys/Clients sometimes retry requests because a network connection fails, a timeout occurs, or the user clicks a button more than once. For operations such as creating an order or…Fri, 02 Oct 2026 09:00:00 GMThttps://emirbalic.com/java-managing-database-schema-migrations-safely/https://emirbalic.com/java-managing-database-schema-migrations-safely/Database schemas evolve as applications add features, change relationships, and improve performance. Making these changes safely requires more than writing SQL that works on a…Tue, 29 Sep 2026 09:00:00 GMThttps://emirbalic.com/react-making-tables-accessible-and-easier-to-maintain/https://emirbalic.com/react-making-tables-accessible-and-easier-to-maintain/Tables are a common way to present structured information such as invoices, reports, users, and product inventories. A table may look correct visually while remaining difficult…Fri, 25 Sep 2026 09:00:00 GMThttps://emirbalic.com/python-using-structured-concurrency-for-safer-async-tasks/https://emirbalic.com/python-using-structured-concurrency-for-safer-async-tasks/Python's asyncio makes it possible to run many I/O-bound operations without blocking a thread for every wait. However, creating independent tasks without managing their…Tue, 22 Sep 2026 09:00:00 GMThttps://emirbalic.com/flutter-handling-loading-empty-error-and-success-states/https://emirbalic.com/flutter-handling-loading-empty-error-and-success-states/A screen that loads remote data rarely has only one meaningful state. It may be waiting for a response, displaying results, showing that no records exist, or reporting a…Fri, 18 Sep 2026 09:00:00 GMThttps://emirbalic.com/aspnet-core-handling-configuration-changes-safely/https://emirbalic.com/aspnet-core-handling-configuration-changes-safely/Configuration settings influence how ASP.NET Core applications connect to dependencies, apply feature flags, and control runtime behavior. Some values remain constant for the…Tue, 15 Sep 2026 09:00:00 GMThttps://emirbalic.com/java-choosing-between-synchronous-and-asynchronous-processing/https://emirbalic.com/java-choosing-between-synchronous-and-asynchronous-processing/Java applications frequently perform operations that wait for external systems, such as calling APIs, querying databases, or publishing messages. Choosing between synchronous…Fri, 11 Sep 2026 09:00:00 GMThttps://emirbalic.com/react-improving-component-reuse-without-overengineering/https://emirbalic.com/react-improving-component-reuse-without-overengineering/Reusable components help React applications maintain a consistent interface and reduce duplicated code. However, not every repeated block needs a universal abstraction.…Tue, 08 Sep 2026 09:00:00 GMThttps://emirbalic.com/python-building-maintainable-data-validation-pipelines/https://emirbalic.com/python-building-maintainable-data-validation-pipelines/Data validation is essential whenever an application receives information from users, external APIs, files, or databases. Without clear validation rules, invalid data can…Fri, 04 Sep 2026 09:00:00 GMThttps://emirbalic.com/developer-workflow-creating-a-practical-definition-of-done/https://emirbalic.com/developer-workflow-creating-a-practical-definition-of-done/Software teams often disagree about when a task is truly complete. A feature may work on one developer's machine but lack tests, documentation, error handling, or deployment…Tue, 01 Sep 2026 09:00:00 GMThttps://emirbalic.com/aspnet-core-designing-reliable-health-checks-for-dependencies/https://emirbalic.com/aspnet-core-designing-reliable-health-checks-for-dependencies/A web application may respond to HTTP requests while being unable to reach its database, message broker, or another critical dependency. Health checks help operators and…Fri, 28 Aug 2026 09:00:00 GMThttps://emirbalic.com/java-improving-application-configuration-without-hardcoding-values/https://emirbalic.com/java-improving-application-configuration-without-hardcoding-values/Application configuration changes across development, testing, staging, and production. Database URLs, API endpoints, feature flags, and timeouts should not require source-code…Tue, 25 Aug 2026 09:00:00 GMThttps://emirbalic.com/react-building-search-interfaces-with-debouncing-and-cancellation/https://emirbalic.com/react-building-search-interfaces-with-debouncing-and-cancellation/Search interfaces often send requests as users type. Without careful handling, a fast typist can trigger many requests, overload an API, and see results arrive in the wrong…Fri, 21 Aug 2026 09:00:00 GMThttps://emirbalic.com/python-managing-database-connections-in-web-applications/https://emirbalic.com/python-managing-database-connections-in-web-applications/Database connections are limited resources. Opening a new connection for every small operation can add latency and create unnecessary load, while holding connections…Tue, 18 Aug 2026 09:00:00 GMThttps://emirbalic.com/flutter-making-navigation-predictable-in-growing-applications/https://emirbalic.com/flutter-making-navigation-predictable-in-growing-applications/Navigation often starts simply: a button opens a second screen, and a back button returns to the first. As an application grows, it may need nested navigation, deep links,…Fri, 14 Aug 2026 09:00:00 GMThttps://emirbalic.com/aspnet-core-using-output-caching-to-improve-api-performance/https://emirbalic.com/aspnet-core-using-output-caching-to-improve-api-performance/API performance is not always improved by rewriting database queries or adding more servers. Sometimes the same expensive response is generated repeatedly even though its…Tue, 11 Aug 2026 09:00:00 GMThttps://emirbalic.com/java-designing-api-clients-with-clear-error-handling/https://emirbalic.com/java-designing-api-clients-with-clear-error-handling/Applications that consume external APIs must handle more than successful responses. Networks fail, services return error status codes, response bodies may be malformed, and…Fri, 07 Aug 2026 09:00:00 GMThttps://emirbalic.com/react-preventing-memory-leaks-in-components-and-effects/https://emirbalic.com/react-preventing-memory-leaks-in-components-and-effects/React components often interact with resources that exist outside React's rendering system. Examples include timers, event listeners, subscriptions, network requests, and…Tue, 04 Aug 2026 09:00:00 GMThttps://emirbalic.com/python-building-maintainable-command-line-tools-with-argparse/https://emirbalic.com/python-building-maintainable-command-line-tools-with-argparse/Command-line tools are an effective way to automate repetitive development tasks, manage data, and simplify operational workflows. Python makes it straightforward to build…Fri, 31 Jul 2026 09:00:00 GMThttps://emirbalic.com/developer-workflow-creating-a-practical-technical-debt-reduction-plan/https://emirbalic.com/developer-workflow-creating-a-practical-technical-debt-reduction-plan/Technical debt is often discussed as a single backlog of things that need cleaning up. In reality, it includes many different problems: fragile tests, duplicated logic,…Tue, 28 Jul 2026 09:00:00 GMThttps://emirbalic.com/aspnet-core-protecting-apis-with-policy-based-authorization/https://emirbalic.com/aspnet-core-protecting-apis-with-policy-based-authorization/Authentication answers the question, “Who is making this request?” Authorization answers a different question: “Is this identity allowed to perform this operation?”Fri, 24 Jul 2026 09:00:00 GMThttps://emirbalic.com/java-practical-observability-with-structured-logging/https://emirbalic.com/java-practical-observability-with-structured-logging/When a production application fails, developers need to understand what happened, where it happened, and how many users were affected.Tue, 21 Jul 2026 09:00:00 GMThttps://emirbalic.com/react-managing-complex-ui-state-with-reducers/https://emirbalic.com/react-managing-complex-ui-state-with-reducers/React's useState hook is an excellent choice for simple state. As components grow, however, multiple state variables may become tightly coupled.Fri, 17 Jul 2026 09:00:00 GMThttps://emirbalic.com/python-improving-api-reliability-with-timeouts-and-retries/https://emirbalic.com/python-improving-api-reliability-with-timeouts-and-retries/A Python application that calls an external API depends on another system's availability and response time. Even reliable services can experience temporary network failures or…Tue, 14 Jul 2026 09:00:00 GMThttps://emirbalic.com/flutter-building-forms-that-are-easy-to-validate-and-maintain/https://emirbalic.com/flutter-building-forms-that-are-easy-to-validate-and-maintain/Forms are central to mobile applications. Registration, checkout, profile editing, and settings screens all rely on collecting user input.Fri, 10 Jul 2026 09:00:00 GMThttps://emirbalic.com/aspnet-core-designing-api-pagination-that-scales/https://emirbalic.com/aspnet-core-designing-api-pagination-that-scales/An API that returns every matching record may work during early development. As the dataset grows, however, the same endpoint can become expensive in database work, response…Tue, 07 Jul 2026 09:00:00 GMThttps://emirbalic.com/java-using-records-and-immutable-data-models-effectively/https://emirbalic.com/java-using-records-and-immutable-data-models-effectively/Java applications often contain classes whose primary purpose is to carry data between layers. Traditional implementations can require considerable boilerplate for…Fri, 03 Jul 2026 09:00:00 GMThttps://emirbalic.com/react-designing-accessible-dropdown-menus/https://emirbalic.com/react-designing-accessible-dropdown-menus/Dropdown menus are common in modern interfaces. They provide access to navigation, account settings, filters, and contextual actions without permanently occupying screen space.Tue, 30 Jun 2026 09:00:00 GMThttps://emirbalic.com/python-building-reliable-email-workflows-with-background-tasks/https://emirbalic.com/python-building-reliable-email-workflows-with-background-tasks/Sending an email seems simple until an application needs to handle slow providers, temporary network failures, duplicate requests, and delivery errors. If email delivery…Fri, 26 Jun 2026 09:00:00 GMThttps://emirbalic.com/developer-workflow-preparing-a-software-project-for-a-safe-release/https://emirbalic.com/developer-workflow-preparing-a-software-project-for-a-safe-release/A release is more than merging code and deploying a new version. It is a controlled change to a running system, and even a small update can introduce problems if configuration,…Tue, 23 Jun 2026 09:00:00 GMThttps://emirbalic.com/aspnet-core-building-reliable-file-downloads-and-streaming-responses/https://emirbalic.com/aspnet-core-building-reliable-file-downloads-and-streaming-responses/File downloads are common in web applications, from report exports to document delivery and media processing. The implementation must consider more than returning a file:…Fri, 19 Jun 2026 09:00:00 GMThttps://emirbalic.com/java-writing-maintainable-integration-tests-with-testcontainers/https://emirbalic.com/java-writing-maintainable-integration-tests-with-testcontainers/Unit tests are valuable for verifying isolated business logic, but they cannot prove that an application works correctly with its actual database, message broker, or other…Tue, 16 Jun 2026 09:00:00 GMThttps://emirbalic.com/react-choosing-between-client-side-and-server-side-data-fetching/https://emirbalic.com/react-choosing-between-client-side-and-server-side-data-fetching/Fetching data is a core part of most React applications. The decision to load it on the client or server affects performance, caching, security, user experience, and…Fri, 12 Jun 2026 09:00:00 GMThttps://emirbalic.com/python-preventing-race-conditions-in-concurrent-applications/https://emirbalic.com/python-preventing-race-conditions-in-concurrent-applications/Concurrency allows an application to make progress on multiple tasks, but it also introduces the possibility that operations interfere with one another.Tue, 09 Jun 2026 09:00:00 GMThttps://emirbalic.com/flutter-improving-app-startup-time-without-sacrificing-maintainability/https://emirbalic.com/flutter-improving-app-startup-time-without-sacrificing-maintainability/The first moments after a user opens an application strongly influence how responsive it feels. A slow startup can make an otherwise polished app seem unreliable.Fri, 05 Jun 2026 09:00:00 GMThttps://emirbalic.com/aspnet-core-implementing-background-processing-with-hosted-services/https://emirbalic.com/aspnet-core-implementing-background-processing-with-hosted-services/Not every task should run inside an HTTP request. Sending notifications, processing scheduled work, and performing periodic maintenance may take longer than a request should…Tue, 02 Jun 2026 09:00:00 GMThttps://emirbalic.com/java-understanding-memory-leaks-in-garbage-collected-applications/https://emirbalic.com/java-understanding-memory-leaks-in-garbage-collected-applications/Java's garbage collector automatically reclaims objects that are no longer reachable. This removes much of the manual memory-management burden found in lower-level languages.Fri, 29 May 2026 09:00:00 GMThttps://emirbalic.com/react-building-reusable-modal-dialogs-with-accessibility-in-mind/https://emirbalic.com/react-building-reusable-modal-dialogs-with-accessibility-in-mind/Modal dialogs are useful for confirmation prompts, editing forms, and focused tasks. However, a modal that looks correct can still be difficult to use if keyboard navigation,…Tue, 26 May 2026 09:00:00 GMThttps://emirbalic.com/python-designing-clean-service-layers-in-fastapi-applications/https://emirbalic.com/python-designing-clean-service-layers-in-fastapi-applications/FastAPI makes it easy to create API endpoints, but an application can become difficult to maintain when database queries, validation, business rules, and external service calls…Fri, 22 May 2026 09:00:00 GMThttps://emirbalic.com/developer-productivity-creating-a-sustainable-technical-debt-reduction-plan/https://emirbalic.com/developer-productivity-creating-a-sustainable-technical-debt-reduction-plan/Technical debt is often discussed as if it were a single list of bad code that must eventually be rewritten. In practice, it includes many different trade-offs: outdated…Tue, 19 May 2026 09:00:00 GMThttps://emirbalic.com/aspnet-core-protecting-apis-with-secure-authentication-and-authorization-policies/https://emirbalic.com/aspnet-core-protecting-apis-with-secure-authentication-and-authorization-policies/Authentication and authorization are related, but they solve different problems.Fri, 15 May 2026 09:00:00 GMThttps://emirbalic.com/java-designing-resilient-message-consumers-with-retries-and-dead-letter-queues/https://emirbalic.com/java-designing-resilient-message-consumers-with-retries-and-dead-letter-queues/Message queues help applications process work asynchronously, but consumers must handle failures. A database may be temporarily unavailable, a downstream service may time out,…Tue, 12 May 2026 09:00:00 GMT