标签：#netcore

Dulu, nyari query yang bikin database spike itu bisa makan berhari-hari. Yang nyari capek, yang nge-fix juga capek. Sekarang? Hitungan jam — dan bonusnya, sambil belajar hal baru juga. Ceritanya begini. Kalau kamu pernah kerja di aplikasi yang pakai ORM (Object-Relational Mapping — semacam "penerjemah otomatis" antara code dan database), pasti familiar sama situasi ini: database tiba-tiba lambat, kamu dapet raw query yang jadi biang kerok, tapi di codebase kamu nulis pakai syntax ORM yang bentuknya beda jauh dari SQL mentah itu. Buat yang belum pernah deal sama ORM, bayangin gini: kamu nulis pesan dalam bahasa Indonesia, lalu ada "penerjemah otomatis" yang convert jadi bahasa Jepang sebelum dikirim ke penerima. Suatu hari ada masalah di pesan yang terkirim — tapi kamu cuma bisa lihat versi bahasa Jepang-nya. Nyari bagian mana dari tulisan Indonesia kamu yang bikin terjemahan-nya bermasalah? Itu effort-nya yang bikin pengen balik tidur aja. Sekarang dengan bantuan Kiro, cukup kasih raw query + akses ke codebase, dia otomatis nyari bagian mana di code yang nge-generate query bermasalah itu. Yang dulu butuh berhari-hari, sekarang bisa selesai dalam hitungan jam — dan itu baru tahap investigasi, belum termasuk fixing-nya. Ceritanya Kenapa Bisa Pakai Kiro Akhir-akhir ini lagi aktif pakai Kiro di tempat kerja. Awal tahun lalu kantor dapat credits melalui program Kiro for Startup , jadi ya sekalian dimaksimalkan. Selain buat debug dan explore query di MS SQL Server, kadang pakai Kiro juga buat analisa log AWS CloudWatch — sambil kasih context aplikasi yang running biar analisa-nya lebih akurat dan gak generic. Di tulisan kali ini, saya mau sharing gimana pakai Kiro sebagai partner beberapa minggu terakhir buat improve query performance di aplikasi .NET Core. Kenapa "partner"? Karena Kiro-nya gak boleh langsung akses ke database — jadi wajib melalui perantara saya. Kita discuss, kolaborasi, dan nge-solve bareng. Bukan AI yang dikasih tombol terus disuruh jalan sendiri. Wakt

Blazor SSR Gets Client-Side Validation in .NET 11 Preview 5 If you've built Blazor Server-Side Rendering (SSR) forms, you know the pain: a user fills out a form, hits submit, the form posts to the server, the server runs validation, and only then does the user see the "This field is required" message next to the empty email field. That round-trip latency adds up. It breaks the immediacy users expect from modern web apps. .NET 11 Preview 5 fixes this. Blazor SSR forms now get instant, in-browser validation feedback — no server required. The server renders your validation rules as metadata, and Blazor's JavaScript enforces them client-side. Same DataAnnotationsValidator component you already use. Zero code changes needed. Let's break down how it works. Before .NET 11: The SSR Validation Gap In .NET 8 and 9, Blazor SSR rendered HTML on the server and sent it down. Validation only ran server-side — on form submission. If a field was invalid, the whole form posted to the server, came back with validation messages, and re-rendered. Interactive Blazor modes (Server, WebAssembly, Auto) had instant client-side validation because an active SignalR circuit or WASM runtime ran the validation logic locally. But SSR mode — the simplest, most performant option — was left out. The result? Developers who chose SSR Blazor for its simplicity had to choose between: Accepting the laggy validation UX Adding a second JavaScript validation library (and maintaining two validation rulesets) Re-architecting to use an interactive render mode None of these are great options. What Changed in .NET 11 Preview 5 The .NET team shipped two PRs ( #66441 and #66420 ) that bring unobtrusive client-side validation to Blazor SSR forms. The key insight: The .NET model stays the single source of truth. On form render, the server serializes your DataAnnotations validation rules into HTML metadata attributes. Blazor's JavaScript reads those attributes and applies them client-side — the same approach ASP.NET M

What can I say. Anyone claiming that F# is good mostly for finance and data processing and C# for everything else, has probably never written a single line of practical F# code. In previous two parts of the article, I tried to demonstrate that with F# you can achieve the same goals as with C#, but with less verbose, repetitive, structural code. How it started. At some point, developers realized that global state with unrestricted data access causes many side effects, producing insecure, error-prone, and hard-to-maintain code as software grows larger. That is when the idea emerged to bring data and the code operating on it together into a single unit, restricting direct access to the unit’s internal state and making software more secure and predictable. This is how data encapsulation was born. Alongside encapsulation, abstraction was introduced — the process of hiding how behavior works. Encapsulation ( hiding data ) and abstraction ( hiding behavior ) remain two foundational pillars of Object-Oriented Programming. And that is how OOP has worked ever since — developers bring data and behavior together ( classes ) and define abstractions for them ( interfaces ). For example, for C# developers — including myself — this has become a daily routine. And we rarely question it, because OOP languages like C# leave us little choice but to structure code this way. But if you ask yourself whether this repetitive routine is always necessary, the answer is — no. You don’t need OOP concepts to build stateless, streamlined request–response, data-processing pipelines, because in such systems there is no long-lived state to hide and protect. You have a request, and almost immediately you have a response. After that, everything is gone. That is what I tried to demonstrate in the first two parts of this article by applying FP concepts. And even if you have a classical desktop application, you don’t always need to approach it in an OOP way. Functional programming handles side effects no