Daily micro-tips for C#, SQL, performance, and scalable backend engineering.
[] Instead of new List { } Python has [1,2,3]. C# finally gets collection expressions! Same syntax for arrays, lists, spans. More readable, less typing. ❌ Old Way (Verbose) int[] arr = new int[] { 1, 2, 3 }; List list = new List { “a”, “b”, “c” }; Span span = new int[] { […]
🎯 Dependency Injection Just Got Cleaner private readonly ILogger _logger; + constructor = 4 lines. Primary constructors do it in 1 line. C# 12 changes everything. ❌ Old Way (12 lines) public class OrderService { private readonly IOrderRepository _repository; private readonly ILogger _logger; private readonly IEmailService _emailService; public OrderService( IOrderRepository repository, ILogger logger, IEmailService emailService) […]
🔄 One Query: Insert or Update Check if exists → Update or Insert = 2 queries. UPSERT does it in one. Faster, atomic, race-condition free. 📝 PostgreSQL (ON CONFLICT) — Basic UPSERT (update if conflict) INSERT INTO users (id, name, email, last_login) VALUES (1, ‘Alice’, ‘alice@example.com’, NOW()) ON CONFLICT (id) DO UPDATE SET name = […]
🔄 V1, V2, V3 — All Running Simultaneously Change API = break clients. API versioning lets you run multiple versions. Old clients stay on V1, new clients use V2. No downtime. 📝 Setup Versioning dotnet add package Asp.Versioning.Mvc dotnet add package Asp.Versioning.Mvc.ApiExplorer // Program.cs builder.Services.AddApiVersioning(options => { options.DefaultApiVersion = new ApiVersion(1, 0); options.AssumeDefaultVersionWhenUnspecified = true; […]
⚡ git st → git status Typing ‘git status –short –branch’ every time? Git aliases create shortcuts. Save keystrokes, create powerful composite commands. 📝 Create Aliases # Basic aliases git config –global alias.st status git config –global alias.co checkout git config –global alias.br branch git config –global alias.ci commit git config –global alias.df diff git […]
📡 One-Way Real-Time Updates Need live updates but not bidirectional? EventSource (SSE) is simpler than WebSockets. Auto-reconnects. Built-in retry. Perfect for dashboards, notifications. 📝 Client-Side const eventSource = new EventSource(‘/api/events’); // Listen for messages eventSource.onmessage = (event) => { const data = JSON.parse(event.data); console.log(‘Update:’, data); updateUI(data); }; // Listen for specific event type eventSource.addEventListener(‘notification’, (event) […]
📊 Native GroupBy Finally Arrived _.groupBy() required Lodash. Object.groupBy() is now native. Group arrays by any criteria. No more manual reduce hacks. 📝 Basic Usage const users = [ { name: ‘Alice’, role: ‘admin’ }, { name: ‘Bob’, role: ‘user’ }, { name: ‘Charlie’, role: ‘admin’ }, { name: ‘Diana’, role: ‘user’ } ]; // […]
✔️ Validate Without JavaScript pattern attribute validates input with regex. Built-in error messages, no JS needed. Works on mobile keyboards too. 📝 Common Patterns <!– US Phone Number –> <input type=”tel” pattern=”[0-9]{3}-[0-9]{3}-[0-9]{4}” placeholder=”123-456-7890″> <!– Zip Code (US) –> <input type=”text” pattern=”[0-9]{5}(-[0-9]{4})?” placeholder=”12345″> <!– Username (letters, numbers, underscore) –> <input type=”text” pattern=”[A-Za-z0-9_]{3,20}” title=”3-20 characters: letters, numbers, […]
📐 No More Padding Hack Remember padding-bottom: 56.25% for 16:9? aspect-ratio property does it natively. Videos, images, cards — perfect proportions. 📝 Basic Usage /* Square */ .square { aspect-ratio: 1 / 1; background: blue; width: 200px; } /* 16:9 video container */ .video-container { aspect-ratio: 16 / 9; background: black; width: 100%; } /* […]
🔕 Silence the Distractions Every Slack ping breaks flow. Focus Assist hides all notifications during focus time. Only priority contacts get through. 🔧 Enable Focus Assist Settings → System → Focus Assist Three modes: – Off: All notifications (default) – Priority only: Only from specified contacts/apps – Alarms only: No notifications except alarms Quick toggle: […]
🧪 AI Writes Your Tests Writing tests is tedious. AI generates unit tests from function signatures. Edge cases, error handling, happy paths — all covered. 📝 The Prompt Generate comprehensive unit tests for this function: [Paste function code here] Testing framework: [Jest / pytest / NUnit / xUnit] Language: [JavaScript / Python / C# / […]
🗑️ Your Disk is Full of Dead Containers Stopped containers, unused images, unused volumes — they eat disk space. docker system prune cleans everything in one command. 📝 Prune Commands # Clean everything (containers, images, networks, build cache) docker system prune -a –volumes # Stop and remove all stopped containers docker container prune # Remove […]
📊 Don’t Let One Team Hog All Resources One namespace uses all CPU? Others starve. Resource quotas limit total CPU, memory, storage per namespace. Fair sharing for multi-tenant clusters. 📝 Basic Quota apiVersion: v1 kind: ResourceQuota metadata: name: namespace-quota namespace: development spec: hard: requests.cpu: “4” requests.memory: “8Gi” limits.cpu: “8” limits.memory: “16Gi” persistentvolumeclaims: “10” pods: “20” […]
📦 Drag-and-Drop Everywhere Widgets only in sidebar? Not anymore. register_sidebar() creates widget areas anywhere: header, footer, after content, before comments. 📝 Register Sidebars // functions.php function custom_widget_areas() { // Footer widget area register_sidebar(array( ‘name’ => ‘Footer Widget Area’, ‘id’ => ‘footer-widgets’, ‘description’ => ‘Appears at the bottom of every page’, ‘before_widget’ => ”, ‘after_widget’ => […]
📁 100 Layers? Collapse Them! Scrolling through endless layers is a nightmare. Layer Groups organize related layers. Collapse, rename, color-code, apply effects to entire group. 📝 Create Layer Group Method 1: Layer → New → Group (Ctrl + G) Method 2: Select multiple layers → Ctrl + G Method 3: Drag layers onto folder icon […]
⏪ Ctrl + – Takes You Back to Where You Were Jumped to definition? Scrolled away? Navigate Backward (Ctrl + -) returns to your previous cursor position. Like a browser back button for your code. ⌨️ Shortcuts Ctrl + – → Navigate Backward (go to previous cursor location) Ctrl + Shift + – → Navigate […]
⚡ Zero Allocation Until You Log Logging with string interpolation allocates memory even when log level is off. Interpolated string handlers defer formatting until needed. ❌ Regular Interpolation (Always Allocates) // Even if log level is Error and this is Debug // string is still allocated! _logger.LogDebug($”User {userId} logged in at {DateTime.Now}”); // 2 allocations: […]
🎯 One Line Null Check if (arg == null) throw new ArgumentNullException(nameof(arg)); is so 2019. Throw helpers do it in one line. Less code, fewer bugs. ❌ Old Way (4 lines) public void Process(string name, int? age) { if (name == null) throw new ArgumentNullException(nameof(name)); if (age == null) throw new ArgumentNullException(nameof(age)); // Logic here […]
📊 ROWS BETWEEN Is the Secret Sauce Running total? Moving average? Cumulative sum? Window frame clauses define exactly which rows to include. Powerful analytics in pure SQL. 📝 Running Total (Cumulative Sum) SELECT order_date, amount, SUM(amount) OVER ( ORDER BY order_date ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW ) AS running_total FROM orders; — UNBOUNDED […]
⚡ 1000x Faster with One Attribute Same endpoint called repeatedly? Database query every time? Output caching stores HTTP responses. One line of code, huge performance. 🔧 Setup (.NET 7+) // Program.cs builder.Services.AddOutputCache(); app.UseOutputCache(); // Controller [ApiController] [Route(“api/[controller]”)] public class ProductsController : ControllerBase { [HttpGet] [OutputCache(Duration = 60)] // Cache for 60 seconds public async Task […]
🔍 Search Only Tracked Files, Faster grep searches everything, including .git folder. git grep searches only tracked files. Respects .gitignore. Much faster. 📝 Basic Search # Search for word in tracked files git grep “functionName” # Search with line numbers git grep -n “TODO” # Search with context (2 lines before/after) git grep -B 2 […]
⚙️ Heavy Math? Don’t Block UI! JavaScript runs on main thread. Long loops freeze the page. Web Workers run in background threads. UI stays responsive. 📝 Basic Worker // main.js const worker = new Worker(‘worker.js’); worker.postMessage({ data: largeArray, operation: ‘process’ }); worker.onmessage = (event) => { console.log(‘Result:’, event.data); updateUI(event.data); }; worker.onerror = (error) => { […]
🌍 No More Moment.js Dates, numbers, currencies, plurals — all have different formats per locale. Intl API is built-in. No libraries needed. 📝 Date Formatting const date = new Date(); // US English new Intl.DateTimeFormat(‘en-US’).format(date); // “12/31/2024” // UK English new Intl.DateTimeFormat(‘en-GB’).format(date); // “31/12/2024” // German new Intl.DateTimeFormat(‘de-DE’).format(date); // “31.12.2024” // Japanese new Intl.DateTimeFormat(‘ja-JP’).format(date); // […]
✏️ Edit Any Element Like a Text Editor Need inline editing? contenteditable makes any element editable. divs, spans, whole pages. Like a text editor on the web. 📝 Basic Usage <div contenteditable=”true”> Click me and edit this text directly! </div> <h1 contenteditable=”true”>Editable Title</h1> <p contenteditable=”true”> This paragraph can be edited by users. Great for notes, […]
🌍 margin-left breaks in RTL languages Arabic, Hebrew read right-to-left. CSS Logical Properties use ‘inline’ and ‘block’ instead of ‘left’ and ‘right’. Works for any language. ❌ Physical Properties .sidebar { margin-left: 20px; padding-right: 10px; text-align: left; border-left: 1px solid; } // In RTL, all these are wrong! ✅ Logical Properties .sidebar { margin-inline-start: 20px; […]
💾 JBOD → RAID Without Hardware Multiple external drives? Different sizes? Storage Spaces pools them together. Add mirroring, parity, or just combine capacity. 📝 Create Storage Pool Control Panel → Storage Spaces → Create a new pool Or PowerShell: # List available disks Get-PhysicalDisk | Where-Object CanPool -eq $True # Create pool New-StoragePool -FriendlyName “MediaPool” […]
🔄 “Invalid token”? AI Explains What It Actually Means Error messages are often cryptic. AI translates them into plain English, suggests fixes, and explains the real issue. 📝 The Prompt I received this error message: [Paste error message here] Please: 1. Explain what this error means in plain English 2. What is the most likely […]
🐳 One Build, All Architectures Intel Mac, Apple Silicon, ARM servers, AMD servers — different architectures. Docker Buildx builds for all from a single machine. 🔧 Setup Buildx # Create new builder instance (supports multiple platforms) docker buildx create –name multiarch –use # Bootstrap builder docker buildx inspect –bootstrap # Verify platforms docker buildx ls […]
🚫 Dedicated Nodes for Special Workloads Some nodes have GPUs. Some are spot instances. Taints repel pods. Tolerations allow them. Control exactly where workloads run. 📝 Add Taint to Node # Taint effects: # NoSchedule: Pods without toleration won’t be scheduled # PreferNoSchedule: Avoid if possible # NoExecute: Evict existing pods without toleration # Add […]
⚡ 80% of Options Load on Every Page WordPress loads all ‘autoload’ options on every request. Many are never used. Clean your autoloaded options for faster admin. 📝 Check Autoloaded Options — SQL Query to see autoloaded options SELECT COUNT(*), SUM(LENGTH(option_value)) as total_size FROM wp_options WHERE autoload = ‘yes’; — List largest autoloaded options SELECT […]