Daily micro-tips for C#, SQL, performance, and scalable backend engineering.
System.Text.Json is fast but MemoryPack uses binary format for extreme performance. Install: dotnet add package MemoryPack Define Serializable Type: [MemoryPackable] public partial class User { public int Id { get; set; } public string Name { get; set; } = string.Empty; public string Email { get; set; } = string.Empty; public DateTime CreatedAt { get; […]
params arrays create heap allocation on every call. C# 13 allows params with Span for zero-allocation variable args. Old Way (Allocates): // params creates new int[] on every call public int Sum(params int[] numbers) { return numbers.Sum(); } // Called 1 million times = 1 million array allocations! Sum(1, 2, 3); New Way – C# […]
Creating and destroying heavy objects (StringBuilder, MemoryStream) repeatedly wastes memory. ObjectPool reuses them. Install: dotnet add package Microsoft.Extensions.ObjectPool Setup: // Program.cs builder.Services.AddSingleton(); builder.Services.AddSingleton(sp => { var provider = sp.GetRequiredService(); return provider.CreateStringBuilderPool(); }); Use in Service: public class TextService(ObjectPool pool) { public string BuildLargeText(IEnumerable items) { // Get StringBuilder from pool (reuse, no new allocation) var […]
Creating expensive objects at startup wastes resources if they’re never used. Lazy defers creation until first access. Without Lazy: public class ReportService { // Created on class instantiation even if never used private readonly PdfGenerator _pdfGen = new PdfGenerator(); // Heavy! private readonly ExcelExporter _excelExporter = new ExcelExporter(); // Heavy! public void GeneratePdf() => _pdfGen.Generate(); […]
Collecting multiple rows into one comma-separated string used to require cursors. STRING_AGG does it in one line. Basic Usage: — Get all tags for each post SELECT PostId, STRING_AGG(TagName, ‘, ‘) AS Tags FROM PostTags GROUP BY PostId; — Result: — PostId Tags — 1 CSS, HTML, JavaScript — 2 SQL, Database, Performance With Ordering: […]
Regular index on status column with 95% ‘active’ rows is inefficient. Filter index to index only relevant rows. Problem – Full Index: — Index includes ALL rows (95% active, 5% inactive) CREATE INDEX IX_Orders_Status ON Orders(Status); — Query only needs inactive SELECT * FROM Orders WHERE Status = ‘inactive’; — Reads huge index to find […]
Throwing exceptions for business logic (user not found, invalid input) is expensive. Result pattern is cleaner and faster. Define Result Type: public class Result { public T? Value { get; } public string? Error { get; } public bool IsSuccess { get; } private Result(T value) { Value = value; IsSuccess = true; } private […]
Reading config with magic strings breaks on typos. IOptions pattern gives strongly-typed, validated config. Define Config Class: public class EmailSettings { public string SmtpHost { get; set; } = string.Empty; public int SmtpPort { get; set; } public string Username { get; set; } = string.Empty; public string Password { get; set; } = string.Empty; […]
Team uses Windows and Mac? Mixed line endings (CRLF/LF) cause constant unnecessary diffs. Fix with .gitattributes. Create .gitattributes in repo root: # Normalize all text files to LF in repo * text=auto # Force LF for these file types *.js text eol=lf *.ts text eol=lf *.css text eol=lf *.html text eol=lf *.json text eol=lf # […]
Want to add context to old commits without rewriting history? Git notes attach metadata to any commit. Add Note to Commit: # Add note to last commit git notes add -m “Reviewed by John. Deployed to staging 2024-03-15” # Add note to specific commit git notes add -m “This fixed the prod outage on Black […]
Users lose access when offline. Cache API stores assets so app works without internet. Register Service Worker: // main.js if (‘serviceWorker’ in navigator) { navigator.serviceWorker.register(‘/sw.js’); } Service Worker (sw.js): const CACHE = ‘v1’; const ASSETS = [‘/’, ‘/styles.css’, ‘/app.js’, ‘/logo.png’]; // Install: cache assets self.addEventListener(‘install’, event => { event.waitUntil( caches.open(CACHE).then(cache => cache.addAll(ASSETS)) ); }); // […]
Private class fields with # work but WeakMap provides better encapsulation and no memory leaks. Private Fields Approach: class Counter { #count = 0; // Private increment() { this.#count++; } get value() { return this.#count; } } WeakMap Approach: const _private = new WeakMap(); class Counter { constructor() { _private.set(this, { count: 0, history: [] […]
Showing form calculation results in a div is hacky. HTML5 output element is semantic and accessible. Basic Example: <form oninput=”result.value = parseInt(a.value) + parseInt(b.value)”> <input type=”number” id=”a” value=”0″> + <input type=”number” id=”b” value=”0″> = <output name=”result” for=”a b”>0</output> </form> Tips Calculator: <form oninput=”tip.value = (bill.value * pct.value / 100).toFixed(2)”> Bill: <input type=”number” id=”bill”> Tip %: […]
Headlines with one word on last line look unprofessional. text-wrap: balance distributes text evenly across lines. The Problem: This is a Long Heading That Ends With Just One Awkward Word Alone The Fix: h1, h2, h3 { text-wrap: balance; } Result: This is a Long Heading That Ends Much More Nicely Balanced Also Available: p […]
Something using all your bandwidth or disk but Task Manager doesn’t show what? Resource Monitor has the details. Open: Task Manager → Performance tab → Open Resource Monitor Or: Start → Search “Resource Monitor” Network Tab: – Shows EVERY process with active network connection – Bytes sent/received per process – Which remote addresses each app […]
PC crashing randomly? Reliability Monitor shows exact timeline of crashes, errors, and what caused them. Open: Start → Search “Reliability Monitor” Or: Control Panel → Security and Maintenance → View Reliability History What You See: – Timeline of stability (1-10 score) – Red X = critical events (crashes, failures) – Yellow ! = warnings – […]
Salary negotiation is nerve-wracking without preparation. AI coaches you with specific talking points. The Prompt: Help me prepare for salary negotiation: My role: [Job title] My experience: [X years] Current salary: [$X or N/A if new job] Target salary: [$X] Their offer: [$X if applicable] Location: [City/Remote] Company type: [Startup/Corp/etc] My strengths: [Key skills/achievements] Prepare: […]
Blood test results full of confusing numbers and abbreviations? AI explains what they mean. The Prompt: Explain these medical test results in plain English: [Paste or type your results] For each value: 1. What does this measure? 2. Is my value normal, high, or low? 3. What does abnormal mean for health? 4. What lifestyle […]
Generic workout plans don’t fit your equipment or schedule. AI creates perfectly tailored plan. The Prompt: Create personalized workout plan: My equipment: [gym / home / dumbbells only / no equipment] Goal: [lose weight / build muscle / improve endurance / stay active] Current level: [beginner / intermediate / advanced] Days per week: [3/4/5/6] Time […]
Running all services (database, cache, queue, monitoring) every time is slow. Profiles start only what you need. docker-compose.yml: services: app: build: . ports: – “3000:3000” db: image: postgres profiles: [“dev”, “test”] redis: image: redis profiles: [“dev”] monitoring: image: grafana profiles: [“monitoring”] mailhog: image: mailhog/mailhog profiles: [“dev”] Start Different Profiles: # Just the app (no extras) […]
Rolling updates can accidentally take down too many pods. PDB guarantees minimum availability. Create PDB: apiVersion: policy/v1 kind: PodDisruptionBudget metadata: name: myapp-pdb spec: minAvailable: 2 # Always keep at least 2 pods running selector: matchLabels: app: myapp Or Use maxUnavailable: spec: maxUnavailable: 1 # At most 1 pod can be down at a time selector: […]
Tag pages and author archives can be seen as duplicate content by Google. Noindex them to protect SEO. Add to functions.php: add_action(‘wp_head’, function() { if (is_tag() || is_author() || is_date()) { echo ”; } }); Or Disable Archives Completely: // Redirect tag pages to homepage add_action(‘template_redirect’, function() { if (is_tag()) { wp_redirect(home_url(), 301); exit; } […]
WordPress Heartbeat API pings server every 15-60 seconds causing CPU spikes. Slow it down or disable. Add to functions.php: // Reduce heartbeat frequency add_filter(‘heartbeat_settings’, function($settings) { $settings[‘interval’] = 60; // From 15-60 to 60 seconds return $settings; }); // Disable on frontend only (keep for editor autosave) add_action(‘init’, function() { if (!is_admin()) { wp_deregister_script(‘heartbeat’); } […]
Blurring skin for retouching also removes texture. Frequency Separation edits skin tone and texture on separate layers. Setup: 1. Duplicate layer twice (Ctrl+J twice) 2. Name layers: “Low Frequency” (bottom) and “High Frequency” (top) Low Frequency layer (tone/color): Filter → Blur → Gaussian Blur → 4-6px High Frequency layer (texture/detail): Image → Apply Image: Layer: […]
Manually masking skies takes hours. Sky Replacement uses AI to detect and replace skies automatically. Access: Edit → Sky Replacement Steps: 1. Open photo with boring sky 2. Edit → Sky Replacement 3. Click Sky dropdown → Choose preset or load custom sky 4. AI auto-selects sky and blends colors! Fine-tune Options: – Edge Lighting: […]
Restarting app after every small change wastes minutes. Hot Reload applies changes to running app instantly. Enable Hot Reload: Click the flame icon 🔥 in Debug toolbar (or Alt+F10) Works While: – App is running (with or without debugger) – Even during breakpoints Supports: – Method body changes – Adding new methods – CSS/XAML changes […]