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Lessons (29)

• Creational Patterns: How to Make Objects

  … every object links to a prototype ( Object.create(proto) ). That's this pattern built into the language. Use …

• Domain-Driven Design: Tactical Patterns

  … Lisbon<br/ (still the same customer)"] end subgraph Value["💶 Value object: only values matter"] V1["€10.00"] --- V2 …

• Structural Patterns: How to Connect Objects

  … inventory, payment, shipping, email… class CheckoutFacade { constructor({ inventory, payments, shipping, mailer }) { Object.assign(this, { inventory, payments, shipping, mailer …

• TypeScript Essentials

  … those API response Record<string, number Object with those key/value types Lookup tables ReturnType<typeof fn What …

• Behavioral Patterns I: Observer, Strategy, Command, State

  … The channel doesn't know or care who you are. Problem: when one object changes, many others need …

• What Are Design Patterns?

  … create objects? Factory Method, Abstract Factory, Builder, Prototype, Singleton 🧱 Structural How do I connect objects into bigger …

• Code Smells & Refactoring

  … zip} ${this.city} ; } } // order.customer.mailingLabel() Primitive obsession → Value Object js // ❌ Money as a plain number: which currency …

• Onion Architecture & Clean vs Hexagonal vs Onion

  … inside → out) Contains Example --- --- --- 🟡 Domain model Entities, value objects, business rules Order , Money , Email 🟠 Domain services …

• Hash Maps & Sets

  … unique values only const seen = new Set([1, 2, 2, 3]); seen.has(2); // true seen.size; // 3 …

• Behavioral Patterns II: Chain, Template, Iterator, Mediator, Memento, Visitor

  … object types without changing those types . js // Node types (rarely change) const num = (value) = ({ type: "num", value }); const …

• ConfigMaps, Secrets & Storage

  … LOG LEVEL valueFrom: configMapKeyRef: { name: shop-api-config, key: LOG LEVEL } a single key volumeMounts: - name: settings mountPath …

• Clean Architecture

  … your business rules (the valuable part) depend only on simple interfaces. The database, web framework and email provider …

• Deployments, ReplicaSets & Rollouts

  … how objects find each other Labels are key/value tags on objects. Selectors pick objects by label. This …

• React Hooks in Practice

  … 1 }; useEffect(() = { fetchData(options).then(setData); }, [options]); // new object every render! // ✅ Depend on primitive values useEffect(() = { fetchData({ page …

• Clean Error Handling

  … or a result object const age = Number(text); return Number.isInteger(age) ? { ok: true, value: age } : { ok: false …

• Why Kubernetes?

  … P3 CM["⚙️ ConfigMap / 🔐 Secret"] -.config.- P1 & P2 & P3 Object One-line meaning Lesson --- --- --- Pod The smallest unit: one …

• Heaps & Priority Queues

  … No node objects needed: For the node at index i Formula --- --- Parent Math.floor((i - 1) / 2) Left …

• Kubernetes Cluster Architecture

  … Validates and stores objects Head office reception etcd A distributed key-value database holding the entire cluster state …

• Serverless Architecture

  … s3.getObject(record.s3.bucket.name, record.s3.object.key); const thumbnail = await sharp(image).resize(200).webp …

• Trees & Binary Search Trees

  … node.right; } return null; } function insert(node, value) { if (!node) return new TreeNode(value); if (value < node.value …

• Clean Architecture in Depth

  … Promise<void { await this.pool.query( "INSERT INTO orders (id, customer id, total cents, status) VALUES ($1, $2 …

• React Fundamentals

  … a new value. jsx // ❌ React won't notice cart.items.push(product); setCart(cart); // ✅ New object and new …

• DRY: Don't Repeat Yourself

  … client Generate types from OpenAPI / GraphQL schema Config values copied between files One .env / config module The same …

• SQL vs NoSQL Databases

  … four families mermaid mindmap root((NoSQL)) Document MongoDB Firestore JSON documents Key-value Redis DynamoDB get / set by …

• How Browsers Render a Page

  … HTML → DOM The browser reads HTML top to bottom and builds the Document Object Model , a tree of …

• Sorting Algorithms

  … But if values are small integers in a known range (ages, exam scores 0–100), you can just …

• Caching & Redis

  … avoids race conditions } 💡 Prefer deleting the key over writing the new value into it. Two concurrent updates can …

• JavaScript Essentials: Event Loop, Closures & this

  … setCount((c) = c + 1) uses the latest value } Part 3: this this is decided by how a function …

• Domain-Driven Design: Strategic Design

  … Subdomains, ubiquitous language, bounded contexts, context maps Entities, value objects, aggregates, repositories, domain events Answers Where do we …