Search

Lessons (40)

• Extending Kubernetes: CRDs, Operators and Admission

  Teach Kubernetes new resource types, automate them with controllers, and enforce policy before objects are saved. Kubernetes is …

• NestJS Core Concepts

  … That boundary is what keeps a large Nest app from becoming a tangle. Controllers and services ts @Controller …

• Resources, QoS and Scheduling Control

  How the scheduler decides where pods run, and how requests, limits, affinity, taints and disruption budgets shape it …

• MVC, MVP & MVVM

  … Model–View–Controller Invented at Xerox PARC in 1979 for Smalltalk. The most famous of the three. mermaid …

• Kubernetes Cluster Architecture, Simply

  … the control plane and worker nodes](/img/kubernetes/architecture.svg) Part Simple job --- --- Control plane Receives requests, remembers …

• Premiere-Night Video Streaming

  Let millions press Play together by separating small control-plane APIs from CDN-delivered video bytes. The problem …

• Multi-Account Strategy, Governance and Security Operations

  Organize accounts with Organizations and Control Tower, enforce guardrails with SCPs, and detect threats with CloudTrail, Config and …

• Internals, Upgrades, Resilience and Interview Questions

  Know what happens inside the control plane, how to upgrade and back up safely, and answer common senior …

• Layered (N-Tier) Architecture

  … No SQL in controllers; no HTTP in services. 2. Dependencies point down: a layer may use the layer …

• Containers at Scale: ECS Deep Dive and EKS

  … patterns for each. ECS or EKS? ECS EKS --- --- --- Control plane AWS-native, no extra fee Managed Kubernetes, hourly …

• Brokers, Replication & Durability

  … Keep it false for important topics.) The controller and KRaft One broker acts as the controller : it tracks …

• Embeddings, Semantic Search, and RAG

  … 4. Retrieve: search with the user query, apply access controls, and select relevant passages. 5. Generate: tell the …

• Clean Architecture in Depth

  … one class per user action The application's behaviour changes Entities + port interfaces 🔵 Interface adapters Controllers, presenters, gateways …

• Design System Operations

  … This is useful for complex controls such as menus and dialogs, where keyboard navigation and focus management are …

• Services and Ingress: Let Traffic Find Your App

  … Your cluster also needs an Ingress controller (for example NGINX, Traefik, or a cloud controller) that reads these …

• Structural Patterns: How to Connect Objects

  … Same doorway, but the guard checks your badge, logs your visit, or says "come back later". Problem: control …

• Practical Lab: S3 File Upload and CloudFront Delivery with NestJS

  Build a private S3 bucket, put CloudFront in front of it with Origin Access Control, create a least …

• Resilience, Disaster Recovery and Multi-Region Design

  … For control of failover decisions during major events, use Application Recovery Controller routing controls. mermaid flowchart TD U …

• How a Web Request Works

  … application/json Cache-Control: max-age=60 { "id": 42, "name": "Keyboard", "price": 49.99 } HTTP methods Method Meaning …

• IAM Deep Dive: Policy Evaluation, STS and Cross-Account Access

  … See [IAM policy attachment controls](https://docs.aws.amazon.com/IAM/latest/UserGuide/access controlling.html). Finding and …

• Hexagonal Architecture (Ports & Adapters)

  … HDMI for a screen, USB for controllers, a network port. The console doesn't care whether you plug …

• Putting AI Systems into Production

  Design dependable model integrations with fallbacks, observability, versioning, cost controls, and human review. The big idea A production …

• CloudFront: Faster Websites and Safer File Delivery

  … Use Origin Access Control so CloudFront can read the bucket but the public internet cannot. 4. Add an …

• Safe AWS Deployments with IaC and CI/CD

  Keep infrastructure in version control, review changes before applying them, and deploy applications through repeatable automated steps. Two …

• AI Evaluation, Safety, and Security

  … Abuse and misuse: apply authentication, rate limits, content controls appropriate to the use case, and escalation paths for …

• C4 Architecture Diagrams: Context, Container, Component and Code

  … The web application sends POST /checkout to the controller. 2. The controller turns the HTTP request into a …

• Design a Logging and Monitoring Platform

  … Preserve tenant isolation, retention controls and an audit trail. Measure ingestion lag, dropped samples, query latency, cardinality and …

• Practical Project: Deploy a Real CRM App on EKS

  … Worker nodes and scheduling The EKS control plane does not run your pods. A node group needs running …

• Onion Architecture & Clean vs Hexagonal vs Onion

  … infrastructure, UI, tests Implementations of the interfaces, web framework, DB, external APIs SqlOrderRepository , controllers, EF Core / Prisma mermaid …

• Multi-Region and Disaster Recovery

  … Payment and final order state Stronger replication or controlled failover; reconcile uncertain payments. Restaurant menus Serve regional cache …

• Flash Sale: 10 Million Buyers, No Oversell

  … Admission controls pressure but grants no inventory ownership. 2. Create a reservation using a conditional stock update and …

• Frontend Security

  … Access-Control-Allow-Origin: https://app.shop.com<br/ Access-Control-Allow-Credentials: true App- API: GET /orders …

• RBAC and Cluster Security

  Control who can do what with RBAC, harden pods with security contexts and Pod Security Standards, and protect …

• Cluster Networking, DNS and NetworkPolicies

  … Ingress is simple but limited and relies on controller-specific annotations. The Gateway API is its modern successor …

• Kubernetes: Start Here

  … the cluster, its servers, and the control plane.

• React Hooks in Practice

  … controller.signal }) .then((r) = r.json()) .then(setUser) .catch((e) = { if (e.name !== "AbortError") console.error(e); }); return …

• Views, Triggers & Stored Procedures

  … Transaction-control and return-value capabilities vary by engine, so name the product in an interview.

• Which Pattern Do I Need?

  … Proxy controls access to the same behaviour. Adapter vs Facade Adapter makes one interface fit another. Facade simplifies …

• Async JavaScript: Promises, async/await and Node's Event Loop

  … when the HTTP client disconnects const controller = new AbortController(); req.on("close", () = controller.abort()); await db.query(sql …

• SQL Language, Identifiers & Data Types

  … Many systems call COMMIT and ROLLBACK transaction-control statements. Q7: Identity, sequence and UUID An identity/auto-increment …