# security

Deep DiveDatabase Engineering Mastery

DatabasesAdvanced

Negative Result Caching: Protecting Databases

Negative Result Caching Mental Model > The source of truth where data persistence, consistency, and retrieval speed must be balanced. If a user searches for a non-existent ID, don't let that query hit your main database…

Apr 20, 20267 min read

#databases#java#performance

Multi-Tenancy in NoSQL: Data Isolation Strategies for SaaS

Case Study: Design a Multi-Tenant SaaS System Mental Model > Connecting isolated components into a resilient, scalable, and observable distributed web. Designing a SaaS platform like Slack or Shopify requires choosing a…

Apr 20, 20265 min read

#databases#security#system-design

Stateless Auth: Managing JWT Blacklisting at Scale

Stateless Auth: JWT Revocation Mental Model > Connecting isolated components into a resilient, scalable, and observable distributed web. JWTs are often marketed as "stateless authentication", but the first real security…

Apr 20, 20267 min read

System Design: Designing a Global Distributed Rate Limiter

Case Study: Design a Rate Limiter (Token Bucket / Leaky Bucket) Mental Model > Connecting isolated components into a resilient, scalable, and observable distributed web. Rate limiting is a critical component for protecti…

Apr 20, 20263 min read

#databases#security#system-design

Case StudyBackend Systems Mastery

System Design: Designing a Global Payment Gateway (Stripe Scale)

System Design Masterclass: Designing a Payment Gateway (Stripe) Mental Model > Connecting isolated components into a resilient, scalable, and observable distributed web. Designing a system to serve photos or short URLs i…

Apr 20, 20267 min read

System Design: Building a Session Management Platform

Sessions feel simple until they become a security boundary. A user logs in. The system gives them a token or cookie. Requests work. End of story. Then reality arrives: - one user is logged in on five devices - an access…

Apr 18, 202612 min read

Deep DiveAI Infrastructure Mastery

AI/MLAdvanced

MCP for Backend Engineers: Tools, Agents, and Production Guardrails

MCP, the Model Context Protocol, is useful because it gives AI applications a standard way to connect to tools and context. For backend engineers, the interesting part is not the hype around agents. The interesting part…

Apr 8, 202614 min read

#ai-ml#security#system-design

System Design: Building an API Gateway Platform

Case Study: Design an API Gateway Mental Model > Connecting isolated components into a resilient, scalable, and observable distributed web. An API Gateway is the single entry point for all clients. It handles cross-cutti…

Apr 8, 20263 min read

#devops#security#system-design

System Design: Building an Authorization Service

Security Basics (Auth, Encryption) Mental Model > Connecting isolated components into a resilient, scalable, and observable distributed web. Security in a distributed system is built on two pillars: Authentication (AuthN…

Apr 8, 20263 min read

System Design: Building a File Upload Platform

File upload looks easy until production traffic arrives. Users upload huge files, mobile networks drop halfway through, browsers retry, malicious files appear, thumbnails fail, metadata gets out of sync, signed URLs expi…

Apr 8, 202611 min read

#ai-ml#aws#security

System Design: Building a Secrets Management Platform

Secrets management looks like a simple storage problem until you operate it in production. At first, the requirement sounds like this: "Store API keys and database passwords somewhere safe." Then real systems arrive. Ser…

Apr 8, 202615 min read

#devops#security#system-design

System Design: Building an Audit Log System for Compliance and Debugging

Audit logs answer a simple question: who did what, to which resource, from where, and when? That question matters during security investigations, customer support, compliance audits, data recovery, and debugging. A norma…

Apr 7, 20266 min read