Introduction

HLD represents the best way to build and scale applications to millions of users.

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Tips to Approach the HLD Problem

Step-1: Deciding Requirements

1. Functional Requirements: What should the system do. E.g: Uploading a video
2. Non-Functional Requirements: How well your system performs. E.g: Reliability, Scale, Latency, Massive Traffic.

Step-2: Capcity Estimation

This includes estimating the following:

1. Daily/Monthly Active Users (DAU/MAU)
2. Throughput: requests per second
3. Storage: Gb, Tb
4. Network Bandwidth: Gbps

Step-3: API-Design

Writing Functional Requirements more technicially Look for the Api's/endpoints that are required to support

Step-4: High Level Design

Build a HLD covering the above requirements.

Step-5: Deep Dive

Deep Diving on any aspect the interviewer wants.