Recommendations for preparing for an interview (short term)

Do you have an interview in a week or two? Don't panic. This chapter is a condensed preparation tactic, based on the Pareto principle: 20% of efforts that give 80% of the results. There's no time here for deep study of theory - only practical actions.

Important Warning

Short-term training works if you already have basic development experience. If you are completely new to the backend, honestly ask for more time or reschedule the interview.

Why short-term training works

Limited set of themes

The same set of components appears regularly in System Design interviews: Load Balancers, Caches, Queues, databases. They can be mastered in 1-2 days.

Repeating patterns

Most systems use similar architectural solutions. Having analyzed 3-5 classic cases, you will cover 80% of the questions.

Framework is more important than knowledge

Interviewers evaluate structure of thinking, not encyclopedic knowledge. A good framework compensates for gaps in theory.

Communication is king

The ability to explain your decisions and discuss trade-offs is often more important technical depth. This can be worked out quickly.

High-Yield topics: what to learn first

These components appear in almost every System Design interview. Make sure you understand each of them at the "why is it needed and when to use it" level.

Load Balancers

Round-robin, least connections, health checks

Caching

Redis, Memcached, CDN, cache invalidation

Message Queues

Kafka, RabbitMQ, async processing

SQL Databases

ACID, indexes, joins, replication

NoSQL Databases

Document, Key-Value, Wide-column, Graph

API Gateway

Rate limiting, auth, routing

CDN

Edge caching, geo-distribution

Data Partitioning

Sharding, consistent hashing

CAP Theorem

Consistency vs Availability trade-offs

6-step express framework

Learn this algorithm by heart. It will save you when your head is empty from stress.

Clarification of requirements

5 min

Ask 3-5 key questions. What's in scope? How many users? What are the SLAs?

Scale assessment

3 min

Back-of-envelope: QPS, storage, bandwidth. Orders of magnitude are sufficient.

High-Level Design

10 min

Draw the main components and their connections. Agree with the interviewer!

Deep Dive

15 min

Dig deeper into 1-2 critical components. Show your expertise.

Trade-offs

5 min

Discuss the alternatives and why you chose this solution.

Scaling

7 min

How will the system grow? Where are the bottlenecks? How to eliminate them?

7 day plan

If you have a week, here is the optimal time allocation. Every day requires 2-4 hours of concentrated work.

Day 1: Orientation and framework

Watch 2-3 mock interviews from the third part
Learn the 6-step framework by heart
Write down the evaluation criteria: structure, trade-offs, communication

Day 2: Basic Components

Repeat high-yield themes (see list above)
For each component: when to use, trade-offs, examples
Make a one page cheat sheet

3-4

Days 3-4: Analysis of classical systems

Disassemble 2 systems per day. For each, draw a diagram and say the solution out loud.

Day 3

Day 4

Day 5: Practice with timer

Take 2-3 new tasks (Rate Limiter, Notification System)
Solve each one in 45 minutes with a timer
Record yourself on video or audio

Day 6: Full mock

Conduct a 60-minute mock interview with a partner
Use a fresh task (Uber, Ticketmaster)
Get detailed feedback: structure, time, depth

Day 7: Final preparation

Repeat cheat sheet and framework
Work on weak points from the mock interview
Relax in the evening - a fresh head is more important than cramming

Where to find mock interviewers

A mock interview is the most effective way to prepare. Here are proven platforms and approaches:

Pramp

For free

Platform for mutual mock interviews. You interview your partner, he interviews you. A great way to see the process from both sides.

pramp.com

Exponent

Paid

Mocks with FAANG engineers. Large database of video analyzes and courses. Expensive, but high quality.

tryexponent.com

Educative.io

Paid (subscription)

Grokking System Design course + mock interview tool with automated feedback.

educative.io

YouTube channels

For free

Exponent, Gaurav Sen, System Design Interview - watch others undergo interviews and learn from their mistakes.

YouTube

Alternative options

Work colleagues — ask a senior developer to mock
Telegram/Discord communities — look for partners for mutual mocks
Record yourself on video - solve the problem out loud and analyze the recording
Rubber duck debugging - explain the decision to an imaginary interlocutor