How to Prepare for Technical Interviews

Step 1: Understand the Interview Format

Most tech interviews have three types of rounds:

| Round | What they test | Duration | | ----------------- | ------------------------------------------------- | --------- | | Coding | Problem-solving with data structures & algorithms | 45-60 min | | System Design | Architecture and scalability thinking | 45-60 min | | Behavioral | Communication, teamwork, conflict resolution | 30-45 min |

Entry-level roles focus heavily on coding. Senior roles add system design. All levels include behavioral questions.

The key insight: interviews test your thought process, not just your answer. Talking through your approach matters as much as getting it right.

Step 2: Data Structures You Must Know

You don't need to know every data structure — but you need these cold:

Arrays & Strings:

Hash Maps — O(1) lookup, the most useful interview tool:

Stacks & Queues:

Step 3: The UMPIRE Method for Coding Problems

Use this framework for every coding problem:

1. Understand — Restate the problem. Ask clarifying questions.
2. Match — Identify the pattern (sliding window? BFS? two pointers?)
3. Plan — Write pseudocode before real code
4. Implement — Write clean, readable code
5. Review — Walk through with a test case
6. Evaluate — Analyze time and space complexity

Example walkthrough:

"Given a string, find the length of the longest substring without repeating characters."

1. Understand: "So if input is 'abcabcbb', output is 3 because 'abc' is the longest unique substring?"
2. Match: Sliding window pattern — expand right, shrink left when duplicate found
3. Plan: Use a Set to track chars in window, two pointers for window bounds
4. Implement: Write the code
5. Review: Trace through "abcabcbb" step by step
6. Evaluate: O(n) time, O(min(n, alphabet)) space

Step 4: System Design Basics

System design questions test your ability to think at scale:

"Design a URL shortener like bit.ly"

Framework:

1. Requirements — What features? How many users? Read-heavy or write-heavy?
2. High-level design — Draw the main components (load balancer, API server, database, cache)
3. Deep dive — Pick a component and detail it (how do you generate unique short codes? How do you handle collisions?)
4. Trade-offs — SQL vs. NoSQL? Consistency vs. availability?

Key concepts to know:

• Load balancing — Distribute traffic across servers
• Caching — Store frequently accessed data in memory (Redis)
• Database sharding — Split data across multiple databases
• CDN — Serve static content from edge locations
• Message queues — Decouple services for async processing

Step 5: Behavioral Questions (STAR Method)

Behavioral questions assess soft skills. Use the STAR method:

• Situation — Set the context
• Task — What was your responsibility?
• Action — What did you specifically do?
• Result — What was the outcome? (Use numbers if possible)

Common questions and how to prepare:

| Question | What they're testing | | ---------------------------------------------------- | ----------------------------- | | "Tell me about a time you disagreed with a teammate" | Conflict resolution | | "Describe a project you're proud of" | Passion, technical depth | | "Tell me about a time you failed" | Self-awareness, growth | | "How do you handle tight deadlines?" | Prioritization, communication |

Pro tip: Prepare 5-6 stories that cover different themes. Each story can answer multiple questions by emphasizing different aspects.

Step 6: Practice Strategy

Week 1-2: Foundations

• Review arrays, strings, hash maps, trees, graphs
• Solve 2-3 easy problems per day
• Focus on understanding patterns, not memorizing solutions

Week 3-4: Pattern Recognition

• Study these patterns: sliding window, two pointers, BFS/DFS, dynamic programming, binary search
• Solve 1-2 medium problems per day
• Time yourself (45 minutes per problem)

Week 5-6: Mock Interviews

• Practice with a friend or use platforms like Pramp
• Record yourself explaining solutions
• Practice system design out loud with a whiteboard

Daily habits:

• Solve at least one problem every day (consistency beats cramming)
• After solving, read the discussion for alternative approaches
• If you can't solve a problem in 30 minutes, read the solution, then re-solve it from memory the next day

Step 7: Interview Day Tips

Before the interview:

• Test your setup (camera, mic, screen sharing, IDE)
• Have a glass of water nearby
• Review your notes on common patterns

During the interview:

• Think out loud — silence is worse than wrong guesses
• Ask clarifying questions before coding
• Start with the brute force approach, then optimize
• Write clean code with meaningful variable names
• Test your solution with examples, including edge cases
• If stuck, say "I'm thinking about X approach because Y"

Questions to ask your interviewer:

• "What does a typical day look like on this team?"
• "What's the biggest technical challenge you're facing?"
• "How does the team handle code reviews?"
• "What does the onboarding process look like?"

What's next? Learn How to Read Documentation Effectively — a skill that separates self-sufficient engineers from those who are always asking for help.