Complete Guide to Preparing for SDE-1 Role in 90 Days

For a deeper dive into these skills, consider enrolling in our Data Structures and Algorithms course or Master DSA, Web Dev, System Design course.

90-Day Preparation Plan

Preparing for an SDE-1 role in 90 days requires a disciplined, phased approach. We’ve divided the plan into three 30-day phases: Foundation, Intermediate, and Advanced.

Phase 1: Foundation (Days 1-30)

This phase focuses on building a strong base in programming and basic DSA concepts.

• Weeks 1-2: Master a Programming Language
  • Choose one language (e.g., Python, Java, or C++) and master its syntax, data types, control structures, functions, and object-oriented programming.
  • Practice writing simple programs to solidify your understanding.
  • Resource: Web Development course for foundational programming skills.
• Weeks 3-4: Learn Basic Data Structures
  • Study arrays, strings, linked lists, stacks, and queues. Understand their operations (e.g., push/pop for stacks, enqueue/dequeue for queues).
  • Implement these structures from scratch to grasp their mechanics.
  • Resource: Introduction to Algorithms by Cormen or online tutorials.
• Week 5: Basic Algorithms
  • Learn sorting algorithms (bubble sort, merge sort, quicksort) and searching algorithms (linear search, binary search).
  • Understand recursion and its applications.
  • Practice 10-15 easy problems on platforms like LeetCode or HackerRank.
• Week 6: Introduction to OS and DBMS
  • Study basic operating system concepts (processes, threads, memory management).
  • Learn SQL basics (SELECT, INSERT, JOIN) and NoSQL concepts.
  • Resource: Data Science course for database fundamentals.

Phase 2: Intermediate (Days 31-60)

This phase builds on your foundation, diving deeper into DSA and introducing system design.

• Weeks 7-8: Advanced Data Structures
  • Study trees (binary trees, binary search trees) and graphs (representation, BFS, DFS).
  • Implement tree traversals (inorder, preorder, postorder) and graph algorithms.
  • Practice 20-30 medium-level problems on LeetCode.
• Weeks 9-10: Advanced Algorithms
  • Learn dynamic programming (e.g., knapsack, longest common subsequence), greedy algorithms, and graph algorithms (shortest paths, minimum spanning tree).
  • Analyze time and space complexity for each solution.
  • Resource: Crash course for quick algorithm refreshers.
• Week 11: System Design Fundamentals
  • Understand scalability, reliability, and trade-offs in system design.
  • Study basic components like load balancers, caching, and databases.
  • Resource: Designing Data-Intensive Applications by Martin Kleppmann.
• Week 12: Behavioral Interview Preparation
  • Research company-specific leadership principles (e.g., Amazon’s 16 Leadership Principles).
  • Practice answering questions like “Tell me about a time you faced a challenge.”
  • Use the STAR method (Situation, Task, Action, Result) for structured responses.

Phase 3: Advanced (Days 61-90)

This phase focuses on mastering advanced topics and preparing for interviews.

• Weeks 13-14: Advanced DSA
  • Master advanced tree and graph algorithms (e.g., AVL trees, Dijkstra’s algorithm).
  • Study dynamic programming optimizations and advanced graph problems.
  • Practice 20-30 hard problems on LeetCode or HackerRank.
• Weeks 15-16: System Design Deep Dive
  • Learn about distributed systems, caching strategies, and load balancing.
  • Practice designing systems like a URL shortener or a messaging app.
  • Resource: Master DSA, Web Dev, System Design course.
• Week 17: Mock Interviews
  • Conduct mock technical and behavioral interviews with peers or mentors.
  • Use platforms like Pramp or Interviewing.io for realistic practice.
• Weeks 18-20: Review and Polish
  • Review weak areas and revisit challenging problems.
  • Take full-length practice tests to simulate interview conditions.
  • Network on LinkedIn to seek referrals, which can boost your application’s visibility.

Common SDE-1 Interview Questions

SDE-1 interviews typically include coding, system design, and behavioral questions. Below are 30 common questions, categorized by topic, with brief solution approaches. These questions are drawn from real candidate experiences shared on platforms like Glassdoor, AmbitionBox, and GeeksforGeeks.

Arrays and Strings

1. Two Sum
   • Problem: Given an array of integers and a target sum, find two numbers that add up to the target.
   • Approach: Use a hash map to store numbers and their indices. For each number, check if target – num exists in the map. Time complexity: O(n).
2. Longest Substring Without Repeating Characters
   • Problem: Find the length of the longest substring without repeating characters.
   • Approach: Use a sliding window with a hash set to track characters. Time complexity: O(n).
3. Group Anagrams
   • Problem: Group a list of strings into anagrams.
   • Approach: Use a hash map with sorted strings as keys to group anagrams. Time complexity: O(n * k * log k), where k is the maximum string length.
4. Reverse a String
   • Problem: Reverse a given string.
   • Approach: Use two pointers to swap characters from start and end. Time complexity: O(n).

5. Palindrome Check

• • • Problem: Check if a string is a palindrome.
    • Approach: Compare characters from start and end using two pointers. Time complexity: O(n).