The technical interview process at most companies follows a recognisable structure: an initial screening, one or more coding challenges, sometimes a system design round, and a behavioural or culture-fit interview. Each stage tests something different — and each can be specifically prepared for.

Understanding the Technical Interview Format

Before you prepare, know what you're preparing for. Research the company's specific interview process:

  • Check Glassdoor and Leetcode's company-specific interview sections for recent interview reports
  • Ask the recruiter directly: "What does the interview process look like, and are there any areas I should focus my preparation on?"
  • Look at the tech stack mentioned in the job description — this often signals what they'll test

Most technical interviews include some combination of: live coding, take-home exercises, system design, and behavioural questions. Large companies (Google, Meta, Amazon) have highly structured processes; startups tend to be more ad hoc.

Coding Challenges: The Preparation Strategy That Works

The key to coding interview success is deliberate practice — not just solving as many problems as possible, but understanding the underlying patterns that most problems are based on.

Core Topics to Master

  • Data structures: arrays, hash maps, linked lists, trees, graphs, stacks, queues
  • Algorithms: sorting, binary search, BFS/DFS, recursion, dynamic programming
  • Problem patterns: sliding window, two pointers, fast/slow pointers, merge intervals, cyclic sort
  • Complexity analysis: always explain time and space complexity for your solution

Best Practice Resources

  • LeetCode — the industry standard; focus on "medium" difficulty questions, not easy or very hard
  • NeetCode.io — structured roadmap of the most important LeetCode problems by category
  • Blind 75 — the 75 most commonly asked interview questions across FAANG-adjacent companies
  • AlgoExpert — video explanations for common interview problems

How to Approach a Coding Problem in the Interview

  1. Clarify: Before touching any code, ask clarifying questions. What are the constraints? What should happen at edge cases? Can the input be empty?
  2. Think out loud: Verbalise your thinking. Interviewers assess your problem-solving process, not just your answer.
  3. Start with brute force: Get a working solution first, even if it's O(n²). Then optimise.
  4. Test your code: Walk through your code with an example before declaring it done. Catch bugs before the interviewer does.
  5. Discuss complexity: Always close by stating the time and space complexity of your solution.

System Design Interviews

System design interviews test your ability to architect scalable, reliable software systems. They're typically assessed at mid-level and senior engineer roles. The key is to structure your answer with a clear framework rather than jumping to solutions.

A reliable framework:

  1. Clarify requirements and constraints (scale, users, latency targets)
  2. High-level architecture: define the main components and how they interact
  3. Deep dive into key components: databases, caching, APIs, message queues
  4. Address scalability, reliability, and failure handling
  5. Identify trade-offs in your design

Recommended preparation: the book "Designing Data-Intensive Applications" by Martin Kleppmann, and system design walkthroughs on YouTube channels like ByteByteGo.

Behavioural Questions: The STAR Method

Most technical roles also include a behavioural round. These questions ("Tell me about a time you…") are assessed using structured frameworks at many companies, particularly Amazon (which uses its Leadership Principles) and Google.

The STAR method remains the gold standard:

  • Situation — set the context (1 sentence)
  • Task — what was your specific responsibility
  • Action — what you did, with specifics about your contribution
  • Result — the measurable outcome

Prepare 5–7 strong STAR stories from your experience that can be adapted to different questions. Topics that frequently come up: dealing with conflict, handling failure, prioritising under pressure, technical disagreements, mentoring others, going above and beyond.

Day-Of Tips: Managing Nerves and Performing Your Best

  • Sleep is your greatest asset — don't cram the night before. A well-rested brain outperforms an exhausted one every time.
  • Arrive (or log in) early — give yourself buffer time so you're not rushing
  • It's okay to pause — silence while you think is professional, not embarrassing
  • Ask for hints — if you're stuck, say "I'm thinking about this direction, does that seem reasonable?" Interviewers often prefer guiding you to watching you struggle in silence
  • Wrong answers aren't automatic failures — how you handle uncertainty and think through problems matters as much as getting the right answer
"The best interview candidates aren't the ones who know everything — they're the ones who approach unknown problems systematically and communicate clearly while doing it."