Technical interviews follow patterns. Once you understand the structure, you can prepare systematically instead of hoping for the best. Here's what I've learned from both sides of the interview table.
Know the Structure
Most technical interviews have four stages. Knowing what's coming lets you prepare for each:
- Phone screen -- Quick validation of your background and technical basics
- Coding challenge -- Live or take-home exercise testing problem-solving skills
- System design -- Architecture discussion for mid-to-senior roles
- Behavioral -- Culture fit and communication assessment
Research your target company's specific process on Glassdoor or Blind before you start preparing.
Coding Challenges: Focus on Process, Not Perfection
Interviewers care more about your thinking process than getting the optimal solution on the first try.
The approach that works:
- Clarify the problem -- Ask questions before writing code. Confirm inputs, outputs, edge cases, and constraints. This shows thoughtfulness.
- Start with a working solution -- A correct brute-force solution beats an incomplete optimized one. Get something working first.
- Talk through your thinking -- Narrate as you go. "I'm checking for edge cases here because..." gives the interviewer insight into your reasoning.
- Then optimize -- Once your solution works, discuss time/space complexity and improve it.
- Test with edge cases -- Empty inputs, single elements, very large inputs, null values. The candidates who test their own code stand out.
Don't panic if you get stuck. Pause, explain what you're thinking, and try a different approach. Interviewers value composure and problem-solving over speed.
System Design: Think in Trade-offs
System design interviews test whether you can reason about architecture at scale. The key: there's no single right answer. It's about demonstrating your thought process.
Framework:
- Start with requirements -- What are we building? What scale? What constraints?
- Draw the big picture -- Core components, how they connect, data flow
- Identify bottlenecks -- Where will this system break under load?
- Discuss trade-offs -- Every decision has costs. "I chose a SQL database here because of strong consistency requirements, but NoSQL would give us better write throughput if we relaxed that constraint."
- Scale up -- How does the design change at 10x or 100x load? Caching, sharding, CDNs, message queues.
Practice by designing systems you use daily: a URL shortener, a chat application, a notification service.
Behavioral Interviews: Use the STAR Method
Structure your answers with STAR to keep them focused and impactful:
- Situation -- Set the context briefly
- Task -- What was your specific responsibility?
- Action -- What did you actually do? (This is the meat of your answer)
- Result -- What happened? Quantify if possible.
Example: "Our production database hit capacity limits during peak traffic (Situation). I was responsible for ensuring zero-downtime during the migration to a larger instance (Task). I implemented a blue-green deployment strategy with read replicas to handle traffic during the switchover (Action). We completed the migration with zero downtime and reduced query latency by 40% (Result)."
Prepare 5-6 stories that cover: teamwork, conflict resolution, a technical failure you recovered from, a time you led an initiative, and a time you had to make a quick decision under pressure.
After the Interview
Send a follow-up email within 24 hours. Keep it short: thank them, reference something specific you discussed, and reiterate your interest. This small step puts you ahead of most candidates.
Recommended Prep Tools
- LeetCode -- Algorithm practice. Start with easy problems, build up.
- System Design Primer -- The best free GitHub resource for system design prep
- Pramp -- Free mock interviews with peers
- Glassdoor / Blind -- Research real interview questions from your target company
Preparing for a cloud/DevOps interview specifically? Reach out -- I'm happy to share role-specific advice.