Technical interviews reward steady preparation more than last-minute cramming. If you have an interview coming up in a month, or you are starting your job search and want to be ready, a structured plan helps you cover the right topics without burning out.
This 30-day plan assumes about two to three hours a day. It is written for software roles, but the same approach works for testing, data and DevOps positions: replace the "core stack" topics with the skills your target roles ask for.
Before you start: know what you are preparing for
Spend an hour reading five to ten job descriptions for roles you want. Write down:
- The programming language most of them ask for.
- The frameworks, databases and tools that appear repeatedly.
- The type of company. Product companies usually test data structures and algorithms heavily. Service companies often focus on fundamentals, aptitude and communication. Startups tend to ask practical questions about the stack they use.
This list decides how you split your time. There is no point mastering dynamic programming if every role you are applying for asks about SQL and REST APIs.
Week 1: fundamentals
Most interviews, including those for experienced candidates, open with basics. Weak fundamentals are one of the most common reasons strong candidates are rejected.
- Days 1 to 2: your main language. Data types, control flow, functions, error handling, and the language-specific questions that come up again and again (for Java: OOP, collections, equals and hashCode; for Python: lists versus tuples, mutability, decorators; for JavaScript: closures, promises and the event loop).
- Days 3 to 4: object-oriented programming. Encapsulation, inheritance, polymorphism and abstraction, explained with your own examples, not textbook ones.
- Day 5: databases and SQL. Joins, GROUP BY with HAVING, subqueries, indexes, normalisation and the difference between primary and foreign keys. Practise writing queries by hand.
- Day 6: computer science basics. Processes versus threads, how HTTP works, what happens when you type a URL into a browser, and basic networking terms.
- Day 7: review. Go back over anything that felt shaky and write short notes you can revise later.
Week 2: data structures and problem solving
Coding rounds test whether you can break down a problem and write working code under some time pressure. Focus on patterns rather than memorising solutions.
- Days 8 to 9: arrays and strings, including two pointers and sliding window problems.
- Day 10: hash maps and sets, for counting, lookups and finding duplicates.
- Day 11: stacks, queues and linked lists.
- Day 12: recursion, binary search and sorting.
- Day 13: trees and basic graph traversal (BFS and DFS).
- Day 14: a timed practice session. Solve three problems in 90 minutes without looking at hints.
For each problem, practise speaking your approach out loud before you code. In a real interview, explaining your thinking matters almost as much as the final answer. If you get stuck in an interview, saying "my first idea is a brute-force approach in O(n²); let me see if a hash map can bring it down" is far better than silence.
Week 3: your core stack and your projects
This week is about depth in what you will actually use on the job.
- Days 15 to 18: your framework or main tools. If you are a backend developer, that might be Spring Boot or Laravel: request lifecycle, dependency injection, ORM, authentication and building a REST API. For frontend: component state, rendering, routing and API calls. Build or extend a small project, because practical rounds often ask you to code a feature live.
- Days 19 to 20: your own projects. Interviewers will ask about everything on your resume. For each project, prepare answers to: why you built it, how it is structured, the hardest problem you solved, what you would do differently, and how it would handle ten times more users.
- Day 21: basic system design. Even freshers may be asked how they would design something simple, like a URL shortener or a library system. Learn the vocabulary: client and server, database choice, caching, load balancing and APIs.
Week 4: mock interviews and HR preparation
- Days 22 to 24: mock technical interviews. Practise with a friend, a senior or a mock interview platform. Ask them to interrupt you with follow-up questions, as real interviewers do.
- Day 25: behavioural questions. Prepare stories for a time you solved a difficult problem, worked in a team, handled a conflict and made a mistake. Use a simple structure: the situation, what you did, and the result.
- Day 26: your introduction. Prepare a 60 to 90 second answer to "Tell me about yourself". Our guide to answering it includes sample answers.
- Day 27: company research. Learn what the company builds, who its customers are and any recent news. Prepare two thoughtful questions to ask at the end of the interview.
- Days 28 to 29: revision. Go through your notes and redo the problems you found hardest.
- Day 30: rest. Check your interview time, the link or venue and your documents, then stop studying early and sleep well.
On the day of the interview
- For online interviews, test your camera, microphone and internet connection 15 minutes early, and keep a phone hotspot ready as a backup.
- Keep a copy of your resume and a pen and paper nearby.
- When you get a coding problem, repeat it back, ask about edge cases and input sizes, describe your approach, then write the code.
- If you do not know an answer, say so honestly and explain how you would find out. Interviewers respect that far more than a confident guess that turns out wrong.
If you have less than 30 days
Compress the plan, but keep the order: fundamentals first, then your projects and core stack, then problem solving. Fundamentals and your own projects come up in almost every interview, while advanced algorithms only matter for some companies. With one week, spend two days on fundamentals, two on your projects and stack, two on practice problems, and one on mock interviews and your introduction.
Every job listing on JOB_SPOT_360 includes the typical selection rounds and likely questions for that role, so you can tailor this plan to a specific opening.