Tracks · SDE-1, SDE-2, Senior

Interview craft

A good answer is not enough if you cannot say it clearly in the time you have. This track covers the parts of an interview that are about how you speak. You learn how the second half of a design round goes and how each level sounds. You build a bank of real stories, defend every line of your resume, and run a coding round out loud. You practise with AI mock interviews on the way.

Start step 1

13steps in 3 stages
5 h 35 minin total
2 weeksat 4 hours a week

Start here if you lose points on how you explain your work, even when your answer is right.

Skip this track if you are still learning the basics. Do the SDE-1 track first.

The track has 9 lessons, 0 trade-offs, 4 practice steps. Steps marked “Free account” are inside the app.

Stage 1 of 3 · 1 h 57 min

Run a design round well

You can handle a twist in the second half, show your level, plan your practice and defend a full design.

Lesson
The second half of the round: twists and deep dives
How to handle a sudden change in the problem, how to choose two deep dives, and how to spend the last 18 minutes of a 45-minute round.
24 min
Lesson
What SDE-1, SDE-2 and SDE-3 answers look like
The same interview question answered at three levels, side by side, so you can see what an SDE-1, an SDE-2 and an SDE-3 answer each contain.
12 min
Lesson
How to practise: plans and mock interviews
A weekly practice plan with real minutes, how to run a mock interview under the clock, and a short self-review that turns each mistake into a rule.
12 min
Lesson
Capstone: design and defend a system end to end
One full design round for a food-ordering app: the six steps, then three changes from the interviewer, each defended with one table of load against limit.
24 min
Design mockFree account
System design problems
Pick a problem and run a full mock. Use what you learned about the second half of the round.
45 min

Stage 2 of 3 · 1 h 36 min

The behavioural round

You have six real stories ready. You can tell a failure and a conflict honestly, and ask good questions at the end.

Lesson
Behavioural round: build your story bank
What the behavioural round tests, how to answer in the STAR shape with a result, and how to choose and write six real stories that answer many questions.
24 min
Lesson
Behavioural round: failure, conflict and saying I, not we
How to tell a real failure story and a real conflict story, when to say I and when to say we, and how to answer questions that sound like traps.
24 min
Lesson
Behavioural round: what each level shows, and your own questions
How the size of your story shows your level, which questions appear at which level, how to ask the interviewer good questions, and how to close the round.
12 min
Behavioural mockFree account
Behavioural mock interview
Tell three of your own stories to an AI interviewer who asks follow-up questions.
36 min

Stage 3 of 3 · 2 h 4 min

Your resume and the coding round

You can defend every line of your resume, and run a coding round out loud in a fixed order.

Lesson
Your resume is the syllabus: turn each line into a deep dive
How interviewers use your resume, how to write lines you can defend, and how to prepare a ten-minute deep-dive card for each line, including numbers that add up.
20 min
Resume mockFree account
Resume mock interview
The interviewer picks two points from your resume and asks about the numbers and the trade-offs.
35 min
Lesson
Running a coding round out loud
A fixed order and clock for a 45-minute coding round, and the words to say at each step: clarify, examples, brute force, improve, plan, code, dry run, cost, and what to do when you are stuck.
24 min
Coding mockCheckpointFree account
Coding mock interview
Your checkpoint: solve one problem with an AI interviewer and say your thinking out loud, step by step.
45 min

Estimates

How the time is counted

These times are planning estimates, not deadlines. Yours will vary.

Lessons and trade-off pages: the number of words divided by 130, rounded, plus 4 minutes to think.
A Drill: about 7 minutes. A system design mock: allow about 45 minutes. A machine coding mock: allow about 75 minutes.
Other mocks: a SQL mock with one problem, about 29 minutes. A behavioural mock, about 36 minutes. A resume mock, about 35 minutes. A coding mock, about 45 minutes.
A simulator level or a Cost Lab workload: allow about 15 minutes. This is our own estimate for a first try. It can take you less or more.
Incident investigation: time varies. The room has a simulated clock; your real time depends on how you investigate. It has no fixed time, so it is not counted in any total.
The total is the sum of all steps that have a time. The weeks are the hours divided by 4, rounded up. We assume 4 hours a week, like a person with a job. Doing a step again is not counted.

Ready for the checkpoint?

The last step is a mock interview with an AI interviewer. It gives you a report that shows what you did well and what was missing.

See the mock interviews All tracks