How to Prepare for a Technical Interview in 30 Days

You have thirty days until the interview. Most technical interview preparationplans you will find are a list of two hundred problems and an instruction to grind. That plan fails for a specific, measurable reason: it trains the one skill you probably already have and none of the three you are actually assessed on. Here is a schedule built the other way round.

What is actually assessed

Sit in on debriefs and the same four notes appear on every scorecard, in roughly this order of weight. Notice that only one of them is "did they solve it".

Three of the four are trained by something other than solving more problems. That is the whole argument for the schedule below.

The thirty-day plan

Week 1 - patterns, not problems

Do not work through a numbered list. Work through techniques: two pointers, sliding window, binary search on the answer, breadth-first search, backtracking, and the two or three dynamic programming shapes that actually recur. Three problems from one technique in a sitting teaches more than nine unrelated ones, because the thing being learned is recognition, not the answer.

Week 2 - start speaking

This is the week most plans skip and most candidates fail on. Solve aloud, to a rubber duck if nothing else, and add one mock interview where somebody or something can interrupt you. The first time you do this it will be humiliating. Explaining a solution you already understand is a genuinely separate skill, and it is unpractised in almost everyone.

"If you can't explain it simply, you don't understand it well enough."
- widely attributed to Albert Einstein

Week 3 - full loops

One complete mock a day, then read the transcript. The transcript matters more than the score. You are looking for the moment you went quiet, the point where you started coding before agreeing an approach, and the follow-up you answered with a guess. Those three moments are where interviews are lost, and none of them appear in a problem archive's pass or fail.

Week 4 - simulate, then stop

Two full loops early in the week, then taper. Cramming the day before an interview measurably harms performance; the failure mode is not forgetting the material but arriving depleted. Sleep is preparation. Use the last two days to reread your own notes on the moments you went quiet, and nothing else.

If you have less than thirty days

The pattern in that table is deliberate. Under time pressure the instinct is to cut mocks and keep solving, because solving feels productive and mocks feel exposing. Do the opposite. The exposure is the point - better to meet it on a Tuesday than in the interview.