Technical Interview Preparation: A 4-Week Plan for Busy Engineers

Most interview prep advice assumes you have unlimited time and infinite motivation. Reality: you have a job, a life, and roughly an hour a day. This plan is built for that reality — four weeks, about an hour on weekdays, a bit more on weekends, covering the three rounds that decide most tech hires: coding, system design, and behavioral.

Week 1: Audit and foundations

Don't start by grinding random problems. Start by finding out where you actually stand.

• Day 1–2: Do two timed coding problems cold (one easy, one medium) and one system design question out loud to a rubber duck. Note honestly where you stalled.
• Day 3–5: Review only the data structures your audit exposed. For most people that's hash maps, two pointers, and tree traversal — not obscure dynamic programming.
• Weekend: Write your "story bank": six work stories covering a conflict, a failure, a technical win, a deadline crunch, a disagreement with a decision, and something you're proud of. One paragraph each, structured as situation → action → result.

Week 2: Coding patterns, not problem counts

Interviewers reuse patterns, and roughly ten of them cover the large majority of questions: two pointers, sliding window, hash map counting, BFS/DFS, binary search, heaps, intervals, linked list manipulation, basic recursion with memoization, and stack-based parsing.

• Do one problem per pattern per day — two on days you have energy. Quality over quantity: after solving, spend ten minutes asking what signals the pattern ("sorted array + pair search → two pointers").
• Always code in your interview language, in a plain editor without autocomplete, and talk out loud while doing it. The narration is the skill being tested.
• If you use AI assistants daily at work, practice without them. Interviews still test unassisted fluency, and the rust is real.

Week 3: System design and behavioral

System design fails are almost never knowledge fails — they're structure fails. Learn one framework and apply it every time:

• Requirements (5 min): clarify users, scale, read/write ratio, latency needs. Asking questions here scores points; assuming loses them.
• High-level design (10 min): boxes and arrows — clients, API layer, services, database, cache.
• Deep dive (15 min): pick the hardest component and go deep — data model, sharding, queue behavior under load.
• Trade-offs (5 min): name what breaks at 10x scale and what you'd monitor.

Do three designs this week (a URL shortener, a chat app, a news feed are the classic trio). For behavioral prep, rehearse your Week 1 story bank out loud — once each is enough. The goal is retrieval speed, not a script.

Week 4: Simulation and sharpening

• Do at least two full mock interviews under real conditions — a friend, a peer from a community, or a paid mock. Nothing exposes gaps like live pressure.
• Re-solve the problems you failed in weeks 1–3 from scratch. Repetition on your personal weak set beats novelty.
• Prepare your questions for the interviewer: team structure, on-call load, how success in the role is measured at six months. Good questions are scored, silently.
• The day before: stop. Cramming the final evening measurably hurts performance. Sleep is preparation.

If you have less than four weeks

Compress by cutting scope, not depth: keep the audit, cover only the five most common coding patterns, do one system design, and never skip the story bank — behavioral rounds are the cheapest points you'll ever earn. And keep applying while you prep; real interviews are the best mock interviews, and pipelines take weeks to convert anyway. The perfect moment to start applying never arrives — the prepared-enough moment is closer than you think.