How to Prepare for a Coding Interview in 2026

Technical interviews haven't gotten easier — they've gotten more predictable. The same patterns show up again and again. Here's a structured, no-fluff prep guide.

The 4-Week Study Plan

Week 1: Data Structures

• Arrays & Strings — Two Sum, Sliding Window, Two Pointers
• Hash Maps — Frequency counting, grouping, caching
• Linked Lists — Reversal, cycle detection, merge
• Stacks & Queues — Monotonic stack, BFS queue

Week 2: Trees & Graphs

• Binary Trees — DFS (pre/in/post order), BFS
• BSTs — Validation, search, insert
• Graphs — BFS, DFS, topological sort, Union-Find
• Heaps — Top-K problems, merge K sorted lists

Week 3: Dynamic Programming & Advanced

• 1D DP — Climbing stairs, house robber, coin change
• 2D DP — Unique paths, longest common subsequence
• Backtracking — Permutations, subsets, N-Queens
• Binary Search variations — Search in rotated array, find boundaries

Week 4: System Design & Behavioral

• System design — URL shortener, chat app, rate limiter
• Behavioral prep — 5 STAR stories ready to go
• Mock interviews — At least 3 practice sessions
• Salary research — Know your market rate

The 8 Patterns That Solve 90% of Problems

Don't grind 500 LeetCode problems. Learn these 8 patterns and you can solve most interview questions:

1. Two Pointers — Sorted arrays, pair finding
2. Sliding Window — Subarray/substring optimization
3. Binary Search — Sorted data, boundary finding
4. BFS/DFS — Trees, graphs, connected components
5. Dynamic Programming — Overlapping subproblems
6. Backtracking — Combinations, permutations
7. Monotonic Stack — Next greater/smaller element
8. Prefix Sum — Range sum queries

System Design Framework

Use this 4-step framework for every system design question:

1. Clarify requirements (2 min) — Functional + non-functional
2. High-level design (5 min) — Draw the architecture
3. Deep dive (15 min) — Database schema, API design, key decisions
4. Scaling (5 min) — Bottlenecks, caching, sharding

The STAR Method for Behavioral Questions

Prepare 5 stories that can be adapted to any behavioral question:

• A project that succeeded (highlight your contribution)
• A project that failed (highlight what you learned)
• A time you disagreed with someone (highlight resolution)
• A time you led something (highlight impact)
• A time you dealt with ambiguity (highlight decision-making)

Salary Negotiation — Don't Skip This

Most developers leave $10K-30K on the table by not negotiating. Three rules:

1. Never give your number first. Let them make the offer.
2. Always negotiate. The first offer is never the best offer.
3. Negotiate more than salary. Signing bonus, equity, PTO, remote days.

Good luck. You've got this.