Data Engineering coding interview prep
SQL, Python, and problem-solving patterns for Senior DE interviews. Structured as a 90-day schedule you can follow at your own pace — use the calendar on the left to jump to any published day.
Covers SQL drills, Python patterns, complexity, and maintenance-minded solutions — aligned with how Meta, Netflix, and Google evaluate data engineers.
Coding track
A structured 90-day path: arrays, hashing, and strings through trees, graphs, heaps, and dynamic programming—plus design-style problems, phase reviews, and full mocks that mirror how Meta, Google, Netflix, and similar companies run data-engineering and general coding screens.
Pick a day from the calendar on the left or from the list below. On each lesson, use the 30-minute timer and mark complete to track progress in this browser—no account required.
- Day 0 Day 0 — 90-Day Coding Interview Prep Course Overview
- Day 1 Two Sum
- Day 2 Valid Anagram
- Day 3 Group Anagrams
- Day 4 Top K Frequent Elements
- Day 5 Product of Array Except Self
- Day 6 Longest Consecutive Sequence
- Day 7 Review – Week 1
- Day 8 Valid Palindrome
- Day 9 3Sum
- Day 10 Container With Most Water
- Day 11 Best Time to Buy & Sell Stock
- Day 12 Longest Substring Without Repeating Characters
- Day 13 Binary Search + Search Insert Position
- Day 14 Review – Week 2
- Day 15 Reverse Linked List
- Day 16 Merge Two Sorted Lists
- Day 17 Linked List Cycle + Cycle II
- Day 18 LRU Cache
- Day 19 Min Stack
- Day 20 Valid Parens + Min Remove Parens
- Day 21 Review + Phase 1 Assessment
- Day 22 Invert Binary Tree
- Day 23 Maximum Depth of Binary Tree
- Day 24 Binary Tree Level Order Traversal
- Day 25 Binary Tree Vertical Order
- Day 26 Lowest Common Ancestor
- Day 27 LCA of Binary Tree III
- Day 28 Review – Week 4
- Day 29 Number of Islands
- Day 30 Clone Graph
- Day 31 Course Schedule
- Day 32 Course Schedule II
- Day 33 Word Ladder
- Day 34 Accounts Merge
- Day 35 Review – Week 5
- Day 36 Kth Largest Element in Array
- Day 37 Find Median from Data Stream
- Day 38 Merge Intervals
- Day 39 Meeting Rooms II
- Day 40 Task Scheduler
- Day 41 Non-overlapping Intervals
- Day 42 Review – Week 6
- Day 43 Climbing Stairs
- Day 44 House Robber
- Day 45 Coin Change
- Day 46 Longest Increasing Subsequence
- Day 47 Unique Paths
- Day 48 Word Break
- Day 49 Review + Phase 2 Assessment
- Day 50 Serialize / Deserialize Binary Tree
- Day 51 Binary Tree Max Path Sum
- Day 52 Alien Dictionary
- Day 53 Graph Valid Tree
- Day 54 Minimum Height Trees
- Day 55 Network Delay Time
- Day 56 Review – Week 8
- Day 57 Design HashMap
- Day 58 Snapshot Array
- Day 59 Time Based Key-Value Store
- Day 60 Key-Value Store with TTL (custom)
- Day 61 Implement Trie
- Day 62 Design Twitter
- Day 63 Review – Week 9
- Day 64 Basic Calculator II
- Day 65 Trapping Rain Water
- Day 66 Median of Two Sorted Arrays
- Day 67 Regular Expression Matching
- Day 68 Longest Valid Parentheses
- Day 69 Sliding Window Maximum
- Day 70 Review + Phase 3 Assessment
- Day 71 Random Pick with Weight
- Day 72 Subarray Sum Equals K
- Day 73 Min Remove Valid Parens (re-solve)
- Day 74 Nested List Weight Sum
- Day 75 Dot Product of Sparse Vectors
- Day 76 FULL MOCK: Meta
- Day 77 REVIEW — Meta Mock
- Day 78 Longest Palindromic Substring
- Day 79 Decode Ways
- Day 80 Search in Rotated Sorted Array
- Day 81 Number of Connected Components
- Day 82 Rate Limiter (coding + design)
- Day 83 FULL MOCK: Google
- Day 84 REVIEW — Revisit hardest
- Day 85 Progressive KV Store (Anthropic style)
- Day 86 Version-Controlled Data Structure
- Day 87 Debug & Optimize Caching System
- Day 88 FULL MOCK: Random
- Day 89 FULL MOCK: Weakest Topic
- Day 90 FINAL REVIEW