DSA prep for a backend / SDE role

Learn these first

Core topics for a backend / SDE loop — everything else waits until these hold.

• 1ArraysWalk through it →
• 2StringsWalk through it →
• 3Linked ListWalk through it →
• 4Binary TreesWalk through it →
• 5BSTWalk through it →
• 6GraphWalk through it →
• 7Dynamic ProgrammingWalk through it →
• 8StackWalk through it →
• 9QueueWalk through it →
• 10Binary SearchWalk through it →

Then these

• Backtracking
• Heap
• Two Pointers
• Sliding Window
• Recursion

Problems to start with

Named problems from this role's core topics, easiest first. Each page shows which roles treat it as core, which sheets carry it, and the companies that have asked it.

• Two Sum · Easy
• Maximum and Minimum Element in an Array · Easy
• Reverse the Array · Easy
• Contains Duplicate · Easy
• Chocolate Distribution Problem · Easy
• Best Time to Buy and Sell Stock · Easy
• Merge Sorted Arrays · Easy
• Pascal's Triangle · Easy
• Majority Element · Easy
• Sort an Array of 0s 1s and 2s · Easy
• Leaders in an Array · Easy
• Check if Array is Sorted and Rotated · Easy

What this ordering pushes down

Math, bit manipulation, tries, intervals, matrix problems, sorting and greedy sit below the core tier for backend loops. Not because they never appear, but because graphs, dynamic programming and tree traversal appear far more often and there is only so much time before the interview. Treat the lower tier as what to reach last, not what to skip: an interval-merge or a greedy scheduling question is a normal onsite warm-up.

Why an order beats a list

Every popular sheet hands all 370 problems to everyone in the same fixed sequence. A backend / SDE interview does not weight them the same way a backend interview does — so a fixed list spends your first weeks on topics your loop barely tests. Pick this role in the app and the same problems re-sequence: core topics first, the rest after.

Questions