Working out whether you need this

Before committing forty hours, work out whether you need them. Algorithm rounds have not disappeared, but they have not stayed everywhere either, and which you face depends on the specific companies you are applying to. This section lays out that split, names the short pattern list that covers almost everything still asked, and says plainly which classic topics you can skip. Read it and decide; skipping this track deliberately is a legitimate outcome.

It depends on the company, not the year#

Whether you face an algorithm round is not a function of how modern the role is. Reported 2026 loops suggest a fairly clear split: algorithm rounds survive at large companies and at platform or infrastructure roles, and largely disappear at product-focused AI companies where agents and retrieval are the product.

Still asking algorithm questions:
  large technology companies
  AI infrastructure and platform roles
  established enterprises hiring AI engineers

Often not:
  AI-native product companies
  forward deployed and applied roles
  small teams hiring for shipping speed

The whole practical surface#

Interview algorithm questions draw from a much smaller set than the field contains. Learn these eleven patterns properly and you can approach almost anything you will be asked.

1. 1.Hash maps and arrays
2. 2.Two pointers
3. 3.Sliding window
4. 4.Binary search, including on the answer space
5. 5.Stacks, including monotonic stacks
6. 6.Heaps and top-k
7. 7.Intervals
8. 8.Trees: breadth-first and depth-first
9. 9.Graphs: traversal and topological sort
10. 10.Recursion and backtracking
11. 11.One-dimensional dynamic programming

What to skip#

• Two-dimensional and bitmask dynamic programming. Rare, and hard enough to consume disproportionate time.
• Segment trees, Fenwick trees, union-find beyond the basic idea.
• Maximum flow, matching, advanced graph algorithms.
• Competitive programming techniques generally. Different game, different rules.

The temptation is to keep learning further patterns because each feels like progress. Depth on the eleven beats breadth beyond them, because the eleven actually recur.