Problem Bank - 1,204 real OAs

Practice the OA
companies are actually sending.

Company-scoped online assessments from 220 companies, tagged by cohort and wired into a real editor with runnable tests. Stop guessing which topic list matches Stripe this quarter.

1,204
real OA problems
+38 / mo
220
companies covered
+12 / mo
47
patterns mapped
DP - graph - two-ptr
5.0ms
median runtime
py - go - ts - rs
A run-through

Scope / Solve / Review.

Three minutes inside the bank.

bank - filter1,204 -> 12
company
StripeDoorDashAirtable+217
cohort
Q3 2026Q2 2026Q1 2026archive
difficulty
easymediumhard
pattern
DPgraphdesigntwo-ptr+43
12 matchedfrom 1,204
47 patterns

Mapped to the structures companies actually ask.

Pattern heat reflects how often this quarter's OAs use it.

Arrays - two-pointer
142
Hash maps - sets
118
Sliding window
87
Binary search
76
Stack - monotonic
64
Linked list
42
Trees - BST
91
Trees - trie
38
Graph - BFS - DFS
124
Graph - shortest path
56
Topological sort
28
Union-find
31
DP - 1D
73
DP - 2D
68
DP - bitmask
21
Greedy
84
Backtracking
47
Heap - priority queue
52
Math - number theory
36
Bit manipulation
24
Design - rate limit
18
Design - cache
22
Concurrency
15
System simulation
33
Bank to Signal

The bank knows what is being asked right now.

When tracked inboxes start seeing Stripe OAs land, the Q3 set surfaces to the top. You practice this quarter's questions, not the ones that were popular in 2019.

  • Problems get a HOT mark when an OA spikes in tracked inboxes.
  • Each company set is dated and prioritized by freshness.
  • Frozen cohorts drop in priority so you do not waste reps.
See live signals
signal -> bank - last 7 dayslive
Stripe+12.4%promoted Q3 set47 pr
DoorDash+8.1%added 4 new problems32 pr
Anthropic+6.2%new cohort opened18 pr
Airtable+3.0%refreshed test cases28 pr
Adobe-2.1%lowered priority22 pr
Teslafrozenarchived19 pr
auto-curated - refreshed hourly
FastPrep vs generic banks

Practice by target, not by folklore.

FastPrepGeneric question banks
Company cohort taggingY~
Runnable editor + hidden testsY~
Hiring-signal prioritizationY-
Post-pass approach reviewY~

Practice the set before it hits you.

Open the bank, pick your target company, and run the exact style of OA you are likely to see this week.