Coding interview practice in real repositories
Investigate a bug, review an AI proposal, and verify a change in an existing application. Explore each scenario before you start an interview.
25 problems
Add stock filters to an inventory browser while preserving category selection, display order, and page totals.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Centralize authorization across reads, updates, lists, and administrative access.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Replace a per-row lookup with one batched load without changing the report output.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Re-derive every entry checksum so edited content cannot hide behind an intact chain.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Repair integer-cent receipt totals while preserving saved-cart inspection and checkout.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Preserve fractional refill credits while isolating client quotas.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Fix sparse preference updates so false, midnight, and an explicit clear reach the notification desk.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Hybrid Retrieval
FreeRepair reciprocal rank fusion in a retrieval workbench while preserving catalog tools and search explanations.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Evict samples outside the window and rank percentiles correctly so a stale burst stops skewing the dashboard.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Repair a community directory response so storage metadata and private contact fields stay private.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Track consecutive failures and a half-open trial so a recovered dependency is used again.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Repair tied-timestamp cursors, tenant isolation, and end-of-feed detection.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Handle retries, invalid events, and conflicting identities without corrupting balances.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Replace serialized comparison with a structural walk that reports where values diverge.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Build a quote-aware field scanner so imported data survives commas inside values.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Repair historical feature reconstruction so late data, corrections and deletions cannot leak into training rows.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Handle duplicate deliveries, stale versions, and tombstones in a projection service.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Ship resilient retries without duplicating writes or resetting request deadlines.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Repair threshold decisions and confusion-matrix metrics in a model evaluation desk.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Build reproducible deployment waves with cycle and missing-service diagnostics.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Untangle expiration, recency, and cached null values in a shared cache.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Enforce the version check a collaborative writer skips, so a stale edit loses instead of winning.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Introduce expiring leases and ownership checks for concurrent workers.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Redact nested credentials without damaging ordinary event data.
TypeScript, Python, Java, C, C++, Go (Golang), Rust
Replace modulo sharding with a hash ring so a joining node moves few keys, not all of them.
TypeScript, Python, Java, C, C++, Go (Golang), Rust