Featured ticket
Stockroom: read an unfamiliar stock service, fix three reports, add low-stock alerts, then make reservations fast
You have just joined the checkout team, and the stock service in stockroom/ is yours now. Nobody who wrote it is around. Read README.md and the code first: the reports be…
Read the ticketRetail45 min
All tasks
- Stockroom: read an unfamiliar stock service, fix three reports, add low-stock alerts, then make reservations fastLanguage:PythonRetailBug fix45 min
- Logpipe: read an unfamiliar log pipeline, fix three reports, add a feature, then make ingest fastLanguage:PythonSaaSBug fix45 min
- Calendar: midnight meetings refused, clashes let through, jumbled free slots and repeated idsLanguage:PythonSaaSBug fix30 min
- Calendar: book slots in a 24-hour day, then times of day, cancelling and free slotsLanguage:PythonSaaSFeature35 min
- Legacy debugging set: seven catalog helpers, one bug eachLanguage:PythonRetailBug fix25 min
- Legacy debugging set: seven warehouse helpers, one bug eachLanguage:PythonLogisticsBug fix25 min
- Legacy debugging set: seven checkout helpers, one bug eachLanguage:PythonRetailBug fix25 min
- Logger: alerts held back too long, retries that extend the wait, and stale tracked countsLanguage:PythonSaaSBug fix25 min
- Logger: print each message at most once every ten seconds, in bounded memoryLanguage:PythonSaaSFeature25 min
- Text editor: redo brings back stale edits, undo stops at nine, backspace breaks the cursor and undo loses itLanguage:PythonSaaSBug fix35 min
- Text editor: undo and redo the last ten editsLanguage:PythonSaaSFeature35 min
- Text editor: typing, backspace, a cursor, and copy and pasteLanguage:PythonSaaSFeature25 min
- Bank: whole balances refused, ranking ties reversed, expired holds kept and merged accounts losing transfersLanguage:PythonFinanceBug fix40 min
- Bank: merge two accounts without losing money or pending transfersLanguage:PythonFinanceFeature35 min
- Bank: hold transfers until the receiver accepts, and expire them after an hourLanguage:PythonFinanceFeature40 min
- Bank: open accounts, move money and rank the top spendersLanguage:PythonFinanceFeature30 min
- In-memory database: values outlive their TTL, prefix scans match mid-word and history keeps deleted valuesLanguage:PythonSaaSBug fix40 min
- In-memory database: read a field as it was at an earlier timeLanguage:PythonSaaSFeature40 min
- In-memory database: add values that expire (TTL)Language:PythonSaaSFeature35 min
- In-memory database: build records, compare-and-set and sorted scansLanguage:PythonSaaSFeature30 min
- A schema with a field called parent cannot have date fieldsLanguage:PythonSaaSBug fix25 min
- None items in a list of nested objects are mishandledLanguage:PythonHealthcareBug fix30 min
- TimeDelta dumps some durations one unit shortLanguage:PythonFinanceBug fix25 min
- Unknown keys that contain a dot are turned into nested dictsLanguage:PythonWeb3Bug fix20 min
- Dumping a list or dict through a Boolean field raises TypeErrorLanguage:PythonRetailBug fix15 min
- A list of datetimes makes a schema unusableLanguage:PythonFinanceBug fix25 min
- A field whose data key is the empty string cannot be loaded or dumpedLanguage:PythonLogisticsBug fix30 min
- Nested field with a schema instance and only= raises TypeErrorLanguage:PythonRetailBug fix25 min
- A field marked both load_only and dump_only is still loadedLanguage:PythonHealthcareBug fix20 min
- DateTime field reads true and false as timestampsLanguage:PythonFinanceBug fix15 min
- DateTime field rejects the timestamp 0Language:PythonLogisticsBug fix15 min
- Error for a field declared as a class shows raw placeholdersLanguage:PythonSaaSBug fix10 min
- NaN in a TimeDelta field crashes loadingLanguage:PythonLogisticsBug fix15 min
- A huge timestamp crashes loading instead of failing validationLanguage:PythonFinanceBug fix20 min
- Errors from schema-level validators are reported under the attribute nameLanguage:PythonHealthcareBug fix30 min
- URL validator rejects file URLs that have no hostLanguage:PythonLogisticsBug fix20 min
- URL validator gets the user and password part wrongLanguage:PythonWeb3Bug fix30 min
- Enum field accepts names that are not membersLanguage:PythonHealthcareBug fix20 min
- A Constant field cannot be marked requiredLanguage:PythonFinanceBug fix25 min
- Partial loading does not reach a nested field that has a data keyLanguage:PythonRetailBug fix30 min
- OneOf.options() invents entries when there are more labels than choicesLanguage:PythonRetailBug fix15 min
- Email validator accepts international domains that start or end a label with a hyphenLanguage:PythonSaaSBug fix30 min
- URL validator rejects a link whose fragment follows the domainLanguage:PythonSaaSBug fix15 min
- sort misplaces items that lack the property, and sort_natural ignores nested propertiesLanguage:TypeScriptRetailBug fix35 min
- A range written with spaces around the dots is silently emptyLanguage:TypeScriptSaaSBug fix30 min
- block.super throws in strict mode and cannot be used as a valueLanguage:TypeScriptSaaSBug fix40 min
- Nothing renders after a for loop that used break or continueLanguage:TypeScriptSaaSBug fix30 min
- where_exp, group_by_exp and find_exp cannot see other variablesLanguage:TypeScriptRetailBug fix30 min
- slice returns content when the start is before the beginningLanguage:TypeScriptRetailBug fix15 min
- round moves negative halves toward zeroLanguage:TypeScriptFinanceBug fix15 min
- modulo gives the wrong result when one side is negativeLanguage:TypeScriptSaaSBug fix15 min
- url_decode turns an encoded plus sign into a spaceLanguage:TypeScriptRetailBug fix15 min
- truncatewords returns one word too few when the text starts with whitespaceLanguage:TypeScriptRetailBug fix15 min
- The %s Unix timestamp changes with the display timezoneLanguage:TypeScriptSaaSBug fix30 min
- Week-of-year date formats %U and %W return the wrong weekLanguage:TypeScriptSaaSBug fix30 min
- strip, lstrip and rstrip leave emoji in place when asked to trim themLanguage:TypeScriptRetailBug fix35 min
- Calculator returns plausible but wrong answersLanguage:PythonSaaSBug fix30 min
- Client library fails the strict buildLanguage:TypeScriptSaaSBug fix25 min
- Pipeline reports success before events finishLanguage:TypeScriptSaaSBug fix40 min
- Calendar service: duplicate requests, meetings over protected time, lost executive slots and rejections that don't stickLanguage:PythonSaaSBug fix45 min
- Session service: sessions that outlive their expiry, a refresh that does nothing and a store that never shrinksLanguage:PythonSaaSBug fix45 min
- LRU cache: the newest entry is evicted and reads and updates do not keep keys freshLanguage:PythonSaaSBug fix45 min
- Market data service: stale quotes, ghost subscribers, one bad client blocking fan-out and deltas with no snapshotLanguage:PythonFinanceBug fix45 min
- Fulfillment service: stock promised twice, oversold reservations and releases that free nothingLanguage:PythonRetailBug fix45 min
- Message bus: wildcard subscriptions that never match, unsubscribes that do nothing and one bad subscriber that blocks the restLanguage:PythonSaaSBug fix45 min
- Matching engine: orders that jump the queue, partial fills that vanish and cancels that do nothingLanguage:PythonFinanceBug fix45 min
- Cart totals come out wrongLanguage:TypeScriptRetailBug fix30 min
- Risk netting: sells add to positions, replayed trades count twice and counterparties share a netLanguage:PythonFinanceBug fix45 min
- Job queue: work handed out twice, acked jobs redelivered and retries that never dead-letterLanguage:PythonSaaSBug fix45 min
- Tick rounding: prices always round down instead of to the nearest tickLanguage:PythonFinanceBug fix35 min
- Trade settlement: resent fills count twice, PnL uses the wrong cost and bad fills get throughLanguage:PythonFinanceBug fix35 min
- Order identifiers: codes lose their zero padding and broken codes pass validationLanguage:PythonRetailBug fix35 min
- Amount split: remainder cents go missingLanguage:PythonFinanceBug fix35 min
- Retry backoff: delays start too high and ignore the capLanguage:PythonSaaSBug fix35 min
- Interval merge: unsorted input breaks merging and touching intervals stay apartLanguage:PythonSaaSBug fix35 min
- Rolling statistics: windows come up one short, averages round down and the max returns the minLanguage:PythonSaaSBug fix35 min
- Transaction fees: boundary amounts land in the wrong tier and small fees skip the minimumLanguage:PythonFinanceBug fix35 min
- Rate limiter: one call too many gets through every windowLanguage:PythonSaaSBug fix35 min
- Payments service: double charges, overdrafts, stuck holds and a ledger that won't balanceLanguage:PythonFinanceBug fix45 min
- Pooled draw: codes lose their zeros and payouts overspend the potLanguage:PythonFinanceBug fix35 min
- Flow collection map key throws IMPOSSIBLE error when preceded by blank line or commentLanguage:TypeScriptSaaSBug fix40 min
- Parsing a weekday followed by a relative offset returns a result with a contradictory weekdayLanguage:TypeScriptSaaSBug fix30 min
- Cron parser hangs on extremely long lists of repeated field valuesLanguage:TypeScriptSaaSBug fix30 min
- Day-of-week step interval incorrectly schedules jobs on SundaysLanguage:TypeScriptSaaSBug fix30 min
- Expressions with fewer than five fields are parsed into incorrect slotsLanguage:TypeScriptSaaSBug fix30 min
- Sessions come out wrong when log events arrive out of orderLanguage:PythonSaaSBug fix35 min
- Scheduler double-books rooms and skips rooms that fit exactlyLanguage:PythonSaaSBug fix35 min
- Inventory reservations drift out of sync with stockLanguage:PythonRetailBug fix35 min
- list_tasks returns every task when a status is givenLanguage:PythonSaaSBug fix30 min
- GET /tasks ignores the status filterLanguage:TypeScriptSaaSBug fix30 min