Accept the rules
Confirm the window, the tooling policy, evidence collection, and the submission contract.
Portage
A settings-file tool from 2009 is being retired. Write the parser that replaces it, and make it agree with the tool on every file.
Open SubmissionModerate confidenceNode 22 · JavaScriptRatedRecurringSolo
TypeHidden Gauntlet
Recurring: enter again after a result to beat your best score. Your best result counts, and your rating moves only on your first attempt.
- Opens
- Oct 1812:00 UTC
- Closes
- Oct 1912:00 UTC
- Effort
- 40 min
- Entered
- 2
- XP
- 120
Intermediate1260
Author estimate · calibrating (0 attempts)Need a rules clarification?
Ask before you start. The clock cannot be paused once your window opens.
01
Specification
Challenge brief
- Type
- Hidden Gauntlet
- Stack
- Node 22 · JavaScript
- Format
- Daily Problem · Open Submission · Solo
- Time
- 40 min
Overview
The tool that has read the company's settings files since 2009 runs on one old host and is being retired. Its documentation covers the basics; the files in use rely on behaviour it never mentioned. Write parse so that it returns, for every file, exactly what the tool prints. You can ask the tool what it makes of a file 25 times, 240 bytes at a time.
What is tested
- Legacy behaviour
- Differential testing
- Choosing what to ask
Acceptance criteria
- 1A parse function that agrees with the legacy tool on every settings file.
- 2The public suite still green.
Rules
- Work solo in the private repository Finals creates when you enter.
- The legacy host answers 25 queries per attempt, each at most 240 bytes.
- No external network access during evaluation.
Diagnosis, validation, and repair are scored. Submission speed is not.
02
Execution contract
Runtime and interface
You are given a Node 22 · JavaScript codebase and work inside it. The stack is fixed for this challenge.
BoundaryCLI
Start commandnode --test test/*.test.js
Portn/a
Health checkn/a
03
Open Submission session
How competing works
Finals creates your attempt repository
A private repository, seeded with the challenge. You get one clone command and your clock starts.
Work in your own environment
Use any editor, agent, or model. Declare your tooling; it is recorded on your result.
Run the pre-flight check
Confirm at any time that your submission builds, starts, and answers its health check.
Push to main before the deadline
Your last push received on main before the deadline is your submission. Submit early if you are done.
Grading runs your commit
Your submission is built and run in an isolated environment: public tests, hidden tests, edge cases, security scans, and two independent code reviews.
Read the scorecard
What passed, what failed, where points were lost, and how stronger submissions differed.
04
Evaluation
Scoring model
Automated checks make up most of the score. Two independent code reviews cover what tests cannot, and every review finding cites a file and line.
Workflow is not scored on this challenge.
The “AI workflow and verification” band (15%) requires the Finals companion, which Open Submission does not use. Its weight is spread across the remaining bands. The percentages below are the ones applied.
Functional correctness64%
Hidden and edge-case testing18%
Architecture and code quality12%
Security and resilience6%
Build, startup, public and hidden tests, edge cases, performance, dependencies, security, and accessibility where relevant.
Two independent code reviews, each by a different model. Every finding cites a file and line.
Not scored at this tier. Requires the Finals companion session log.
05
Verification tier
Open Submission
What this result verifies
Your submitted commit is graded in an isolated environment, and its push history is confirmed against the challenge window.
Mints a credentialPrize eligibleMoves your rating
06
Privacy
What Finals records
Public by default
Score band, discipline, calibrated difficulty, verification tier, placement, and rating movement.
Private unless you publish
Score breakdowns, failing tests and their inputs, review findings, how stronger submissions differed, repository contents, and transcripts.
Never collected
Keystrokes and screen recordings, except during a live round you opt into. Secrets are redacted on your machine before anything is uploaded.