The project questions on HackerRank utilize VM-based containers, with specific limitations on the number of available workspaces for a company at any given time.
Limitations by Question Type:
- Logins per Minute: The maximum number of candidates who can log into a test from a company in any given minute.
- Workspace: A container assigned to a project question. Each project question uses one independent workspace.
- Concurrent Workspaces: The total number of containers that a company can utilize simultaneously.
| Question Type | Logins Per Minute | Concurrent Workspaces |
| Front-end | 100 | 1000 |
| Back-end | 100 | 1000 |
| Full-stack | 100 | 1000 |
| Data Science | 100 | 1000 |
| DevOps | 10 | 100 |
Example
If a test includes two project questions:
- Maximum Logins: 100 candidate logins per minute.
- Simultaneous Test takes: Up to 500 candidates
- Concurrent Workspaces: 1000 concurrent workspaces (each candidate will utilize 2 workspaces (one for each project question)
Candidate Experience
Generally, candidates can log in without any issues. However, if the limits are exceeded they will
experience the following when:
1. Logins per Minute are at Capacity: When login capacity is reached, candidates will see a message indicating their login is temporarily throttled. A countdown will replace the "Try Again" button, and once it finishes, candidates will be provisioned servers.
2. Concurrent Workspaces are at Capacity: If the concurrent workspace limit is exceeded, the remaining candidates will see an error message: "Our servers are at capacity. Please try to take this test after some time." As candidates complete their attempts, new candidates will be allowed to log in.
Note: Reach out to support@hackerrank.com if your requirement exceeds the default threshold. Given the limitations, it's recommended to invite candidates in batches to stagger logins. Also irrespective of the duration of the test, the limits remain the same as mentioned in the table above.