Outlyer backend recruitment test

Thanks for taking the time to do our backend coding test. The challenge has two parts:

• A coding test
• A few follow-up questions

Coding Test

• Write a well structured program which provides an API with the endpoint /metrics that returns some system metrics in JSON.

• The program should periodically collect and keep values of the system cpu, memory, disk and network metrics in a registry in memory.

• The program should expose the registry values when an http GET request is made to /metrics.

• Example output (minimum expected metrics to collect/send, although more can be added):

$ curl localhost:8080/metrics
{
    "sys.cpu": "4.15",
    "sys.mem.active": "8029741056",
    "sys.mem.available": "6602049536",
    "sys.disk.free": "13605457920",
    "sys.disk.used": "76558884181",
    "sys.net.rx": "217003.31",
    "sys.net.tx": "11390.29"
}

Implementation

• The code can be written in any language.

• Metric collection should work on UNIX Operating systems.

• You will be evaluated both on your implementation choices and the quality of your code; so please ensure code is well structured, extensible, tested, readable, commented etc.

• bonus point: design your solution so that it can be easily extended to support collecting stats from other applications or services, for example ones running on your host like nginx or redis etc.

Submission Guidelines

• Please submit your application as a repository on GitHub.

• Please submit an explanation document for your work addressing all the follow-up questions. This should be no more than 1000 words

• Please let your Outlyer contact know when you've uploaded your solution.

Follow-up Questions

• Which parts did you spend the most time with?

• How long, in hours, did you spend on the test?

• What did you find to be the most difficult?

• What would you add to your solution if you had more time?

• Why did you choose this programming language ?

• How did you find the test overall? If you have any suggestions on how we can improve the test, we'd love to hear them.