Interview task

I decided to use RavenDB, because I am very familiar with it, and it fits perfectly for this case. Also, I want to use the opportunity to pitch this great piece of software. :)

I would do this test slightly differently in the .net world, but I tried to follow the project structure "by the book" in the Java world. So I have packages: controller, service, model, infrastructure. What I don't have is the repository package. Because I am new in the Java world, I wasn't familiar with the JpaRepository concept and how it would fit with Ravendb, so I decided not to use it for this purpose. That shouldn't be a problem, because Ravendb SDK already implements a Rep/UoW pattern.

What I think can be improved is error handling and logging. I have an exquisite way of doing that in c#, using middleware pipelines, where I log every request/response, duration of request, and a lot of other things. The same thing is with error handling. I think those two things are critical, and I would probably ask some experienced Java devs, what is best practice.

RavenDB indexes are very powerful, but I skipped it for this purpose, filtering is still very fast.

I would add paging in filtering because now the result can contain much data.

Dependency injection is something that can be improved.

Integration tests are also missing. My approach is that the test's entry point is an endpoint.

I wanted to add swagger, but I had some strange issues, so I skipped it for now.

I am using a test instance for Raven and you can see the data here after you run the project: http://live-test.ravendb.net/studio/index.html#databases/documents?&database=telemetry-test

Tech Stack

Server: Java, RavenDB

Prerequisites

Java 17+
Maven 3+

Run Locally

Clone the project

  git clone https://github.com/djordjedjukic/telemetry-data-hub.git

Go to the project directory

  cd telemetry-data-hub

Start the server

  mvn spring-boot:run

API Reference

Get all applicable filters

  GET /api/telemetry/filters

Import telemetry data

  POST /api/telemetry/import

Parameter	Type	Description
`file`	`MultipartFile`	CSV file you want to import

Filter telemetry data

  POST /api/telemetry/filter

The request body should be a JSON array of filter conditions. Each filter condition should have the following structure:

Key	Type	Description
`fieldName`	`string`	The name of the field to filter on.
`operator`	`string`	The operator to use for the filter (e.g., 'Equals', 'GreaterThan', 'LessThan', 'Contains').
`value`	`string`	The value to use for comparison.

Example

POST /api/telemetry/filter
Content-Type: application/json

[
    {
        "fieldName": "engineSpeed",
        "operator": "GreaterThan",
        "value": 1000
    },
    {
        "fieldName": "serialNumber",
        "operator": "Equals",
        "value": "A5305041"
    }
]

djordjedjukic / telemetry-data-hub