Backend Coding Challenge

Problem Statement

Construct a micro-service that, when given an link to a pdf document:

1. stores the document in local storage and
2. generates a thumbnail for the document

Technologies to use

• Typescript
• Node

Requirements

Mandatory

• Expose an endpoint where an API consumer can POST a PDF.
  • The PDF should be specified as a URL in the message body, not a file upload
  • The endpoint should respond immediately after receiving the link, without waiting for the PDF to be processed
• Expose an endpoint which returns a list of PDFs and their associated thumbnails (both as URLs).

Optional stretch goals

These are optional, do as many as you can/want

• Detect duplicates
• Push a webhook to notify the API client of the successful processing.

Submission details

• POST <base_url>/pdfs
  • minimal validation : type = pdf -> 422 if invalid
  • bdd : uuid in table "thumbnail_generation_requests"
  • starts async processing then returns 201 {id: uuid}
• Processing
  • save pdf in file system with naming "id.pdf".
  • first page extraction, conversion to png scaled to 256x256px
  • save png in file system with naming "id.png"
  • insert a end of processing event in the bdd table named "successful_thumbnail_jobs"
• GET <base_url>/pdfs-thumbnails
  • sql SELECT * from successfull_thumbnail_jobs
  • response [{id: uuid, pdf_url: <base_url>/pdfs/:id, thumbnail_url: <base_url>/pdfs/:id/thumbnail}]
• GET <base_url>/pdfs/:id
• GET <base_url>/pdfs/:id/thumbnail

Evaluation criteria

You should see this challenge as a way to showcase your software engineering skills in a professional environment.