Simplify processing Proof of Delivery for Logistics Company

Client : Stealth mode startup in Logistics Domain


  • In its early form, the product is just couple of APIs
    • First API accepts publicly accessible image file URL, and returns the POD number
    • Stats API returns various data related to past API calls.
  • Multi-tenant support since each customer has different POD format.
  • Support for multiple POD formats for single customer.
  • Product available as APIs that can be integrated into customer's existing system.
  • APIs available on the RapidAPI market place.
  • Pay-per-use pricing


  • Backend : Python 3, FastAPI for REST API server, Google Vision API
    • Testing : pytest
    • Documentation : FastAPI, Swagger, OpenAPI
  • Database : Postgres
  • PaaS : Heroku
  • Marketplace : RapidAPI

My Role

As An Architect and the Back-end Engineer, I was the and only engineer on the development team.

I worked with the founders and Domain experts to understand the requirements.

The potential customer already had their systems in place, and they only wanted to simplify processing the POD

Both FastAPI (my choice) and RapidAPI market place (Business Choice) was new for me. I had great time learning the FastAPI framework and exploring the RapidAPI.

Design considerations and Choices

OCR is the critical component of the product. We considered options like Tesseract in the beginning, but decided to use Google Cloud Vision to better Developer productivity. It is easier to use and no setup required. The plan was to replace it some library that the business would not have to pay for.

In past, I have worked (and deployed in production) Eve framework, which is based on top of Flask. But that was couple years ago.

This time, I chose FastAPI for the developer productivity and for its async support. Use of Pydantic was very interesting and helpful.

Initially, there was no database since we assumed RapidAPI would provide the Stats about the API calls. But it turned out to be limiting. Additionally, the Stats provided by RapidAPI were available only from their Dashboard, and were (ironically) not accessible via API. So we decided to provide our own API

Project Duration

Dec 2019 - Feb 2020