vnguyencode/logisticsystem

Vincent Nguyen - Zipline Logistic Take Home

Requirements

Listed below are the key requirements for the inventory management and order processing system:

• Manage an inventory of products
• Keep track of which items have been stocked
• Transforming incoming orders into outgoing shipments as appropriate

Edge cases to consider

• Max package size is 1.8kg, therefore breaking order into mulitple packages
• Out of inventory, in which case we ship what we can, and then wait until a restock happens
• When a restock happens, ship out pending items that weren't fulfilled immediately

Diagrams

Sequence Diagram

DB Diagram

Completed

Init_catalog - will initially populate (product-info) to the catalog table with the initial quantity of 0 for each product type

Process_order - will primarily do the following key things

1. Checks to see if the order received is a new or existing pending order * If new order, saves to orders table before querying * If existing order, queries table * I'm only pulling orders that have outstanding qty of products that needs to be fulfilled

2. Go through the order 1 qty at a time

3. Check if we have stock for 1 qty of the product and if we do

   • If adding 1 qty of the item doesn't exceed 1800g shipment package, then we add
   • Else if adding the 1 qty of the item to the shipment package > 1800g, then we ship out the package we have

4. We invoke ShipAPI as many times as we need - continously updating the outstanding qty field of our orders table

Connected to DB - Both of the routes mentioned above have a fully functional PostgresSQL DB hosted on ElephantSQL

Not Completed

Init_catalog - I did not have time to finish coding this out, but have included my pseudo code as to how I might have approached it with more time

Typescript - Added types where I could but not fully exhaustive

Optimizations Considerations

1. Where possible - I considered doing a bulk add of information to the DB to minimize hitting the DB frequently, I implemented this in init catalog

2. Because I'm iterating through 1 quantity of each product during process_order at a time and making multiple requests to the DB, this could lead to a heavy load on the DB and not the most optimal. I took a very brute force solution to the problem

3. I'm aware that this could be a relevant knapsack algorithm which I could have approached to further optimize the system. Rather than hitting the DB with each iteration, I can decide what products go in my package, how my packages are most optimally split, and then invoke the shipAPI.

Installation

1. Hosted my DB on ElephantSQL, you can connect in your terminal using the command

psql postgres:ekwmfpwq:[e-mail]:5432/ekwmfpwq;

2. The catalog DB has already initially been populated with the data with Qty 0

3. If you would like to run through the process, please manually add qty to the product_id of the catalog. Ideally, process_restock would have adding the qty to the catalog table.

4. Send an order in and you should see the shipments table populate based on the packages that get sent