My First encounter with NullPointerException for live app on PlayStore.
I am a developer working on Android Platform for more than one year and during this time period I worked on many application for client. Almost everyday I spend my time chasing NullPointerException in the application code. Even after all the debugging and null check, there might be some conditions in the code that the QA team will find the bug with the NullPointer. I would test the condition and fixed the bug, but never paid much attention why Null References is a “The Billion Dollar Mistake” untill this happened to me.
I decided to lauch my own application on the play Store and started working on the app SIP Calculator for making calculations of Systematic Investment Plans easy. I found the already existing app lacks few features and doesn’t have very friendly UI/UX. I added few more features like specific news and information related to SIP and Mutual funds from various popular portals on the internet. I finished working on the app in one week launched after testing all the features in the app by my own.
I spread the words about the app with my friends and family and very soon I started getting user to the apps apart from friends and family members. My daily app download started increasing from 10 to 20 per day to 100, 200, and then 400 install each day. SIP calculator within one and half months reached 10,000 downloads, which made me very happy as this was my first app on the play store people started liking.
Then all of the sudden this happened which was totally unexpected and the impact was so huge on the app. As already mentioned I was serving the news and personalised articles about SIP on the main screen through the RESTFul API. I used Retrofit to fetch all the news from the server. Due to some reasons my friend redirected the domain name I was using in the app to another domain without informing me and the app started getting the NullPointerException because there was no response from the server. I was very busy with my daily schedule and didn’t get the time to check app and the developer console. After two days I checked the developer console and got quite surprised.
I got 4259% increase in the app crash.

115 % increase in the app uninstall.

I even got my first 3 star rating from the user.😞😞

SIP Calculator slipped to the search results to 10 from 4 number on play store after long time and number of download started decreasing gradually. Everthing happened so quickly that within only two day app perfromance on the play store became worst.
I fixed the NullPointer and fixed the URL redirection issue but all this left a huge impact on me.