We had 1 Android app to be developed for charity org for data collection for ground water level increase competition among villages.

Initial scope was very small & feasible. Around 10 forms with 3-4 fields in each to be developed in 2 months (1 for dev, 1 for testing). There was a prod version which had similar forms with no validations etc.

We had received prod source, which was total junk. No KT was given.

In existing source, spelling mistakes were there in the era of spell/grammar checking tools.

There were rural names of classes, variables in regional language in English letters & that regional language is somewhat known to some developers but even they don't know those rural names' meanings. This costed us at great length in visualizing data flow between entities. Even Google translate wasn't reliable for this language due to low Internet penetration in that language region.

OOP wasn't followed, so at 10 places exact same code exists. If error or bug needed to be fixed it had to be fixed at all those 10 places.

No foreign key relationships was there in database while actually there were logical relations among different entites.

No created, updated timestamps in records at app side to have audit trail.

Small part of that existing source was quite good with Fragments, MVP etc. while other part was ancient Activities with business logic.

We have to support Android 4.0 to 9.0 of many screen sizes & resolutions without any target devices issued to us by the client.

Then Corona lockdown happened & during that suddenly client side professionals became over efficient.

Client started adding requirements like very complex validation which has inter-entity dependencies. Then they started filing bugs from prod version on us.

Let's come to the developers' expertise,
2 developers with 8+ years of experience & they're not knowing how to resolve conflicts in git merge which were created by them only due to not following git best practice for coding like only appending new implementation in existing classes for easy auto merge etc.

They are thinking like handling click events is called development.

They don't want to think about OOP, well structured code. They don't want to re-use code mostly & when they copy paste, they think it's called re-use.

They wanted to follow old school Java development in memory scarce Android app life cycle in end user phone. They don't understand memory leaks, even though it's pin pointed by memory leak detection tools (Leak canary etc.).

Now 3.5 months are over, that competition was called off for this year due to Corona & development is still ongoing.

We are nowhere close to completion even for initial internal QA round.

On top of this, nothing is billable so it's like financial suicide.

Remember whatever said here is only 10% of what is faced.

- An Engineering lead in a half billion dollar company.