Application from external vendor seen as a black sheep in team

Posted by Refmak@reddit | ExperiencedDevs | View on Reddit | 45 comments

My team has become responsible for an application from an external vendor, that we're now supposed to integrate into our own in-house application.

The caveat is that the application from the external vendor is both very antiquated, overly complex and somewhat lacking in documentation. On top of that, the external vendor is hard to work with and constantly trying to up-sell consultancy hours for their lack of documentation (lol).

As a result, the application from the external vendor has become the "black sheep" within the team, which no engineer wants to have anything to do with if they can avoid it. Instead, all focus is on the in-house application.

This makes the aforementioned integration difficult to design, since a big part of it is to properly understand the external applications APIs, which is a task no one wants to undertake - likely due to some level of fear of personal ownership (i.e. becoming the external vendor applications "support person" within the team).

It's become to the extend that engineers will pass off assumptions about what the applications APIs allow us to do as hard facts, both to business and to ourselves in-team, without doing any testing whether the assumptions are correct at all.

Because of this we keep running head-first into a wall when designing the integration. Basic restful API endpoints are assumed to function one way, and it's a coin toss if it really does until someone - usually me - gives in and tests it by spending 5 minutes just calling it using the open api specs.

How would you go about turning this team dynamic regarding the external application around, when it's so crucial for the success of this integration?