I'm slated to work on a pretty big project, and because of this, there are 2 other engineers to help out on it, both of them more senior than me. I've broken up the project, and at a very high-level, there's 2 types of work:
This leaves me with the following crossroads as a lead on this project:
Any thoughts on which of the 2 paths I should take?
My advice is work backwards from what you need to do and figure out the priorities accordingly. For example, let's say this is a mission-critical project with a tight deadline - It's probably better to do option #2 and delegate the work to de-risk the project and increase velocity. However, if the timeline is more flexible, then it's possible doing option #1 makes more sense.
That being said, I do want to push back a little bit on the mentality with option #1 since it's something I've seen with many mid-level engineers in particular looking for a senior promotion. There are ways to show senior engineer behavior besides technical scope. I have also found that focusing a lot on technical scope leads to this more "zero-sum" mentality, which can be counterproductive as your mentality now isn't as well geared towards expanding/creating scope, treating scope as this finite resource that needs to be "claimed" instead.
As a senior engineer, you are responsible for the overall delivery of a project. This means that your mentality should always be to "fill in the gaps", doing whatever it takes to make sure that the project crosses the finish line. This will often times involve non-coding work like:
You can also add a lot of technical value (i.e. show a lot of senior engineer technical depth) if you were to delegate these tasks away and not code them yourself. Here's some ideas on how to that:
All that being said, I always recommend talking to your manager about situations like these. I have never worked at Twitter, so I don't have a deep understanding of what it values in a senior engineer (and this will often times vary by orgs within the same company). Your manager should have this context and give a well-informed recommendation accordingly.