One of my core goals is to get to L5, which is senior at Target. However, I'm not entirely sure what is necessary to get to that next level - I've tried to get specifics from my manager, but their answers have been relatively vague. I was wondering if anyone could share more concrete attributes of what a strong senior engineer looks like.
Alex has a very good mid-level to senior growth plan that you can find in Slack (it's a fairly long PDF). Even with the description though, it may not be super actionable.
What I'd recommend is for you to propose a few projects and the scope of work, and then ask the concrete question "How do you think this work I have planned ladders up to a senior promotion in the next performance cycle?" (or w/e the timeline is)
A few of the points that stand out to me regarding what senior means:
I'd also ask questions about the different ways engineers at Target are assessed (e.g. mentorship, code velocity, direction-setting, etc).
Here's the growth plan Rahul alluded to. It is the growth plan that I shared with all my E4 (Meta mid-level) mentees to help them get to E5 (Meta senior-level). It's one of my proudest works and feedback around this document has been great, but there's a couple caveats using it for your situation:
On top of the Meta E4 -> E5 growth plan, I also heavily recommend this Q&A from a mid-level Microsoft engineer to understand what senior scope looks like: "How to identify projects that are more suitable for senior engineers?"
Going back to the original question, there's a lot to unpack here (the senior promotion is generally a tough one), so I'll just add something from my experience that I found useful in understanding what it means to be a senior engineer (with the definition I worked with across Meta and Robinhood).
I joined Instagram as a mid-level engineer. One piece of advice my 1st manager at IG gave me in helping me grow to senior is they told me to observe and learn from a stellar senior engineer on my team, who was an iOS tech lead. My manager told me that they could just give this iOS engineer a few sentences like "Allow advertisers to add a polling sticker to Instagram story ads", and this engineer would just "magically" handle it all without my manager having to worry. This means that this engineer would do things like:
They would do all of this with 0 hand-holding and essentially act as an "API" our manager could call to deliver a large month project end-to-end with our manager having peace of mind the entire time.
To me, that's what a competent senior engineer looks like: Someone who can take an extremely ambiguous 6-9 month project and deliver it all on-time and with high-quality as the primary leader.