Add Nikola Milojevic as backend maintainer (gitlab)

Trainee maintainer issue: #6189 (closed)

Overview

I've been a Senior Engineer on the Memory team since October 14th, 2019.

Since my joining the team and company, I have been working on the following things:

• Import/export - Worked on ndjson implementation and various performance fixes
• Refactored Gitlab::Metrics::Transaction
• Improving Blame, Blob Controller, and Markup performance
• N+1 SQL Cached queries, fixed some slowest endpoints, and improved Performance Bar to show cached queries as well.
• Introduced :until_executed deduplication strategy
• Introduced query caching for LoadBalancer, resulting in 10% reduction in TPS across the fleet
• Dynamic image scaling

I have also been a database reviewer for several months now.

Some contribution related stats (authored + reviewed MRs):

• Total: 75 merged MRs, 88 reviewed.
• gitlab: 63

Examples of reviews

• gitlab-org/gitlab!51660 (merged) - Catched few issues, and prposed to better organize the code, especially EE classes
• gitlab-org/gitlab!32111 (merged) - Interesting review, had a lot of suggestions
• gitlab-org/gitlab!32605 (merged) - really interesting discussion about using more general way to use Prometheus metrics for transactions

Things to improve

The memory team is kinda specific, we spend a lot of time in analyzing and measuring application performance, our MR throughput might lag behind that of product teams, and we do not work on a specific set of features in Gitlab.

• This means that we don't build a specific domain knowledge, but we do get exposure to a lot of different aspects of the entire GitLab stack.
• Frontend - we are more exposed to some low-level kind of work, such as how loadbalancer is working, and measuring RSS, USS and GC.stats, then ERB view rendering. But again, I spend lot of time improving performance of our Banzai::Filter::ReferenceFilter
• I am still concerned that I don’t have the full context of the code and that I may miss something

I believe that these things will get better in time, by reviewing more MRs, and working on the next thing that needs to be investigated and improved 😄

@gitlab-org/maintainers/rails-backend please chime in below with your thoughts, and approve this MR if you agree.

Developer checklist

• Before this MR is merged
  • Mention @gitlab-org/maintainers/rails-backend, if not done (this issue template should do this automatically)
  • Assign this issue to your manager
• After this MR is merged
  • Request a maintainer from the #backend_maintainers Slack channel to add you as an Owner to gitlab-org/maintainers/rails-backend
  • Consider adding 'backend maintainer' to your Slack notification keywords

Manager checklist

• Before this MR is merged
  • The MR has been open for 5 working days
  • More than half of the existing maintainers approve the MR
  • There are no blocking concerns raised (if there are, please follow https://about.gitlab.com/handbook/engineering/workflow/code-review/#how-to-become-a-project-maintainer)
• After this MR is merged
  • Announce the good news in the relevant channels listed in https://about.gitlab.com/handbook/engineering/#keeping-yourself-informed