I half expect a comment here explaining why Gitlab does it better ;)
We're struggling with our load balancers right now. We're using Azure load balancers and then HAproxy. But the Azure ones sometimes don't work. Luckily the new network type on Azure supports floating IPs so we can set something up ourselves https://gitlab.com/gitlab-com/infrastructure/issues/466
The one about the load balancer is https://gitlab.com/gitlab-com/infrastructure/issues/467 but we don't have a lot of data published just yet as we are currently figuring it out.