You may be already aware that ExpressRoute implements a dedicated connection between your on-premises environment and Microsoft cloud services – Office 365 or Azure.
While most of the Azure services (SQL instance,storage, VM…) were already able to be accessed using ExpressRoute, this was not the case for DevOps (https://dev.azure.com/ or https://{organization}.visualstudio.com).
Well, this is not the case anymore; since Oct 23rd 2018, you can access your DevOps services through ExpressRoute.
If you selected specific community/ies in your ExpressRoute configuration and want to add this capability you need to add the BGP community using the value of 12076:5050 (see https://docs.microsoft.com/en-us/azure/expressroute/how-to-routefilter-portal for how to configure route filtering or https://docs.microsoft.com/en-us/azure/expressroute/expressroute-routing#bgp for the BGP communities)