Defines what we call the Infobip platform - standardized way of how our micro-services are structured, controlled and monitored, how they communicate (RPC) and how the load balancing works. For load balancing we use either external network balancers (HAProxy) or client-side balancing implemented within the services. Core software platform also provides our CI/CD pipeline - fully automated process of how source code is built and tested, how applications are compiled and packaged and how they are deployed to production. Platform layer tools allow us to have visibility and control over all our services. Platform teams also develop some core services that provide common functionalities like authentication/authorization and exposing services on Infobip's external APIs. Platform teams also develop a number of standard libraries and helper proxies that are used by Infobip services.
Our Core software platform layer is maintained by PaaS (Platform as a Service) teams. The goal of this layer is to make life of developers easier, providing common tools and out-of-the-box functionalities so that developers can focus on solving business problems instead of thinking about how to solve usual infrastructure problems.
Our services can be built in various technologies, as long as they conform to our platform contract, but one could say that Infobip is primarily JVM based company. Most of the core backend services are written in Java or Kotlin, but there is also a large .NET community. There are other tech stacks in use like Golang (primarily for infrastructure) and Python / Groovy / Ruby / Bash / Powershell used mostly for scripting and automation. We do not restrict our developers from using any technology that solves business problems.
Observability tools - monitoring (Prometheus, New Relic), logging (Graylog) and alerting (Opsgenie) are provided by Quality part of this layer. Those tools are in large part automatically configured for each new developed service, so the developers can easily create dashboards and configure metrics and alerts for our new products.