Java backend engineers. Both kinds of company here run large backends shared by many customers at once. For the messaging platforms, like Vonage and ValueFirst, that means the gateway that receives a customer's request, the routing of each message to the right mobile operator, delivery reports and usage billing. For the cloud phone systems it means the services that manage phone numbers, route calls, record them and keep customer accounts. This is the largest role, and the postings require Java and Spring Boot with Kafka, Kubernetes and AWS, the usual stack of a backend that handles a constant stream of events.

Frontend engineers. A cloud phone system is something an office uses all day. People see the softphone on their laptop, the meetings and chat window, and the console where an administrator manages phone lines and users. That makes frontend engineering the clearest signature of this Industry Vertical, hired here several times as often, relative to all hiring, as at a typical product company. React and TypeScript lead, with Vue at some companies. Many of these postings require WebRTC, the browser technology that carries live voice and video, and that is what sets this frontend work apart from ordinary web screens.

Test engineers. Testing has a larger place here than at most product companies. Testers automate checks of the cloud phone apps and the services behind them, in Java with Playwright, Selenium and Cypress, and they load-test message delivery.

Full-stack engineers. A small group on the cloud phone side works across a React front end and a backend written in whatever language the company uses, including Ruby on Rails.

C/C++ systems engineers on Linux. This was once the core engineering of business telephony. These engineers write call control, SIP (the protocol that sets up internet calls) and the media path that carries the audio, in C/C++ on Linux. Today they are a small group, found at the older phone-system makers, Avaya and Mitel, and at the API platforms that run their own voice networks, like Vonage and Telnyx, because the phone system has moved into cloud software.

Speech and voice-AI model engineers. A handful of engineers train and adapt speech recognition and spoken-language models for voice bots and call transcription, in Python and PyTorch with Transformers. For an industry this small, that is a notable concentration.

GenAI engineers. There are fewer than the industry's direction would suggest. The cloud phone companies, like RingCentral, Dialpad and Nextiva, compete on the transcript and summary that arrive with every call, but in India that shows up in hiring only lightly. Postings here require skills with large language models less often than at other product companies.

Cloud and DevOps engineers. A modest group runs the voice and messaging services across many regions, on AWS and Kubernetes with Terraform and Grafana.

Also present in small numbers. Go and Node backend engineers work on the newer messaging and API services, and Python engineers on the backends of voice bots.

Rare here. Data engineering, .NET, mobile, Software Engineer, Security roles, SAP and ServiceNow barely appear. Salesforce work does appear, but it is the companies' own customer-management system and back office, not what they build.