Senior Software Engineer, Backend (AI Agent Integrations)

Cresta unlocks the true potential of the customer experience, turning every conversation into a competitive advantage. Cresta’s unified AI platform combines conversational AI agents, real-time human agent augmentation, and comprehensive conversation intelligence to drive revenue and efficiency gains across every channel. The world’s leading companies, including United Airlines, Cox Communications, and Marriott, use Cresta to power world-class customer experiences every day. Born from the Stanford AI Lab, Cresta has raised more than $270 million from the world’s leading investors, including a16z, Greylock, and Sequoia. Cresta’s leadership includes some of the leading minds in AI today. Our CEO, Ping Wu , founded and led Google's Contact Center AI and Vertex AI platforms before joining Cresta to build the future of AI-driven customer experiences. Over the next few years, AI is going to redefine how people all over the world interact with businesses every day. Come build that future at Cresta. About the role: Cresta’s AI Agent team is building enterprise-grade AI Agents that can operate inside real-world contact center environments. A critical part of that mission is enabling our AI Agents to seamlessly integrate with customers’ CCaaS platforms (Contact Center as a Service), including voice and digital channels — and to smoothly transition conversations between AI and human agents when needed. This role is focused on building the backend systems that allow our AI Agents to: • Integrate deeply with leading CCaaS platforms • Participate in live customer conversations across voice and chat • Maintain full conversation state and context • Perform real-time actions within the CCaaS ecosystem • Seamlessly hand off conversations to human agents — without losing context, history, or workflow state • Support human agents with AI assistance after transfer We are looking for strong backend engineers who want to work at the intersection of distributed systems, real-time communication, enterprise integrations, and AI Agent orchestration. This is not a pure research role — it is about building production-grade infrastructure that enables AI Agents to operate reliably in mission-critical customer environments. Why This Role Is Unique: • AI + Real-Time Systems : Work on infrastructure that enables AI Agents to participate in live conversations at scale. • Enterprise-Grade Integrations : Design robust integrations with major CCaaS platforms and customer systems. • Human-AI Collaboration : Build the systems that make AI-to-human handoff seamless, contextual, and reliable. • High-Impact Engineering : Your work directly determines how smoothly AI Agents operate in production environments. If you’re a strong backend engineer who wants to apply your expertise to real-world AI systems operating inside complex enterprise ecosystems, this role offers that opportunity. Responsibilities : • Design and build scalable backend services that integrate Cresta’s AI Agents with customers’ CCaaS platforms. • Architect systems that manage real-time conversation state, context propagation, and session lifecycle. • Implement seamless AI-to-human handoff mechanisms, ensuring full context transfer and minimal disruption to the customer experience. • Develop secure and reliable integrations with CCaaS APIs (voice, chat, messaging, routing, agent desktop, etc.). • Collaborate closely with ML engineers and AI researchers to operationalize AI Agent capabilities in live environments. • Ensure high availability, low latency, and strong observability for real-time conversation systems. • Implement authentication, authorization, compliance, and enterprise security best practices across integrations. • Drive improvements in reliability, performance, and