Staff 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 team 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. As a Staff Backend Engineer , you will lead the architecture and technical direction of Cresta’s AI Agent integration platform. You will define how our AI Agents connect to, operate within, and scale across complex enterprise ecosystems. 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 : This is a highly visible, high-impact role shaping the backbone of how AI Agents operate in mission-critical customer 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:  Lead the architecture and evolution of Cresta’s AI Agent integration framework across CCaaS platforms. Design scalable, extensible backend systems that manage real-time conversation state, session lifecycle, and context propagation. Establish architectural patterns for AI-to-human handoff that ensure durability, reliability, and seamless customer experience. Define integration strategies for voice, chat, messaging, routing, and agent desktop APIs across enterprise platforms. Drive system design for high availability, low latency, and fault tolerance in real-time environments. Set standards for observability, monitoring, incident response, and operational excellence. Partner closely with ML engineers to operationalize AI Agent capabilities into production-grade systems. Influence technical roadmap and prioritization in collaboration with engineering leadership. Mentor senior engineers and raise the bar for backend engineering excellence across the organization. Lead complex cross-team technical initiatives from design through production rollout. Qualifications We Value:  Bachelor’s degree in Computer Science or related field. 8+ years of experience building scalable backend systems in production environments. Demonstrated experience leading architecture for large-scale distributed systems. Deep expertise in API design (REST, gRPC) and service-oriented architectures. Strong understanding of real-time communication systems and low-latency system design. Experience designing integrations with third-party enterprise platforms and APIs. Proven track record of driving technical direction across teams. Experience with containerized environments (Kubernetes, Docker). Experience with cloud platforms such as AWS, GCP, or Azure. Strong expertise in reliability engineering, observability, and enterprise-grade security. Experience with CCaaS platforms, contact center systems, or real-time c