Senior Software Engineer, Backend - Platform Team

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 Core Platform underpins the company’s entire product portfolio. Our long term vision is to build a robust, reliable, secure, and extensible foundation that supports continued innovation, satisfies enterprise customer requirements, and keeps operational costs in check. Two critical components for that are agent assist backend services and scalable authentication systems, tools, processes and frameworks based on industry standards and security best practices. This role is focused on building various backend systems needed to enable successful customer integrations: Enable agent assist integration for chat and email. This involves working with the frontend platform team, ML teams, infra team and other backend services. Expand our backend agent assist services to meet customer requirements and feature requests. Address any customer issues that block integrations, affect user experience or system performance. Work with the auth and security team to meet Cresta’s diverse authentication and security needs for internal workflows and external customer facing integrations. We are looking for strong versatile backend engineers who want to work at the intersection of distributed systems, real-time communication, enterprise integrations, and IAM systems. Why This Role Is Unique: Enterprise-Grade Integrations : Design robust integrations with major CCaaS platforms and customer systems. Specialized Auth Experience : Join the Cresta auth team and help build specialized authentication systems to authenticate users, service accounts, virtual agents, server workloads, cloud based authentication for external integrations, etc. Agent Assist Integrations : Work directly with the frontend platform team to build solutions for agent assist integrations for various channels such as chat and email and help rollout these integrations in 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, and expand your expertise in auth, this role offers that opportunity. Responsibilities : Contribute to building the best-in-class company in addition to building the best-in-class product. Architect systems that manage real-time conversation state, context propagation, and session lifecycle. Play a substantial role in the agent assist integration process (chat and email) and authentication engineering team. Work with Cresta product and engineering teams, build and continuously improve the Cresta platform and new product requirements. Stay closely with customers and their requirements, analyze the technical tradeoffs, own the customer facing deliverables. Demonstrate the engineering best practices in deliverables and daily work. Uphold others to the same high standards. Technical ownership in a substantial part of the Cresta authentication stack. 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 scalability in production environments handling high interaction volumes Qualifications We Value: Bachelor’s degree in Computer Science or related field. 5+ years of experience building scalable backend systems in production environments. Strong experience designing and maintaining robust APIs (REST, gRPC). Solid understanding of distributed systems and real-time communication architectures. Experience integrating with third-party enterprise platforms and APIs. Experience working with CCaaS platforms or contact center systems is a strong plus. Familiarity with AI Agents, Virtual Agents, or LLM-based systems is a plus. Experience with containerized environments (Kubernetes, Docker). Experience with cloud platforms such as AWS, GCP, or Azure. Strong understanding of system reliability, observability, and security in enterprise en