Senior Software Engineer in AI - Java Spring, Backend

Senior Software Engineer in AI - Java Spring, backend

Five9 is a leading provider of cloud software for the enterprise contact center market, bringing the power of the cloud to thousands of customers and facilitating more than three billion customer interactions annually. Five9 has led the cloud revolution in contact centers, helping organizations transition from legacy premise-based solutions to the cloud. The cloud contact center market has become the hot space for innovation in real-time communications and is the tip of the spear for the application of Artificial Intelligence. Five9 has led the charge with its Genius AI platform. Five9 offers a high-energy environment with lots of room for personal and professional growth. Our innovative AI team is seeking a talented and experienced Senior Full Stack Software Engineer. In this role, you will be part of the team that builds software that brings AI technologies to users. Prior AI experience is not required - you will have the opportunity to integrate with AI technologies from vendors like Azure, OpenAI, Google, Databricks, IBM, and Amazon, and thus receive on-the-job experience for some of the hottest skills on the market. An ideal candidate for us is an experienced engineer who is passionate about building high performance web platforms and applications, a brilliant problem solver and a creative self-starter.

Key Responsibilities:

• Be part of an agile team developing a scalable, highly available application platform using modern PaaS platforms such as GCP.
• Utilizing Java Spring Framework, Spring Boot and reactive programming pattern for creation of highly scalable, robust microservices.
• Participate and contribute to requirements analysis and feature grooming.
• Understand how to leverage PaaS components, such as message buses, cloud functions (lambdas), and noSQL databases when developing software in order to achieve scalability, reliability, and operability.
• End-to-end feature development from UI implementation all the way through the middleware and backend platform.
• Document and communicate clearly architecture and implementation solutions.
• Have ownership of your code in production, including on-call, troubleshooting.

Key Skills:

• 5+ years software development experience.
• Highly proficient in Java – Spring Framework, Spring Boot, reactive programming (desirably, but not required to have experience with rxjava or similar) and JavaScript.
• Experience with PaaS hosted relational and no-SQL databases (mySQL, BigQuery, DataStore, etc)
• Familiarity with vibe coding using different AI tools like Claud Code,
• Experience in developing automated test cases with modern tools such as Junit.
• Experience in operational code ownership – on-call, troubleshooting, uptime.
• Experience in applying design patterns and separating concerns in a distributed system.
• Experience with Web Technologies (HTML, CSS, DOM, JavaScript) and web standards (HTML5)
• Familiarity with client-side JavaScript Toolkits such as React is a plus but not required.
• Must have experience working within an Agile/Scrum team.
• Positive, self-motivated and enthusiastic attitude with a strong sense of ownership.
• Strong proactive communication skills, both verbal and written.
• Design and manage data pipelines to process AI-generated insights, ensuring reliable data flow, quality, and actionable outputs for decision-making.
• AI skills in speech recognition and natural language processing are a plus but not required.
• Experience in contact center software is a plus but not required.