Five9

Senior Staff Engineer, AI Agents

Five9

full-time

Posted on:

Location Type: Hybrid

Location: 🇺🇸 United States

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Salary

💰 $113,800 - $316,600 per year

Job Level

Senior

Tech Stack

AWSAzureCloudGoogle Cloud PlatformGRPCJavaMicroservicesOpen SourceSDLC

About the role

  • Responsible for the software architecture and software development of Five9’s AI Agent software platform.
  • Mentor junior engineers and set technology direction for platform.
  • Collaborate cross-functionally to ensure complete solutions are delivered.
  • Make important technology decisions and guide platform evolution.
  • Ensure that the software platform is scalable, reliable, observable, and maintainable.

Requirements

  • 1+ years of experience in software development for GenAI platforms for Customer Support/Customer Experience is REQUIRED.
  • 5+ years of software development experience in Java.
  • 5+ years of experience in enterprise SaaS software development.
  • 10+ years of software development experience.
  • Bachelor's or advanced degree in computer science, computer engineering or similar.
  • Expert-level proficiency in Java and JVM-based frameworks.
  • Strong understanding of object-oriented design, design patterns, clean code, refactoring, and code quality best practices.
  • Deep experience designing and building distributed, event-driven systems with high reliability and low latency.
  • Expertise in API design (REST/gRPC), service contracts, and backward-compatible evolution.
  • Strong familiarity with LLMs, prompt orchestration, function calling, and multi-agent reasoning workflows.
  • Experience building AI-enabled microservices, including integrating LLM providers, embeddings, vector databases, RAG pipelines, and structured output validation.
  • Solid understanding of model latency, throughput, caching strategies, eval frameworks, and ML-specific observability.
  • Experience using one or more frontier models from OpenAI, Google, or open source.
  • 5+ years experience in building enterprise SaaS software.
  • Expertise with public cloud software development platforms, AWS, GCP or Azure. Preference for GCP experience (Five9 is on GCP).
  • Strong familiarity with networking fundamentals: HTTP/2/3, gRPC, load balancing, API gateways, service meshes.
  • Strong command of SRE principles: SLIs/SLOs, error budgets, incident response, root cause analysis.
  • On-call experience, including incident handling, troubleshooting, and service remediation.
  • Experience designing systems for observability: tracing, logging, metrics, profiling.
  • Knowledge of performance optimization—CPU, memory, threading, concurrency, GC tuning.
  • Hands-on experience running 24×7 global enterprise SaaS systems in production.
  • Familiarity with authentication/authorization technologies (OAuth2/OIDC, JWT, mTLS).
  • Understanding of secure coding practices, data protection, and enterprise SaaS compliance needs (SOC2, GDPR, HIPAA).
  • Ability to drive end-to-end architecture for complex platforms, from requirements → design → implementation → deployment.
  • Ability to mentor and elevate teams—code reviews, design guidance, pairing, coaching junior engineers.
  • Strong communication skills; capable of explaining technical decisions to Engineering leadership, Product & UX, Support, SRE, QA, and Solutions Engineering.
  • Demonstrated ability to collaborate across orgs to deliver complete, integrated product experiences.
  • Ability to set technical direction for the platform and influence roadmaps.
  • Ownership mentality across the entire SDLC—design → implementation → CI/CD → monitoring → production operations.
  • Exceptional judgment in balancing innovation vs reliability, short-term velocity vs long-term maintainability.
Benefits
  • Health, dental, and vision coverage, beginning on the first day of employment. Five9 covers 100% of the employee portion of the health, dental and vision coverage and shares a high portion of the dependent cost. We also offer Short & Long-Term Disability, Basic Life Insurance, and a 401k saving plan with employer matching.
  • Access to an innovative mental health support platform that offers personalized care and resources in areas such as: therapy, coaching and self-guided mindfulness exercises for all covered employees and their covered dependents.
  • Generous employee stock purchase plan.
  • Paid Time Off, Company paid holidays, paid volunteer hours and 12 weeks paid parental leave.

Applicant Tracking System Keywords

Tip: use these terms in your resume and cover letter to boost ATS matches.

Hard skills
JavaJVM-based frameworksobject-oriented designdesign patternsAPI designevent-driven systemsAI-enabled microservicesperformance optimizationSRE principlessecure coding practices
Soft skills
mentoringcollaborationcommunicationtechnical directionownership mentalityjudgmentcoachingdesign guidancetroubleshootingincident handling