Five9 is a leading cloud contact-center (CCaaS) provider — handles inbound/outbound/blended call center workloads with AI agent assist. Public since 2014. The interview emphasizes real-time voice infrastructure, ACD/IVR design, and the AI/ML used for routing, transcription, and agent assist.
Process
Recruiter screen → 60-minute coding phone (DSA medium) → onsite virtual: 2 coding, 1 system design, 1 craft deep-dive, 1 behavioral. Cycle: 3–5 weeks.
What they actually ask
- Design an automatic call distributor (ACD) at scale
- Design an IVR with low-latency speech recognition
- Design real-time agent-assist using LLMs
- Coding: medium DSA, often with concurrency or queue framing
- Behavioral: ownership, on-call discipline, customer empathy
Levels and comp (2026)
- SE II: $130K–$165K total
- Senior SE: $190K–$250K
- Staff: $270K–$365K
- Principal: $385K–$510K
Prep priorities
- Be fluent in Java or Go (most of the platform)
- Understand SIP/RTP, WebRTC, and ASR/TTS pipelines
- Brush up on contact-center concepts (ACD, IVR, blended dialers)
Frequently Asked Questions
Is Five9 remote-friendly?
Hybrid in San Ramon CA (HQ), Atlanta, San Jose. Many engineering roles fully remote within US.
How does Five9 compare to NICE or Genesys?
Genesys is the largest by enterprise share. NICE has the broader CX-suite. Five9 is the AI-forward mid-market leader. Comp is mid-tier; below cloud leaders.
What is the engineering culture?
Mature, customer-driven, calmer pace. Strong work-life balance.