Customer Success Engineer

Retell AI is using first principles to reimagine the call center with cutting-edge voice AI.

Thousands of companies now utilize Retell's AI voice agents to handle sales, support, and logistics calls that once required large teams of human agents. Backed by Y Combinator, Alt Capital, and other leading investors, we have scaled to $80M ARR with a team of 50 people, up from $5M at the start of 2025.

Our vision for 2026 is to build a modern CX platform where entire contact centers are powered by AI. Instead of basic automation that needs constant human tuning, we're creating intelligent AI "workers" that can act as frontline agents, QA analysts, and managers, continuously executing, monitoring, and improving customer interactions.

We're growing quickly and looking for ambitious builders who want to tackle hard technical problems, move fast, and have real impact at one of the fastest-growing AI startups.

Let's build the future together.

• We're a top 50 AI app in the a16z list: https://tinyurl.com/5853dt2x

• #4 on Brex's Fast-Growing Software Vendors of 2025: https://www.brex.com/journal/brex-benchmark-december-2025

• Top Ranking Startup: https://leanaileaderboard.com/

• Enterprise Tech 30: https://www.wing.vc/et30/overview

Retell AI powers AI voice agents for enterprise contact centers. We work with customers like CVS/Aetna, American Airlines, Lenovo, and Grab, helping them automate millions of customer conversations.

We're hiring a Customer Success Engineer to help our enterprise customers successfully deploy and scale AI voice agents in production.

You'll become the technical partner for our customers, helping design integrations, troubleshoot deployments, build AI workflows, and ensure customers are successful from onboarding through expansion.

This role sits at the intersection of software engineering, customer success, and AI deployment. You'll work closely with Engineering, Product, and Customer Success while partnering directly with customer engineering teams.

This is a full-time, long-term W-2 contract position with the opportunity to make a significant impact at one of the fastest-growing AI companies. While the role is primarily based in our Redwood City office, we're open to remote candidates with strong Customer Success Engineering experience and exceptional technical backgrounds.

• Lead technical onboarding for enterprise customers.

• Become the primary technical point of contact throughout implementation.

• Drive successful customer launches and product adoption.

• Build trusted relationships with customer engineering teams.

• Build AI voice agents alongside customers.

• Design conversation flows and deployment strategies.

• Troubleshoot production deployments.

• Debug APIs, webhooks, SIP, telephony, authentication, integrations, and latency issues.

• Work directly inside customer codebases when necessary.

• Identify product gaps through customer feedback.

• Translate customer needs into actionable product improvements.

• Partner closely with Product and Engineering teams.

• Advocate for customers throughout the product development process.

• Identify expansion opportunities.

• Help customers launch new AI use cases.

• Increase product adoption across organizations.

• Become a trusted technical advisor for enterprise accounts.

• Bachelor's degree in Computer Science, Computer Engineering, Electrical Engineering, or a related technical field.

• One of the following:

  • 5+ years of experience in Customer Success or as a Customer Success Engineer at a B2B software company.

  • Recent graduate from a top-tier university with a degree in a relevant technical field.

• Strong technical problem-solving skills.

• Experience working with APIs and debugging technical issues.

• Excellent communication skills and the ability to explain technical concepts to customers.

• Working Hours: Must be available to work standard U.S. business hours in either the Pacific or Eastern Time zone, with sufficient overlap with Retell’s Pacific Time–based team and enterprise customers.

• Experience with Python or TypeScript.

• Experience working with AI, LLMs, or Voice AI.

• Startup experience.

• Experience supporting enterprise customers.

• Travel: Willingness to travel up to 10% for enterprise customer launches, onsite workshops, and customer Innovation Day events.

• You enjoy solving technical problems directly with customers.

• You like building alongside customers instead of just supporting them.

• You're comfortable debugging complex systems under pressure.

• You move quickly and enjoy working in fast-paced startup environments.

• You enjoy collaborating across Engineering, Product, and Customer Success.

• You care deeply about customer outcomes and shipping impactful solutions.

• Employment Type: Full-Time W-2 Contract (Long-Term)

• Location: Redwood City, CA (Onsite)

• Compensation: $65 - $75 hourly, based on experience

• Medical, dental, and vision insurance

• $70/day DoorDash credit for unlimited breakfast, lunch, dinner, and snacks (not included if remote)

• $200/month wellness reimbursement (gym, fitness classes, etc.)

• $300/month commuter reimbursement (gas, Caltrain, etc.)

• $75/month phone bill reimbursement

• $50/month internet reimbursement