Mandarin-speaking: Customer Success Engineer (Contract)

Retell AI is using first-principles thinking to reimagine the call center with cutting-edge voice AI. Thousands of companies now use 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've scaled to $80M in ARR with a team of 50, up from $5M at the start of 2025, and are now valued at over $1.5B.

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 act as frontline agents, QA analysts, and managers, continuously executing, monitoring, and improving every customer interaction.

We're growing fast and looking for ambitious builders who want to tackle hard technical problems, move quickly, and have a real impact on one of the fastest-growing voice AI companies in the world.

Let's build the future together.

Recent recognition:

• No. 1 Best Places to Work in the Bay Area, San Francisco Business Times 2026

• Top 50 AI Apps, a16z (2025)

• #3 Fastest-Growing Software Company, G2 Best Software Awards 2026

• Best Agentic AI Software, G2 Best Software Awards 2026

• #4 Fastest-Growing Software Vendor, Brex Benchmark 2025

• Enterprise Tech 30 Class of 2026, Nasdaq & Wing VC

• Top-Ranked Startup, Lean AI Leaderboard

• Backed by Y Combinator

We're hiring a Mandarin-Speaking Customer Success Engineer on a long-term 1099 contract to help enterprise customers successfully deploy and scale AI voice agents in production.

You'll work directly with customers to build AI voice agents, design integrations, troubleshoot deployments, and solve technical problems. The 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 technical teams.

• Support technical onboarding and deployment for enterprise customers.

• Help customers launch and scale AI voice agents.

• Build trusted relationships with customer engineering teams.

• Build AI voice agents alongside customers.

• Design conversation flows and deployment strategies.

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

• Troubleshoot production deployments and technical issues.

• Work directly in customer codebases when needed.

• Identify product gaps through customer feedback.

• Translate customer needs into actionable product improvements.

• Work closely with Product and Engineering teams.

• Help customers launch new AI use cases.

• Identify opportunities to expand product adoption.

• Become a trusted technical partner to enterprise customers.

• Must be able to read, write, and speak in Mandarin and English.

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

• 2-8 years of professional software engineering experience, with a strong backend focus (e.g., building and maintaining services, APIs, and data pipelines in production). Prior Solutions Engineering, Forward Deployed Engineering, or Customer Success Engineering experience is a plus, but a software engineering foundation is required.

• Strong backend fundamentals: you can write clean, working code on your own (Python, Node.js, or similar), design and integrate REST/webhook APIs, work with databases, and reason about system design, authentication, and error handling.

• Able to pass a hands-on backend technical assessment (live coding or take-home) without relying on AI tools. We expect you to use AI to move faster, but you must understand and be able to explain, debug, and fix the code yourself.

• Proven ability to debug complex issues across systems by reading logs, tracing requests, and isolating root causes in customer integrations.

• Excellent communication skills: you can explain technical concepts clearly to both engineers and non-technical stakeholders, and work directly with customers to scope and build solutions with them.

• Must be available to work some overlapping hours with our Pacific Time-based team and customers.

• Experience with AI, LLMs, or Voice AI.

• Startup experience.

• Enterprise customer experience.

• Willingness to travel occasionally for customer launches or onsite work.

• You enjoy solving technical problems directly with customers.

• You like building alongside customers rather than just supporting them.

• You're comfortable debugging complex systems.

• You move quickly and enjoy a fast-paced startup environment.

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

• Employment Type: Full-Time 1099 Contractor

• Location: Remote

• Compensation: $6000–$7500 USD/Month, based on experience

• Hours: Must be open to working some overlapping hours with our Pacific Time team and customers.