Support 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 grown 20x from $5M to $100M+ in annualized revenue run rate in under two years, reaching a $1.5B+ valuation.

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:

• Voice AI Startup Hits $100 Million Run Rate With $4.6 Million Funding

• Retell ranked #1 in G2 Voice AI evaluation

• 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

You’ll be the technical partner enterprise customers lean on to get voice agents live and keep them working. You’ll build alongside customer engineering teams, debug production issues, and turn what you learn into product improvements. If you like being in the room when a customer’s agent takes its first real call, and you can trace a dropped call through telephony, webhooks, and the LLM, this role is for you.

You’ll work with Engineering, Product, and Customer Success, and with customer developers, IT teams, and telephony providers.

Get enterprise customers live and scaling

• Lead technical onboarding for enterprise accounts, from kickoff and architecture review through go-live and ramp.

• Help customers move from pilot to production, including concurrency planning, load readiness, and rollout strategy.

• Build trusted relationships with customer engineering, IT, and security teams.

Build with customers

• Build voice agents with customers in Retell: prompts, conversation flows, knowledge bases, voice and language settings, and call transfer.

• Design integrations with customer systems such as CRMs, scheduling tools, ticketing, and internal APIs, using custom functions, webhooks, and the Retell API and SDKs.

• Advise on conversation design and deployment strategy for new use cases such as inbound support, outbound campaigns, appointment booking, and qualification.

• Work directly in customer codebases when needed.

Debug and resolve production issues

• Troubleshoot live deployments: call quality, latency, interruptions and turn-taking, transcription errors, hallucinations, tool-call failures, and unexpected agent behavior.

• Debug APIs, webhooks, authentication, SIP trunking and telephony (carrier setup, number routing, call transfers, caller ID), and custom LLM integrations.

• Use call logs, transcripts, and post-call analysis to find root causes, then write clear post-incident summaries for customers.

• Escalate to Engineering with reproducible cases and the context needed to fix issues fast.

Shape the product

• Capture customer feedback and turn it into specific, prioritized product requests.

• Spot repeated issues and write the docs, templates, and playbooks that stop them from recurring.

• Work with Product and Engineering to test new features with real customers.

Must have

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

• 2-8 years of professional experience in Technical Support Engineering, Customer Success Engineering, Solutions Engineering, Forward Deployed Engineering, Software Engineering, or a similar technical role.

• Strong technical problem-solving skills and comfort debugging distributed systems.

• Hands-on experience writing code, debugging APIs, and a deep understanding of versioning and code review process and best practices.

• Clear communication: you can explain a technical issue to a developer and to a business stakeholder, in writing and live.

• Comfort working directly with customers, including during live launches and incidents.

• Availability for meaningful overlap with Pacific Time working hours.

Nice to have

• Python or TypeScript experience.

• Experience with LLMs, prompt engineering, or voice AI and conversational AI platforms.

• Telephony knowledge: SIP, VoIP, PSTN, and providers like Twilio or Telnyx.

• Familiarity with latency optimization, speech-to-text and text-to-speech, or real-time (WebSocket) systems.

• Startup experience and enterprise customer experience, including security reviews and compliance questions (SOC 2, HIPAA).

You might thrive here if

• You’d rather build with customers than hand them a ticket response.

• You stay calm when a production call flow breaks and you enjoy tracing the cause.

• You’re curious about how AI voice agents work and can tell when the problem is the prompt, the integration, the carrier, or the platform.

• You move fast, take ownership, and are comfortable in an early-stage environment with a lot of ambiguity.

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

• Employment type: Full-time 1099 contractor

• Location: Remote

• Compensation: $5,250-7,500 USD/month, based on experience and location

• Hours: Some overlap with our Pacific Time team and customers is required