Senior Software Engineer, Backend

ABOUT RETELL AI

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.

ABOUT THE ROLE

As a Senior Backend Engineer, you’ll shape the core systems powering millions of AI-driven conversations. You’ll tackle real-time audio, global telephony, and developer tooling, working across the stack with the founding team. This high-impact role offers rapid feedback loops, customer collaboration, and the chance to define a category-leading product.

KEY RESPONSIBILITIES

• Build foundational architecture for Retell's platform, such as prompt orchestration, testing frameworks, observability dashboards, and telephony integrations.
• Design scalable backend systems and DevOps workflows for reliable performance across millions of calls.
• Lead complex projects from architecture to production, driving delivery and monitoring.
• Collaborate with product and design teams to create intuitive APIs and interfaces for quick customer onboarding.
• Support customer onboarding, troubleshoot issues, and turn feedback into product improvements.

YOU MIGHT THRIVE IF

• Have 2+ years of backend development experience and a strong foundation in CS fundamentals (CS/CE/EE degree or equivalent).
• Have worked on scalable, high-performance backend systems, especially anything involving concurrency, data, storage, or distributed components.
• Take ownership like a founder and enjoy building core systems that need to be fast, reliable, and correct.
• Thrive in fast-moving, ambiguous environments where you learn quickly and solve new technical problems.
• Communicate clearly, collaborate well across teams, and move work forward with momentum.
• Have startup experience or the grit to operate in a high-velocity environment, bonus points if you’ve worked on infrastructure, databases, or large-scale backend systems.

JOB DETAILS

• Cash: 200k - 300k
• Equity: Offer Equity
• Location: Redwood City, CA, US
• US Visas: Retell AI is open to sponsoring work authorization for qualified candidates, including H-1B, TN, L-1, E-3, F-1 (OPT/CPT), and O-1 visas.

OTHER BENEFITS

• 100% coverage for medical, dental, and vision insurance
• $70/day DoorDash credit for unlimited breakfast, lunch, dinner, and snacks
• $200/month wellness reimbursement (gym, fitness classes, etc.)
• $300/month commuter reimbursement (gas, Caltrain, etc.)
• $75/month phone bill reimbursement
• $50/month internet reimbursement

COMPENSATION PHILOSOPHY

• Best Offer Upfront: Choose from three cash-equity balance options; no negotiation needed.
• Top 1% Talent: Above-market pay (top 5 percentile) to attract exceptional builders.
• High Ownership: Small teams, >$1M revenue/employee, and significant equity.
• Performance-Based: Offers tied to interview performance, not experience or past salaries.

INTERVIEW PROCESS

• Intro Call (15-20min): Connect with our Recruiter to get a deeper look at the team and the work you'd be doing.
• Technical Interview (45 min): Practical coding session focused on code fluency and system design (For frontend roles, we will focus on React-specific questions. For backend roles, we take a technology-agnostic approach.)
• Technical Interview (45 min): A system design-focused interview assesses your knowledge of building product-ready systems.
• Onsite/Virtual Interviews (2–3 hrs): Hosted in our office if located in the Bay Area or virtual, with three rounds:
• Practical Coding: Tackle real-world coding tasks with debugging.
• System Design: Architect a production-ready system.
• Tools & Automation: Build automations or improve workflows in any basic environment setup like python, java, node.js, etc.

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