Retell is building the new standard for automating call center communications, including sales, support, customer engagement, and retention calls.

Backed by Altman Capital, Y Combinator, and top investors, we've raised a $4.7M seed round and hit $14M ARR in 15 months.

Check us out on the Top Lean AI Native Companies Leaderboard at leanaileaderboard.com.

As a Founding 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 You

• Have 2+ years of backend development experience with a degree in CS, CE, or EE.
• Take ownership like a founder, with a passion for impactful software.
• Thrive in fast-paced, ambiguous environments, solving new problems with curiosity.
• Communicate clearly, collaborate across teams, and drive momentum.
• Have startup experience or grit to adapt, with bonus points for cloud infra/DevOps knowledge.

Job Details

• Job Type: Full-time, 70 hr/week (50 hr/week onsite with flexible hours + 20 hr/week work from home)
• Cash: 215k - 290k
• Equity: 0.4 - 0.6%
• Location: Redwood City, CA, US
• US Visas: Sponsors Visa & Green Card

Other Benefits

• 100% medical, dental, vision insurance coverage
• Unlimited breakfast, lunch, dinner, and snacks
• Gym and daily commute fee reimbursement
• Internet and phone bills covered

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 high performers.
• High Ownership: Small teams, >$1M revenue/employee, and significant equity.
• Performance-Based: Offers tied to interview performance, not experience or past salaries.

Interview Process

1. Online Assessment (25–30 min): One HackerRank coding questions on practical problem-solving (7 days to complete).
2. Technical Phone Interview 1 (30 min): Live coding on CoderPad, focusing on data structures and algorithms.
3. Technical Phone Interview 2 (30–45 min): Deeper CoderPad session on algorithmic thinking and coding fluency.
4. Onsite/Virtual Interviews (2–3 hrs): Hosted in our office if located in the Bay Area or virtual, with three rounds:
   1. Practical Coding: Tackle real-world coding tasks with debugging in a basic environment set up like Python Flask or Node.js Express, etc.
   2. System Design: Architect a production-ready system.
   3. Tools & Automation: Build automations or improve workflows in any basic environment setup like Python Flask or Node.js Express, etc.