Founding Senior Software Engineer (Backend) at Retell AI

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.

• 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.
• 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 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
• 100% medical, dental, vision insurance coverage
• Unlimited breakfast, lunch, dinner, and snacks
• Gym and daily commute fee reimbursement
• Internet and phone bills covered
• 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.
• Online Assessment (25–30 min): One HackerRank coding questions on practical problem-solving (7 days to complete).
• Technical Phone Interview 1 (30 min): Live coding on CoderPad, focusing on data structures and algorithms.
• Technical Phone Interview 2 (30–45 min): Deeper CoderPad session on algorithmic thinking and coding fluency.
• 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.
• Practical Coding: Tackle real-world coding tasks with debugging in a basic environment set up like Python Flask or Node.js Express, etc.
• System Design: Architect a production-ready system.
• Tools & Automation: Build automations or improve workflows in any basic environment setup like Python Flask or Node.js Express, etc.