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
Retell AI transforms customer experience with voice AI for enterprises, including customers like CVS/Aetna, American Airlines, Lenovo, and Grab. We have more customer stories than we can tell!
We’re looking for a Principal/Staff Engineer to help own the technical direction of our core platform. This is a staff-level IC role for someone who thrives in ambiguity, moves fast, and raises the bar for everyone around them.
You’ll work across systems, infrastructure, and product surfaces partnering closely with engineering, product, and leadership to scale what’s already working and build what’s next.
This is not a “ticket taker” role. You’ll define problems, design solutions, and ship.
KEY RESPONSIBILITIESOwn the design and evolution of core platform and systems architecture.
Lead complex technical initiatives end-to-end, from concept to production.
Make high-leverage technical decisions that balance speed, reliability, and scale.
Raise the technical bar through design reviews, mentoring, and hands-on leadership.
Partner closely with product to translate business needs into robust technical solutions.
Identify and resolve performance, scalability, and reliability bottlenecks.
Help define engineering best practices as we scale the team and platform.
You have 9+ years of experience building and operating production systems.
You’ve operated at Staff or Principal level (or equivalent scope), even if the title wasn’t official.
You’re strong in systems design and can reason clearly about tradeoffs.
You move fast but care deeply about correctness, reliability, and maintainability.
You’re comfortable owning ambiguous problems and defining the path forward.
You’ve built or scaled platforms used by real customers at meaningful volume.
You enjoy being hands-on writing code, reviewing designs, and unblocking teams.
Bonus points if you’ve worked with: distributed systems, Voice AI, real-time systems, APIs at scale, infra/platform work, or developer-facing products.
WHY THIS ROLEReal ownership over core systems.
Direct influence on product and company direction.
A small, high-caliber team with very little process drag.
Problems that matter to customers, revenue, and scale.
If you want a role where your decisions visibly shape the company, this is it.
JOB DETAILSCash: $225-$350k
Equity: Offers Meaningful Equity
Location: Redwood City, CA, US (100% Relocation Provided)
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.
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
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
Recruiter Screen (15min): Speak with a member of the talent team to learn more about us and which team you would be a good fit for.
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): This is a systems design-focused interview. There will be no coding; we want to assess your skills in systems design.
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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