Software Engineer - Voice Platform

Sela AI; San Francisco (CA); Hybrid; USD 140,000 - 210,000; Full time

Benefits offered by this job

Health coverage

401(k) match

Unlimited PTO

Snacks & meals

Hybrid SF schedule

Job summary

Sela AI, the market-leading AI voice agent for mortgage lenders, is seeking a software engineer to own major components of its real-time voice platform, from architecture to production reliability.

You will improve voice performance, build observability tools, and integrate the voice stack with simulation systems, while training models for turn-taking and voicemail detection. Join a high-growth SF team building essential AI infrastructure.

Qualifications

• 3–6 years of software engineering experience.
• Experience building and operating low-latency, real-time, streaming, or distributed systems.
• Strong Python or Go skills and understanding of design patterns.
• Experience with instrumentation to diagnose latency, reliability, or quality issues.
• Experience using AI coding tools or agents to ship clean code.
• Experience in high-growth startups from Seed to Series B.

Responsibilities

• Own major components of Sela’s real-time voice platform, from architecture and implementation to reliability in production
• Improve voice performance across latency, audio quality, turn-taking, interruptions, transcription, and speech generation
• Build measurement, observability, and debugging tools to reproduce and diagnose voice issues
• Integrate our voice stack with simulation and evaluation systems, including end-to-end voice-to-voice evals
• Train, fine-tune, and deploy models for turn-taking, interruption handling, and voicemail detection
• Evaluate new voice models and providers, improving scalability, reliability, and cost efficiency of a platform handling hundreds of thousands of calls per day

Skills

Software engineering

Python

Go

Low-latency systems

Real-time / streaming systems

Instrumentation

AI coding tools

Startup experience

Job description

About Sela

Sela is the market-leading AI voice agent for mortgage lenders. Founded in 2024, we’ve grown like crazy (~$0->13M in 20 months), and currently count 5 of the 10 largest independent mortgage banks in the U.S. as enterprise customers. If we’re successful, the cost of owning a home in the US will become ~1% cheaper. We’ve raised $21M across our Seed and Series A from top investors.

Why this is a huge opportunity

Around 1% of the U.S. labor force works in phone sales, representing roughly $100B of annual salary, and the industry is poised at the brink of complete disruption. We are at the cutting edge of this economic transformation, one of the first companies creating real, durable economic value through applied AI.

Buying a house is the largest financial decision most people make in their lives, and homeownership is tied to many other purchases, including life insurance, homeowners insurance, alarm systems, home renovations, solar panels, and more. By owning the mortgage vertical, we will own the relationship with the consumer, allowing us to serve as the essential AI infrastructure for high consideration consumer sales.

Why Join

1. Crazy growth: The market pull is exhilarating - we’ve grown 10x in the past 12 months and more than 100x since our seed round, all without a dedicated sales or marketing team. Building something that people want so badly is the best feeling you can have in a startup.

2. Team and Culture: We are a high-agency team where the bar is high and everyone makes the people around them better. Collaboration and intensity are core team values: people truly care about their work and their coworkers. At the same time, we don't take ourselves too seriously.

3. Challenging problems: Outperforming human sales teams on half a million daily calls is not easy. Low-latency, real-time infra. 99.9% uptime. Enterprise-grade privacy and security. Advanced simulation and evaluation systems. Flexible A/B testing. AI scheduler and dialer. We own the whole stack and we do not compromise on quality.

4. Well-funded: We’ve raised $21M+ in total funding, most recently a $15M Series A in June 2026.

What will you do

• Own major components of Sela’s real-time voice platform, from architecture and implementation to reliability in production

• Improve voice performance across latency, audio quality, turn-taking, interruptions, transcription, and speech generation

• Build measurement, observability, and debugging tools that make complex voice issues easy to reproduce and diagnose

• Integrate our voice stack with simulation and evaluation systems, including end-to-end voice-to-voice evals

• Train, fine-tune, and deploy models for problems such as turn-taking, interruption handling, and voicemail detection

• Evaluate new voice models and providers, and improve the scalability, reliability, and cost efficiency of a platform handling hundreds of thousands of calls per day

What are we looking for

• 3–6 years of software engineering experience

• Experience building and operating low-latency, real-time, streaming, or distributed systems in production

• Strong Python or Go skills and a deep understanding of software design patterns and best practices

• Strong performance-engineering instincts and experience using instrumentation to diagnose latency, reliability, or quality issues

• Experience using AI coding tools or agents to ship maintainable, clean code

• Experience in high-growth startups, ideally at Seed through Series B

Benefits

• Top-of-market medical, dental, and vision coverage for you and your dependents

• 401(k) with a top-of-market employer match

• Unlimited PTO

• Snacks, weekly team lunches, and dinner on Sela

• Hybrid in-office schedule: four days a week together in SF, with a flexible remote day on Wednesdays