Staff ML Engineer - Voice AI

Toast Tab, Inc.; United States; On-site; USD 155,000 - 248,000; Full time

Job summary

Toast is seeking a Staff Machine Learning Engineer to enhance its platform with Voice AI capabilities. The role requires collaboration with engineers and data scientists to develop innovative voice solutions, deploy them at scale, and ensure optimal performance across multiple products. Candidates should have extensive experience in machine learning and voice technologies.

Benefits

Competitive compensation and benefits

Flexibility to meet changing needs

Hybrid work model

Qualifications

• 7+ years of ML software development experience.
• Expertise in automatic speech recognition (ASR) and text-to-speech (TTS).
• Experience with voice AI toolkits like Whisper and Hugging Face Transformers.

Responsibilities

• Design APIs and inference services for voice interactions.
• Lead model optimization for latency and inference cost.
• Collaborate with teams to prototype and productionize voice AI ideas.

Skills

Machine Learning

Voice AI

Speech Processing

Conversational AI

Python

Java/Kotlin

SQL

Education

Bachelor’s or Master’s degree in Computer Science, AI, Machine Learning

Tools

PyTorch

TensorFlow

AWS

Job description

Toast is driven by building the restaurant platform that helps restaurants adapt, take control, and get back to what they do best: building the businesses they love.

Now, more than ever, the Toast team is committed to our customers. We’re taking steps to help restaurants navigate these unprecedented times with technology, resources, and community. Our focus is on building the restaurant platform that helps restaurants adapt, take control, and get back to what they do best: building the businesses they love. And because our technology is purpose-built for restaurants, by restaurant people, restaurants can trust that we’ll deliver on their needs for today while investing in experiences that will power their restaurant of the future.

Bready* to make a change?

Toast is looking for a Staff Machine Learning Engineer to bring Voice AI capabilities into the Toast platform. You will work with engineers, data scientists and product managers to turn Voice AI solutions into business impact across product lines, including phone ordering, Toast Local app, drive thru, kiosk and menu recommendations. We need your help to create the Voice AI capabilities and infrastructure that enables our data scientists and product engineers to build, release, and monitor models at scale.

About this roll* (Responsibilities):

• Apply Voice AI expertise to help further define and improve the capabilities of Toast’s product platform
• Design APIs and inference services to support voice interactions across Toast platforms and devices.
• Work closely with product teams to translate use cases into natural, efficient, and emotionally resonant voice interactions.
• Lead model optimization efforts for latency, memory, and inference cost — including edge and mobile deployment if applicable.
• Collaborate with data scientists and ML engineers to prototype and productionize new ideas in generative speech, multilingual processing, and agentic behavior.
• Mentor junior engineers and contribute to fostering a culture of technical excellence.

Do you have the right ingredients*? (Requirements):

• Bachelor’s or Master’s degree in Computer Science, AI, Machine Learning, or related field.
• 7+ years of ML software development experience with hands-on experience in voice AI, speech processing, or conversational AI systems.
• A proven track record of shipping Agentic Voice AI solutions in production at scale.
• Deep expertise in automatic speech recognition (ASR), text-to-speech (TTS), and speech-to-speech (S2S) model development and evaluation and voice agent systems.
• Familiarity with voice AI toolkits such as Whisper, Koruru TTS, Hugging Face Transformers, or OpenAI Realtime API.
• Extensive background in voice AI technologies is required, with demonstrated expertise in toolkits such as Whisper, ESPNet, Koruru TTS, Hugging Face Transformers, and OpenAI Realtime API.
• Strong background in machine learning and signal processing.
• Proficiency in Python, Java/Kotlin and SQL and experience with ML frameworks like PyTorch or TensorFlow.
• Experience in software engineering best practices and tools including object-oriented programming, test-driven development, CI/CD, git, shell scripting, task orchestration (Airflow)
• Experience with microservice-based architecture, preferably with AWS tooling (SageMaker, DynamoDB, Athena, etc.)
• Strong communication skills, with a track record of technical leadership and cross-functional collaboration.

Special Sauce* (Nice to Haves):

• Experience with real-time speech systems, including streaming ASR or low-latency TTS/S2S.
• Familiarity with open-source speech toolkits: Kokoro TTS, ESPnet, Fairseq, OpenAI Whisper, or equivalent.
• Experience building interactive, embodied, or voice-based agents using LLMs or hybrid architectures.
• Background in deploying models to edge/mobile environments or with hardware acceleration.

Our Spread* of Total Rewards
We strive to provide competitive compensation and benefits programs that help to attract, retain, and motivate the best and brightest people in our industry. Our total rewards package goes beyond great earnings potential and provides the means to a healthy lifestyle with the flexibility to meet Toasters’ changing needs. Learn more about our benefits athttps://careers.toasttab.com/toast-benefits.

*Bread puns encouraged but not required

The base salary range for this role is listed below. The starting salary will be determined based on skills and experience. In addition to base salary, our total rewards components include cash compensation (overtime, bonus/commissions, if eligible), benefits, and equity (if eligible).

Pay Range

$155,000—$248,000 USD

Diversity, Equity, and Inclusion is Baked into our Recipe for Success

At Toast, our employees are our secret ingredient—when they thrive, we thrive.The restaurant industry is one of the most diverse, and we embrace that diversity with authenticity, inclusivity, respect, and humility. By embedding these principles into our culture and design, we create equitable opportunities for all and raise the bar in delivering exceptional experiences.

We Thrive Together

We embrace a hybrid work model that fosters in-person collaboration while valuing individual needs. Our goal is to build a strong culture of connection as we work together to empower the restaurant community. To learn more about how we work globally and regionally, check out: https://careers.toasttab.com/locations-toast.

Apply today!

Toast is committed to creating an accessible and inclusive hiring process. As part of this commitment, we strive to provide reasonable accommodations for persons with disabilities to enable them to access the hiring process. If you need an accommodation to access the job application or interview process, please contact [e-mail].

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For roles in the United States, It is unlawful in Massachusetts to require or administer a lie detector test as a condition of employment or continued employment. An employer who violates this law shall be subject to criminal penalties and civil liability.