The Senior Machine Learning Engineer will develop scalable ML systems, collaborate across teams to improve solutions, and manage critical ML infrastructure projects.
Block is one company built from many blocks, all united by the same purpose of economic empowerment. The blocks that form our foundational teams - People, Finance, Counsel, Hardware, Information Security, Platform Infrastructure Engineering, and more - provide support and guidance at the corporate level. They work across business groups and around the globe, spanning time zones and disciplines to develop inclusive People policies, forecast finances, give legal counsel, safeguard systems, nurture new initiatives, and more. Every challenge creates possibilities, and we need different perspectives to see them all. Bring yours to Block.
The Role
Block uses Machine Learning and AI across many of its products and domains. For ML practitioners Block-wide, the ML Inference & Training team provides critical infrastructure, platforms, and libraries required to develop, productionize, and observe ML models.
We are an established team of 13 engineers and 1 manager across a few countries and timezones, sitting within the ML & Data Platform organization. Our projects cover extending mature platforms (e.g online ML hosting/inference, internal python SDKs) as well as greenfield initiatives such as LLM hosting/monitoring, rearchitecting our training stack, or building out new tooling for large-scale offline evaluations.
We are looking for an enthusiastic and experienced Machine Learning Engineer to join our team and help us build out the best ML infrastructure possible. In this role, you'll work closely with applied ML teams across Block to understand their challenges - scoping and exploring opportunities to improve their ability to deliver novel ML solutions at scale.
You'll work on high-visibility, meaningful projects that can have a significant impact on Block's continued success with ML, influencing our roadmap and working across the ML Lifecycle. We welcome individuals who are passionate about building for the real world, embracing pragmatic approaches, and seeing challenges from fresh, nontraditional viewpoints.
You Will
You Have
Technologies We Use and Teach
We value general and versatile engineering skill over specific experience with our current stack, but some examples:
We're working to build a more inclusive economy where our customers have equal access to opportunity, and we strive to live by these same values in building our workplace. Block is an equal opportunity employer evaluating all employees and job applicants without regard to identity or any legally protected class. We will consider qualified applicants with arrest or conviction records for employment in accordance with state and local laws and "fair chance" ordinances. We believe in being fair, and are committed to an inclusive interview experience, including providing reasonable accommodations to disabled applicants throughout the recruitment process. We encourage applicants to share any needed accommodations with their recruiter, who will treat these requests as confidentially as possible. Want to learn more about what we're doing to build a workplace that is fair and square? Check out our I+D page .
While there is no specific deadline to apply for this role, U.S. roles are typically open for an average of 55 days before being filled by a successful candidate. Please refer to the date listed at the top of this job page for when this role was first posted.
Block takes a market-based approach to pay, and pay may vary depending on your location. U.S. locations are categorized into one of four zones based on a cost of labor index for that geographic area. The successful candidate's starting pay will be determined based on job-related skills, experience, qualifications, work location, and market conditions. These ranges may be modified in the future.
To find a location's zone designation, please refer to this resource . If a location of interest is not listed, please speak with a recruiter for additional information.
Zone A:
$228,700 - $343,100 USD
Zone B:
$217,300 - $325,900 USD
Zone C:
$205,900 - $308,900 USD
Zone D:
$194,500 - $291,700 USD
Use of AI in Our Hiring Process
We may use automated AI tools to evaluate job applications for efficiency and consistency. These tools comply with local regulations, including bias audits, and we handle all personal data in accordance with state and local privacy laws.
Contact us at [email protected] with hiring practice or data usage questions.
Every benefit we offer is designed with one goal: empowering you to do the best work of your career while building the life you want. Remote work, medical insurance, flexible time off, retirement savings plans, and modern family planning are just some of our offering. Check out our other benefits at Block.
Block, Inc. (NYSE: XYZ) builds technology to increase access to the global economy. Each of our brands unlocks different aspects of the economy for more people. Square makes commerce and financial services accessible to sellers. Cash App is the easy way to spend, send, and store money. Afterpay is transforming the way customers manage their spending over time. TIDAL is a music platform that empowers artists to thrive as entrepreneurs. Bitkey is a simple self-custody wallet built for bitcoin. Proto is a suite of bitcoin mining products and services. Together, we're helping build a financial system that is open to everyone.
The Role
Block uses Machine Learning and AI across many of its products and domains. For ML practitioners Block-wide, the ML Inference & Training team provides critical infrastructure, platforms, and libraries required to develop, productionize, and observe ML models.
We are an established team of 13 engineers and 1 manager across a few countries and timezones, sitting within the ML & Data Platform organization. Our projects cover extending mature platforms (e.g online ML hosting/inference, internal python SDKs) as well as greenfield initiatives such as LLM hosting/monitoring, rearchitecting our training stack, or building out new tooling for large-scale offline evaluations.
We are looking for an enthusiastic and experienced Machine Learning Engineer to join our team and help us build out the best ML infrastructure possible. In this role, you'll work closely with applied ML teams across Block to understand their challenges - scoping and exploring opportunities to improve their ability to deliver novel ML solutions at scale.
You'll work on high-visibility, meaningful projects that can have a significant impact on Block's continued success with ML, influencing our roadmap and working across the ML Lifecycle. We welcome individuals who are passionate about building for the real world, embracing pragmatic approaches, and seeing challenges from fresh, nontraditional viewpoints.
You Will
- Develop scalable ML/AI systems and platforms
- Be on the cutting edge of advancements in ML/AI across the industry
- Collaborate across diverse teams to deliver impactful platform solutions by understanding and generalizing the problems of cross-functional stakeholders
- Support critical ML systems used for fraud detection, language models, recommendation systems and underwriting
- Influence our roadmap and ensure we're working on the highest impact problems within the ML infrastructure domain
You Have
- 8+ years of experience in software development and/or machine learning experience with a focus on internal platforms or infrastructure
- Deep understanding of architectures for ML-backed solutions and the ML lifecycle - from data gathering, training, model evaluation, MLOps, and productionizing models (both classical ML and deep learning/LLMs)
- A desire to understand our clients' needs in order to design tools and systems that solve our customer's problems. As a platform team, our main customers are internal developers and products
- Ability to produce production-quality code and services incorporating testing, evaluation, monitoring as well as the ability to quickly adapt to a new domain, hack MVP's, and iterate to improve product
- Experience using any of the major cloud vendors for high scale production use cases
- Strong communication skills (verbal and written) with technical and non-technical stakeholders
Technologies We Use and Teach
We value general and versatile engineering skill over specific experience with our current stack, but some examples:
- Golang, Python, TypeScript, React
- gRPC, Protocol Buffers
- AWS (Sagemaker, EC2, EKS), Databricks
- NVIDIA Triton, vLLM, ONNX
We're working to build a more inclusive economy where our customers have equal access to opportunity, and we strive to live by these same values in building our workplace. Block is an equal opportunity employer evaluating all employees and job applicants without regard to identity or any legally protected class. We will consider qualified applicants with arrest or conviction records for employment in accordance with state and local laws and "fair chance" ordinances. We believe in being fair, and are committed to an inclusive interview experience, including providing reasonable accommodations to disabled applicants throughout the recruitment process. We encourage applicants to share any needed accommodations with their recruiter, who will treat these requests as confidentially as possible. Want to learn more about what we're doing to build a workplace that is fair and square? Check out our I+D page .
While there is no specific deadline to apply for this role, U.S. roles are typically open for an average of 55 days before being filled by a successful candidate. Please refer to the date listed at the top of this job page for when this role was first posted.
Block takes a market-based approach to pay, and pay may vary depending on your location. U.S. locations are categorized into one of four zones based on a cost of labor index for that geographic area. The successful candidate's starting pay will be determined based on job-related skills, experience, qualifications, work location, and market conditions. These ranges may be modified in the future.
To find a location's zone designation, please refer to this resource . If a location of interest is not listed, please speak with a recruiter for additional information.
Zone A:
$228,700 - $343,100 USD
Zone B:
$217,300 - $325,900 USD
Zone C:
$205,900 - $308,900 USD
Zone D:
$194,500 - $291,700 USD
Use of AI in Our Hiring Process
We may use automated AI tools to evaluate job applications for efficiency and consistency. These tools comply with local regulations, including bias audits, and we handle all personal data in accordance with state and local privacy laws.
Contact us at [email protected] with hiring practice or data usage questions.
Every benefit we offer is designed with one goal: empowering you to do the best work of your career while building the life you want. Remote work, medical insurance, flexible time off, retirement savings plans, and modern family planning are just some of our offering. Check out our other benefits at Block.
Block, Inc. (NYSE: XYZ) builds technology to increase access to the global economy. Each of our brands unlocks different aspects of the economy for more people. Square makes commerce and financial services accessible to sellers. Cash App is the easy way to spend, send, and store money. Afterpay is transforming the way customers manage their spending over time. TIDAL is a music platform that empowers artists to thrive as entrepreneurs. Bitkey is a simple self-custody wallet built for bitcoin. Proto is a suite of bitcoin mining products and services. Together, we're helping build a financial system that is open to everyone.
Top Skills
AWS
Databricks
Go
Grpc
Nvidia Triton
Onnx
Playwright
Protocol Buffers
Python
React
Typescript
Vllm
Block Denver, Colorado, USA Office
Denver, CO, United States
Similar Jobs at Block
Blockchain • eCommerce • Fintech • Payments • Software • Financial Services • Cryptocurrency
As Senior Lead of Complaints Management, oversee and enhance complaint resolution processes for Square and Afterpay, ensuring compliance and customer satisfaction. Lead a team to implement strategies, analyze trends, and communicate effectively with stakeholders and regulatory bodies.
Blockchain • eCommerce • Fintech • Payments • Software • Financial Services • Cryptocurrency
Lead and transform operational outsourcing strategies, manage vendor relationships, optimize costs, and implement efficiency improvements within the Risk organization.
Top Skills:
Bi ToolsData Visualization Tools
Blockchain • eCommerce • Fintech • Payments • Software • Financial Services • Cryptocurrency
Develop and deploy ML models to combat financial crimes. Collaborate with cross-functional teams, maintain documentation, and lead ML best practices.
Top Skills:
AirflowAWSBertGCPJavaKotlinLlmsNumpyPandasPrefectPythonPyTorchScikit-LearnSnowflake
What you need to know about the Colorado Tech Scene
With a business-friendly climate and research universities like CU Boulder and Colorado State, Colorado has made a name for itself as a startup ecosystem. The state boasts a skilled workforce and high quality of life thanks to its affordable housing, vibrant cultural scene and unparalleled opportunities for outdoor recreation. Colorado is also home to the National Renewable Energy Laboratory, helping cement its status as a hub for renewable energy innovation.
Key Facts About Colorado Tech
- Number of Tech Workers: 260,000; 8.5% of overall workforce (2024 CompTIA survey)
- Major Tech Employers: Lockheed Martin, Century Link, Comcast, BAE Systems, Level 3
- Key Industries: Software, artificial intelligence, aerospace, e-commerce, fintech, healthtech
- Funding Landscape: $4.9 billion in VC funding in 2024 (Pitchbook)
- Notable Investors: Access Venture Partners, Ridgeline Ventures, Techstars, Blackhorn Ventures
- Research Centers and Universities: Colorado School of Mines, University of Colorado Boulder, University of Denver, Colorado State University, Mesa Laboratory, Space Science Institute, National Center for Atmospheric Research, National Renewable Energy Laboratory, Gottlieb Institute

