Senior ML/AI Modeler, Risk Automation Machine Learning
Block, Inc. is a technology company building tools for economic empowerment, operating a portfolio of financial brands including Square, Cash App, Afterpay, TIDAL, Bitkey, and Proto. It serves sellers, consumers, artists, and bitcoin users through payments, banking, buy-now-pay-later, music streaming, and bitcoin self-custody and mining products.
Maintainer signals as of 8/23/2026
About Block, Inc.
Block, Inc. builds technology aimed at increasing access to the global economy. Its brands each unlock different aspects of the economy: Square makes commerce and financial services accessible to sellers; Cash App is an easy way to spend, send, and store money; Afterpay (Clearpay in the UK) helps customers manage spending over time; TIDAL is a music platform empowering artists as entrepreneurs; Bitkey is a self-custody bitcoin wallet; and Proto builds open, accessible bitcoin mining hardware and services. Block has been a long-time advocate for bitcoin, integrating bitcoin buying/selling and Lightning Network payments into Cash App and Square, funding open-source bitcoin infrastructure through Spiral (including the Lightning Development Kit), and engaging in bitcoin policy advocacy through groups like COPA, the Digital Energy Council, the Crypto Council for Innovation, and the Texas Blockchain Council. The company also runs a significant open source program (contributing to projects like Goose, an on-machine AI developer agent, OkHttp, Retrofit, gRPC, Envoy, and MySQL) and an AI research effort, including co-founding the Agentic AI Foundation with Anthropic and OpenAI. Block serves individual consumers, small and medium-sized businesses/merchants, artists, and developers.
Skills
Candidate Availability
Required and preferred rules are kept separate and reflect the wording in the original posting.
About the Role
Experiment with and deploy AI copilot and autopilot systems, own end-to-end ML systems, build transformer-based models using diverse risk data, and collaborate cross-functionally to deploy and monitor production systems.
Requirements
- 8+ years of machine learning modeling experience; full-stack ML experience strongly preferred.
- Master's or advanced degree in computer science, data science, operations research, applied mathematics, statistics, physics, or a related technical field.
- 3+ years of AI engineering and large language model experience; traditional NLP experience is a strong plus.
- End-to-end experience building and deploying performant ML/AI systems at scale in batch and real time.
- Experience independently owning and driving high-impact programs with cross-functional stakeholders.
- Curious, growth-oriented mindset and ability to apply first-principles thinking.
Responsibilities
- Experiment and deploy AI copilot and autopilot systems at scale.
- Own end-to-end systems including data APIs, prompt tuning, orchestration, evaluation, productionization, and monitoring.
- Build transformer-based ML models using payment transactions, connected users, asset graphs, text data, and user profiles.
- Collaborate with product, platform, engineering, and operations stakeholders to deploy and tune production systems.
- Use Python, LLMs, PyTorch, Snowflake, Airflow, data platforms, GCP, and AWS.
- Use agentic tools to accelerate research, development, DevOps, and documentation.
Benefits
- Remote work
- Medical insurance
- Flexible time off
- Retirement savings plans
- Modern family planning