Flex

Data Engineer

United States

Sponsorship not specified$160k-$220kDetected 55 days ago

PythonSQLBigQuerySnowflakeRedshiftVector DatabasesAWSGCPMachine LearningPyTorchdbtData EngineeringNLPLLMsProblem Solving

About the role

Analyze, troubleshoot, and resolve production issues rooted in data quality, model accuracy, pipeline reliability, and serving latency
Contribute to a culture of learning, problem-solving, and operational excellence
Hands-on experience deploying machine-learning models to production, owning training, inference, evaluation, and rollout, not just notebooks

Design, build, and own the data pipelines and ML services that classify product eligibility and power downstream decisions across Flex
Model the data domain (products, merchants, eligibility rules, classifications, and outcomes) in warehouses and serving systems other teams build on
Partner with backend, product, and operations stakeholders translating merchant and consumer needs into reliable data products, models, and APIs
Own and improve the architecture of the data warehouse, transformation layer, ML training and inference systems, and real-time serving paths
Collaborate on cross-functional projects connecting the full Flex experience, from consumer checkout to merchant analytics
Build and maintain evaluation harnesses, golden datasets, and observability for the models and pipelines you ship
Create and maintain documentation for data models, pipelines, and on-call runbooks
You'll partner with backend, product, and operations stakeholders to build the systems that move every eligibility decision Flex makes.

experience with a modern cloud warehouse (Snowflake, BigQuery, Redshift, or similar) and a transformation framework like dbt

Experience with serverless compute platforms for data and ML workloads (Modal, Ray, AWS Lambda, GCP Cloud Run, or similar)
Production experience with vector databases and embedding-based retrieval
Self-hosted LLM inference experience (vLLM, TGI, SGLang) and a working sense of GPU economics
Comfort reading and contributing to a Rust-based backend that consumes your APIs
Early-stage impact: your work directly shapes growth and success
Collaborative, high-trust, and transparent culture
Familiarity with at least one transformer-based ML framework (PyTorch + Hugging Face Transformers preferred) and a working sense of when classical or embedding-based models beat LLMs and when they don't

With $150 billion in annual HSA/FSA spending potential, Flex unlocks new revenue opportunities for merchants and simplifies benefit usage for consumers.

Medical, dental, and vision plans
Unlimited PTO and sick days
Paid parental leave
enabling health and wellness brands to accept HSA and FSA payments online.
The platform verifies product eligibility in real time, manages split payments, and issues Letters of Medical Necessity at checkout.
With $150 billion in annual HSA/FSA spending potential, Flex unlocks new revenue opportunities for merchants and simplifies benefit usage for consumers.
Competitive compensation and equity package
Flexible, remote-first environment

This role suits those thriving in ambiguity, taking initiative, and excited about building at an early-stage company.

Flex is an equal opportunity employer encouraging applicants from all backgrounds and life experiences.
The company celebrates diversity and does not discriminate based on race, religion, color, national origin, sexual orientation, gender identity, gender expression, age, veteran status, disability status, or any other legally protected characteristic.

This listing is sourced directly from Flex's careers page and normalized into a canonical job model.