ML Engineer - Verifications

Staff Full Stack Engineer, Identity

Stripe

WHO WE ARE ABOUT STRIPE Stripe is a financial infrastructure platform for businesses. Millions of companies—from the world's largest enterprises to the most ambitious startups—use Stripe to accept payments, grow their revenue, and accelerate new business opportunities. Our mission is to increase the GDP of the internet, and we have a staggering amount of work ahead. That means you have an unprecedented opportunity to put the global economy within everyone's reach while doing the most important work of your career. ABOUT THE TEAM Before Stripe, every growing internet platform had a payments team. Today, every growing internet platform has an Identity team. Identity verification has become core economic infrastructure for online businesses — enabling them to digitally verify their users' identities for fraud prevention, regulatory compliance, and trust and safety purposes. At Stripe, we're building something more ambitious than a verification product. Our vision is to build the world's most trusted store of verified identities — a single, global, reusable, risk-scored representation of every individual who interacts with Stripe and beyond. This Identity Store becomes a platform with compounding network effects: more verifications enrich the store; a richer store produces better fraud signals; better signals mean lower friction for trusted users; lower friction drives more adoption. Our product today serves millions of verifications per month for customers like OpenAI, Shopify, and WhatNot, and powers identity verification across multiple internal Stripe products including Fraud, Link, Connect, and Crypto. The problems ahead — adversarial AI and deepfake defense, networked identity infrastructure, progressive verification platforms, and low friction KYC APIs — sit at the frontier of what's possible in identity engineering. This role is open to candidates based in our Seattle, New York, or San Francisco offices, or remote within the US. For Stripes who live within 35 miles of an office, we offer a hybrid work environment with an expectation of in-office presence 50% of your working days each month. WHAT YOU'LL DO As a Full Stack Staff Engineer on the Identity team, you will own the technical direction of one of Stripe's most strategically important product areas. This is not a role defined by task execution — it's a role defined by technical judgment, architectural influence, and the ability to turn an ambitious vision into a reliable, scalable system. RESPONSIBILITIES * Own technical strategy — Define the architecture for Identity's core systems (Identity Store, headless verification platform, fraud detection infrastructure), make build vs. buy vs. partner decisions, and surface technical risks before they become customer-facing failures * Lead 0-1 platform development — Architect net-new systems including the Identity Store, Networked Identity platform, and advanced fraud detection pipeline (behavioral biometrics, deepfake discriminators, adversarial training). Drive the evolution from a hosted-UI product to a headless-API and embedded-components platform * Drive cross-functional alignment — Be the primary technical voice in roadmap and resourcing discussions. Partner with ML, product, legal, and engineering leads across Risk, Fraud, Link, Connect, and Crypto to ensure Identity's abstractions serve the full breadth of Stripe's product surface * Raise the technical bar — Set engineering standards across ML, backend, mobile, and front-end; lead design reviews; and mentor senior engineers on the judgment needed to operate a high-stakes, externally-facing product * Operate with ownership — Be accountable for reliability, scalability, and security of the systems you design — including the observability and alerting that catch model drift and fraud pattern shifts before customers do WHO YOU ARE We're looking for someone who meets the minimum requirements to be considered for the role. If you meet these requirements, you are encouraged to apply. The preferred qualifications are a bonus, not a requirement. MINIMUM REQUIREMENTS * 10+ years of software engineering experience, including 5+ years of experience in a strategic technical leadership role * Experience leading engineering team(s) working on API design, abstractions, frameworks, or client libraries (e.g. building internal or external developer products) * Proven track record of delivering pragmatic solutions that accelerate business growth * Ability to adjust conversations from high-level discussions to detailed coding * Clear and persuasive writing and in-person communication PREFERRED QUALIFICATIONS * Experience with identity verification, fraud detection, or trust and safety systems — especially systems with adversarial inputs at scale * Familiarity with ML systems in production: model serving, training pipelines, observability, drift detection, and the feedback loops that keep models accurate under adversarial conditions * Experience building platform products with multiple consumer types — internal platform teams and external developers — where API backward compatibility and abstraction quality are first-class concerns * Prior experience with 0-1 product builds: you've started with a blank page and ended with a production system, and you have clear opinions about what makes that process go well or poorly * Experience across a range of software languages and frameworks; our stack includes primarily Ruby and TypeScript on the backend, Python for ML and data pipelines, with infrastructure spanning Kafka, Temporal, Protobuf, React, SQL (Spark and Trino dialects), Airflow, Bazel, Mongo, Splunk, and Prometheus * Experience navigating ambiguity in a fast-moving organization — you can make confident technical decisions with incomplete information and update gracefully when new constraints emerge

Applied Scientist, Pro Growth

Thumbtack

THUMBTACK HELPS MILLIONS OF PEOPLE CONFIDENTLY CARE FOR THEIR HOMES. Thumbtack is the one app you need to take care of and improve your home — from personalized guidance to AI tools and a best-in-class hiring experience. Every day in every county of the U.S., people turn to Thumbtack to complete urgent repairs, seasonal maintenance and bigger improvements. We help homeowners know which projects to do, when to do them and who to hire from our growing community of 300,000 local service businesses. If making an impact inspires you, join us. Imagine what we’ll build together. ABOUT THE APPLIED SCIENCE TEAM We’re looking for applied scientists with deep expertise in machine learning, optimization, building data products, and/or statistical models. As part of a small product team you will have full ownership over your domain, so you should be a person who dreams big, then executes well. At Thumbtack, the Applied Science team is responsible for a wide variety of problems spanning AI, machine learning, statistics, and computer science: * Improve customer and service provider matching. Matching and optimization algorithms are fundamental to Thumbtack’s product: we now service millions of matches per week. Identifying better matches between customers and service providers has an incredible impact on the experience of customers and professionals transacting on our platform. * Model complex relationships in the presence of many confounding factors. Predictive modeling problems are everywhere across our product. Our team works to scope, design and implement machine learning models to support Thumbtack’s product and marketing. * Characterize marketplace dynamics. Thumbtack’s marketplaces consist of thousands of active markets across our service categories and U.S. cities. Via exploratory data analysis and experimental design, our team works to understand trends and behaviors within these markets. * Build AI features. Use state-of-the-art approaches such as large language models (LLMs), reinforcement learning and agentic workflows to enhance customer / pro experience, increase acquisition and marketplace efficiency, and to automate and enhance internal processes. * Build a healthy marketplace. We evolve and manage the monetization mechanics of our marketplace, including defining the parameters that affect the prices we charge. THE CHALLENGE Thumbtack constantly works to balance supply and demand across thousands of local markets and hundreds of service categories. The Pro Growth pod is responsible for the science behind acquiring and activating the right pros, at the right time, in the right markets, to keep the marketplace healthy and growing. As an Applied Scientist on Pro Growth, you’ll build models and experiments that shape who joins Thumbtack, how they get activated, how we forecast supply needs by market and trade, and how we accelerate time-to-value for new pros. We leverage machine learning, causal inference, and optimization to strategically grow and shape our pro supply base. Our work directly contributes to meeting demand projections, unlocking strategic partnerships, and ultimately enhancing customer experience and platform growth by ensuring a robust and high-quality supply of pros. You’ll work shoulder-to-shoulder with engineers, product managers, and other applied scientists on a portfolio that ranges from incrementality and market forecasting to LLM-powered onboarding agents. You’ll own end-to-end: from problem framing, through experiment design, through deploying models to production, through measuring business impact. WHAT YOU’LL DO * Initiate and drive applied science projects to completion, with a focus on the business impact of those projects on pro acquisition, activation, retention, and supply health. * Develop, deploy, and optimize machine learning models for supply-side problems, including: lead scoring and pro acquisition targeting, market-level supply forecasting, pro onboarding and activation, retention and churn prediction, and agentic onboarding workflows. * Design and execute well-powered marketplace experiments to measure model and product impact on supply and business metrics. * Analyze structured and unstructured data such as marketplace interactions, pro profiles, external supply signals, to identify trends, opportunities, and risks related to supply health. * Collaborate closely with engineering, product management, business development, and marketing teams to define problems, develop end-to-end solutions, and ensure successful implementation and monitoring of ML systems in production. * Maintain the right balance between speed of execution and scientific rigor when designing solutions for a fast-paced marketplace environment. * Contribute to evolving the team’s agentic-first ways of working, including LLM-powered tooling, eval coverage, and the use of AI agents in day-to-day applied science. IN ORDER TO BE SUCCESSFUL, YOU MUST BRING * Master’s degree in a quantitative field (Computer Science, Machine Learning, Statistics, Operations Research, Economics, or related), or equivalent industry experience. * 3+ years of industry experience as an applied scientist, data scientist, or ML engineer with ownership of production ML models. * Experience in applied science within a marketplace, supply chain, or growth domain. * Solid knowledge of machine learning techniques such as classification, regression, embedding-based approaches, and causal inference. * Familiarity with modern LLMs (OpenAI, Anthropic Claude, Gemini, AWS Bedrock) and experience with agentic AI development practices and tools. * Good knowledge of probability, statistics, and econometric methods, including experimental design, causal inference, and optimization. * Experience with large-scale distributed systems (Spark, Databricks, or similar). * Ability to effectively read, write, and debug code in programming languages such as Python and SQL. * Ability to break down complex problems rigorously and understand the tradeoffs necessary to deliver impactful projects. * Ability to communicate clearly and effectively to cross-functional partners of various technical levels. * Demonstrated ability to drive seamless execution end-to-end on at least one production ML project. EXPECTED SALARY RANGES * For candidates living in Ontario and British Columbia, the expected salary range for the role is currently $161,500 - $209,000 Actual offered salaries will vary and will be based on various factors, such as calibrated job level, qualifications, skills, competencies, and proficiency for the role. Note: Thumbtack uses AI tools to support our resume screening process. However, our Recruiting team’s expertise and judgment guide hiring decisions. Actual offered salaries will vary and will be based on various factors, such as calibrated job level, qualifications, skills, competencies, and proficiency for the role. Thumbtack embraces diversity. We are proud to be an equal opportunity workplace and do not discriminate on the basis of sex, race, color, age, pregnancy, sexual orientation, gender identity or expression, religion, national origin, ancestry, citizenship, marital status, military or veteran status, genetic information, disability status, or any other characteristic protected by federal, provincial, state, or local law. We also will consider for employment qualified applicants with arrest and conviction records, consistent with applicable law. Thumbtack is committed to working with and providing reasonable accommodation to individuals with disabilities. If you would like to request a reasonable accommodation for a medical condition or disability during any part of the application process, please contact: recruitingops@thumbtack.com. For information about how Thumbtack collects, uses, and shares personal information about job applicants, please see our Job Applicant Privacy Policy. We put as much craftsmanship into candidate safety as we do into the hiring experience itself. While scammers may try to impersonate our team, we’ll never ask you for money, banking info, or SSNs during hiring. Check out our blueprint on how to spot the fakes.

Software Engineer, AI/ML Infrastructure

Thumbtack

THUMBTACK HELPS MILLIONS OF PEOPLE CONFIDENTLY CARE FOR THEIR HOMES. Thumbtack is the one app you need to take care of and improve your home — from personalized guidance to AI tools and a best-in-class hiring experience. Every day in every county of the U.S., people turn to Thumbtack to complete urgent repairs, seasonal maintenance and bigger improvements. We help homeowners know which projects to do, when to do them and who to hire from our growing community of 300,000 local service businesses. If making an impact inspires you, join us. Imagine what we’ll build together. ABOUT THE MACHINE LEARNING INFRASTRUCTURE TEAM At Thumbtack, our challenges span a wide range of areas, including search, recommendations, matchmaking, pricing, safety, content generation, fraud detection, and more. The ML Infrastructure team is responsible for centralizing, standardizing and evolving AI/ML infrastructure that enables these experiences. We empower product engineering teams by providing scalable, high-performance systems that drive AI innovation at scale. To read more about some of the engineering challenges at Thumbtack, visit our engineering blog. CHALLENGE As a Software Engineer on the ML Infrastructure team, you will work closely with product and platform engineering teams to build and evolve core AI platform capabilities. You will help design and improve systems that allow teams to develop, run, and scale GenAI-powered applications in production. Your work will directly support AI-driven experiences used by millions of customers and pros across the Thumbtack ecosystem. WHAT YOU'LL DO  * Build and evolve core AI platform capabilities that enable teams to develop, run, and scale GenAI-powered applications across Thumbtack. * Contribute to the design, development, and deployment of scalable tools and infrastructure to support the efforts of our applied scientists, including traditional ML model training and serving systems, feature and data workflows, CI/CD, orchestration, deployment, and evaluation tooling. * Work hands on across the stack, from backend services and execution infrastructure to integrations with AI models and tooling. * Partner with senior engineers to evaluate next-generation AI infrastructure frameworks and tools that help product teams harness advances in AI. * Drive projects to completion with a strong focus on business impact and measurable outcomes. * Solve complex technical problems and stay up to date with advances in this rapidly evolving space. IN ORDER TO BE SUCCESSFUL, YOU MUST BRING * 1 to 3 years of professional software engineering experience. * Strong fundamentals in data structures, algorithms, and software design. * Proficiency in at least one major programming language, and the ability to work across multiple languages. Our primary stack includes Go and Python. * Experience working with relational or NoSQL databases such as Postgres or DynamoDB. * Demonstrated ability to use AI coding tools in day-to-day workflows and validate, critique, and refine AI-generated output * Comfort operating in a fast-paced environment with a certain level of ambiguity, especially when learning and picking up new technologies when projects require it. * You operate with a bias to action, quickly learning what is needed and taking decisive steps to move work forward in ambiguous, fast-paced environments. EXPECTED SALARY RANGE * For candidates living in Ontario and British Columbia, the expected salary range for the role is currently $123,300 - $159,500.    Actual offered salaries will vary and will be based on various factors, such as calibrated job level, qualifications, skills, competencies, and proficiency for the role. Note: Thumbtack uses AI tools to support our resume screening process. However, our Recruiting team’s expertise and judgment guide hiring decisions. Actual offered salaries will vary and will be based on various factors, such as calibrated job level, qualifications, skills, competencies, and proficiency for the role. Thumbtack embraces diversity. We are proud to be an equal opportunity workplace and do not discriminate on the basis of sex, race, color, age, pregnancy, sexual orientation, gender identity or expression, religion, national origin, ancestry, citizenship, marital status, military or veteran status, genetic information, disability status, or any other characteristic protected by federal, provincial, state, or local law. We also will consider for employment qualified applicants with arrest and conviction records, consistent with applicable law. Thumbtack is committed to working with and providing reasonable accommodation to individuals with disabilities. If you would like to request a reasonable accommodation for a medical condition or disability during any part of the application process, please contact: recruitingops@thumbtack.com. For information about how Thumbtack collects, uses, and shares personal information about job applicants, please see our Job Applicant Privacy Policy. We put as much craftsmanship into candidate safety as we do into the hiring experience itself. While scammers may try to impersonate our team, we’ll never ask you for money, banking info, or SSNs during hiring. Check out our blueprint on how to spot the fakes.