Senior Machine Learning Engineer - Fraud Detection

About CrunchyrollFounded by fans, Crunchyroll is dedicated to delivering the art and culture of anime to a vibrant community. Connecting over 100 million anime and manga enthusiasts across 200+ countries and territories, we create experiences that resonate, whether through online streaming, theatrical releases, games, merchandise, or events. Join us in shaping the future of anime!About the RoleAs a Senior Machine Learning Engineer focusing on Fraud Detection, you will collaborate with the Director of Data Science and Machine Learning within our Center for Data and Insights. This position can be based in either the Los Angeles or San Francisco area.Your expertise will drive the design and implementation of scalable machine learning models aimed at detecting account sharing fraud. Utilizing user behavior data such as geolocation, concurrent sessions, and device profiles, you will work closely with data scientists, product analysts, and data engineers to transform research prototypes into production systems that improve detection accuracy while minimizing user disruption. Your contributions will align with industry best practices, driving subscriber growth in our VOD streaming platform.Core Areas of ResponsibilityDesign and implement machine learning algorithms, including real-time anomaly detection models to identify unauthorized account sharing.Develop comprehensive ML pipelines for data preprocessing, model training, evaluation, and deployment leveraging cloud platforms.Optimize models for performance, scalability, and efficiency to accommodate high-volume streaming data.Integrate machine learning solutions with existing systems via APIs while establishing monitoring for model drift and retraining.Collaborate on A/B testing and iterative improvements to refine algorithms in response to evolving evasion tactics.

Propel the Future of Commerce with Whatnot!Whatnot stands as the premier live shopping platform across North America and Europe, where you can buy, sell, and explore your favorite items. We are revolutionizing e-commerce by merging community, shopping, and entertainment into a unique experience tailored just for you. Our remote co-located team thrives on innovation, deeply rooted in our core values. With operational hubs in the US, UK, Germany, Ireland, and Poland, we are collaboratively crafting the future of online marketplaces.From fashion and beauty to electronics and collectibles, including trading cards, comic books, and even live plants, our live auctions offer something for everyone.As one of the fastest-growing marketplaces, we seek audacious, forward-thinking problem solvers across all functions. Stay updated on the latest from Whatnot through our news and engineering blogs, and join us in empowering individuals to transform their passions into thriving businesses while fostering community through commerce. Role OverviewArchitect, train, and deploy both traditional machine learning and LLM-powered models for detecting fraudulent activities across user interactions, payment processes, and marketplace transactions.Oversee the complete architecture of fraud detection, prevention, and intervention systems—striking a balance between robust platform security and an intuitive user experience.Develop intelligent user graphs to analyze behavioral patterns, collusion networks, and account interconnections.Construct scalable data pipelines and real-time inference systems designed for high-volume, low-latency machine learning workloads.Perform in-depth behavioral and adversarial data analysis to identify emerging fraud patterns and enhance detection precision.Collaborate cross-functionally with Trust & Safety, Payments, and Infrastructure teams to create feature sets, labeling systems, and model evaluation processes.Establish model monitoring and drift detection frameworks to maintain system reliability and adaptability.Engage in fraud risk orchestration, integrating rules, models, and heuristics for automated decision-making.Define and monitor key performance metrics and dashboards for effective fraud detection and management.

Mercor is looking for a Software Engineer specializing in fraud detection. This full-time position is based in either San Francisco or New York City. The focus is on building and refining systems that protect both the company and its clients from fraudulent activity. Key responsibilities Design and develop tools to identify and reduce fraud across mercor’s platforms. Implement solutions that detect suspicious patterns and prevent threats before they escalate. Collaborate with colleagues from various disciplines to strengthen fraud detection strategies. Collaboration and technology This role requires regular interaction with engineering, product, and other internal teams. The work involves using modern technology to keep mercor’s systems secure and resilient.

Join our dynamic team at Mercury as a Staff Software Engineer specializing in Fraud Detection. In this role, you will leverage your engineering expertise to develop innovative solutions that enhance our fraud prevention strategies. Collaborate with cross-functional teams to design and implement scalable systems that protect our users and ensure the integrity of our platform.We are looking for a passionate engineer who thrives in a fast-paced environment and is eager to take on challenges that impact our customers' experience. Your contributions will play a crucial role in shaping the future of financial security.

Embrace the Future of Commerce with Whatnot!Whatnot is revolutionizing live shopping across North America and Europe, offering a vibrant platform to buy, sell, and explore your favorite items. We are redefining e-commerce by seamlessly blending community, shopping, and entertainment into a unique marketplace tailored for you. As a part of a remote co-located team, our innovation-driven culture is firmly rooted in our core values. With operational hubs in the US, UK, Germany, Ireland, and Poland, we are collectively shaping the future of online marketplaces.From fashion and beauty to electronics and collectibles like trading cards, comic books, and live plants, our live auctions cater to diverse interests.And this is just the beginning! As one of the fastest-growing marketplaces, we seek innovative, forward-thinking problem solvers across all areas. Follow our latest updates on our news and engineering blogs and be part of our mission to empower individuals to turn their passions into thriving businesses, while fostering connections through commerce. Role OverviewThe Fraud Experience team is dedicated to building intelligent, real-time systems that protect Whatnot’s marketplace from fraudulent activities. We focus on designing, developing, and deploying end-to-end, machine-learning driven systems that proactively identify and combat fraud, ensuring a transparent, user-centered enforcement approach.Your ResponsibilitiesArchitect and lead the development of comprehensive fraud detection, prevention, and intervention systems, integrating machine learning, backend, and client-side components.Construct intelligent user graphs to analyze behavioral patterns, identify collusion networks, and reveal account connectivity at scale.Design, train, and implement both traditional ML and LLM-powered models to detect fraudulent behavior across user interactions, payments, and marketplace activities.Create scalable data pipelines and real-time inference systems able to handle high-volume, low-latency machine learning tasks.Develop human-in-the-loop systems that continually enhance detection accuracy and adapt to evolving adversarial strategies.Conduct in-depth behavioral and adversarial data analysis to identify emerging fraud trends and drive continuous improvement.

Join our innovative Match Team as a Senior Machine Learning Engineer at Enigmaio, where you will play a pivotal role in developing advanced algorithms and models that enhance our matching capabilities. You will collaborate with cross-functional teams to design, implement, and optimize machine learning solutions that drive business outcomes.

About Taskrabbit:Taskrabbit is an innovative marketplace platform that seamlessly connects individuals with Taskers to manage everyday home tasks, including furniture assembly, handyman services, moving assistance, and much more.At Taskrabbit, we aim to transform lives one task at a time. We celebrate innovation, inclusion, and hard work, fostering a collaborative, pragmatic, and fast-paced culture. We seek talented, entrepreneurially minded, data-driven individuals who possess a passion for empowering others to pursue their passions. In partnership with IKEA, we are creating more opportunities for individuals to earn a consistent, meaningful income on their terms by establishing enduring relationships with clients in communities globally.Taskrabbit operates as a hybrid company, with team members located across the US and EU, and has been recognized as a Built In — Best Places to Work for 2022, 2023, and 2024, receiving accolades across various national and regional categories. Join us at Taskrabbit, where your contributions will be significant, your ideas appreciated, and your potential maximized!This position operates on a hybrid schedule, requiring two days of in-office collaboration per week. It can be based in our San Francisco office or our new New York City office (opening March 2026).About the RoleMachine Learning is a foundational element at Taskrabbit, and we are in search of an experienced Senior Machine Learning Engineer to join our team and help mold the future of ML/AI at Taskrabbit. This distinct, full-stack role is designed for someone who is enthusiastic about the entire machine learning lifecycle—from initial research and model development to constructing the robust infrastructure necessary for deploying and scaling your innovations.As a Senior Machine Learning Engineer, you will engage with exciting challenges that directly influence how users discover and interact with home services on the Taskrabbit platform. You will play a vital role in enhancing our capabilities in areas such as search ranking, content discovery, and recommendation systems. Collaborating closely with data scientists and fellow engineers, you will design and implement cutting-edge algorithms, ensuring the scalability, reliability, and optimization of our models in production alongside software engineers.

About VSCO At VSCO, we empower photographers with an innovative platform that provides essential tools, a vibrant community, and the visibility needed for creative and professional growth. We cultivate an authentic creative environment that welcomes photographers of all skill levels, offering a space that inspires opportunity, collaboration, and connection. Our mission is to support photographers in their journeys, enabling them to thrive and connect with fellow creatives and businesses through our comprehensive suite of tools, available on both mobile and desktop. We seek individuals who are passionate and proactive in advancing our mission. Our team members have the opportunity to make a significant impact, and we believe that collaborative efforts yield stronger results. Our core values are essential to our team culture and guide our hiring process. Learn more about what you can expect when joining VSCO on our Careers Page. About The Role As a Senior Machine Learning Engineer, you will harness the power of AI and machine learning to create innovative, reliable user-facing product features. You will leverage your extensive technical background and hands-on experience in deploying machine learning models to deliver impactful solutions based on real-world feedback. Your focus on measurable outcomes and customer satisfaction drives your work, blending innovation with practical implementation. You will be highly skilled in Python and adept across the data and machine learning stack, enabling you to develop and launch models efficiently while ensuring scalability and maintainability. Whether working with traditional algorithms or cutting-edge deep learning and generative AI, you will expertly navigate the complexity of each problem, managing every phase from defining the challenge to deployment and iterative improvement. Your dedication to software engineering excellence will inform your thoughtful approach to system design for machine learning, encompassing data quality, pipeline design, feature workflows, model serving, and ongoing monitoring and enhancement. By integrating machine learning deeply within our cohesive product experiences, you will collaborate effectively with cross-functional teams, aligning on objectives, defining success metrics, and driving meaningful outcomes. You will stay informed about the rapidly evolving AI landscape, maintaining a discerning perspective that allows your team to focus on significant advancements while avoiding distractions. The Day to Day Design and implement ML-powered features for search, discovery, personalization, and more.

Join Orchard as a Machine Learning Engineer and play a pivotal role in transforming data into actionable insights. In this dynamic position, you will leverage your expertise in machine learning algorithms and data analysis to develop innovative solutions that enhance our products and services.We are looking for a proactive team player who thrives in a fast-paced environment and possesses strong problem-solving skills. You will collaborate with cross-functional teams, engage with large datasets, and contribute to the design and implementation of machine learning models.

Are you ready to push the boundaries of what you believe you're capable of? At Coinbase, our vision is to enhance economic freedom globally. This is a grand, ambitious endeavor that challenges us to deliver our best every day as we construct the foundational onchain platform and shape the future of the global financial system.To drive our mission forward, we are in search of a unique candidate. We seek an individual who is not only passionate about our objective but also believes in the transformative power of cryptocurrency and blockchain technology to revolutionize the financial landscape. We are looking for someone eager to make a significant impact, who thrives under pressure while collaborating with a team of highly skilled professionals, and who actively seeks constructive feedback for continuous improvement. We want a problem-solver who embraces challenges head-on.Our work culture is intense and not suited for everyone. However, if you aspire to build the future alongside exceptional individuals and are ready to meet high expectations, this is the place for you.While many positions at Coinbase are remote-first, we are not solely remote. In-person engagements are expected throughout the year. We conduct team and company-wide offsites several times a year to promote collaboration, connection, and alignment. Your attendance is both expected and fully supported.We are looking for a Senior Machine Learning Platform Engineer to join our Machine Learning Platform team. This team is responsible for developing the core components for feature engineering, as well as training and serving ML models at Coinbase. Our platform plays a crucial role in combating fraud, personalizing user experiences, and analyzing blockchains. You will have the opportunity to leverage your engineering expertise across various aspects of large-scale ML development, including stream processing, distributed training, and highly available online services.

Join Arcade as a Senior Machine Learning Engineer, where you'll be at the forefront of AI innovation. In this pivotal role, you will leverage advanced machine learning algorithms to create and enhance cutting-edge solutions. Collaborate closely with cross-functional teams to drive impactful projects from ideation to deployment.

Saris AI develops applied AI solutions for the banking sector, with teams in San Francisco, Montreal, and Toronto. The company builds automation tools that handle complex, long-context reasoning and agent-driven decision-making. Reliability and compliance shape every product, and Saris AI's agents already manage real customer workflows in production. As revenue grows, the engineering team is expanding to enhance current offerings and explore new directions. The Senior Machine Learning Engineer role is based in San Francisco and sits within the core engineering group. The team works in a collaborative, early-stage setting, balancing infrastructure needs with the delivery of features that serve customers directly. What you will do Build and maintain machine learning infrastructure, such as evaluation frameworks, prompt management systems, and tools for model observability. Develop new AI features for customers while supporting and improving the underlying infrastructure. Shape strategies for evaluation, LLM routing, prompt engineering, and model selection. Set practical standards to boost quality without slowing down development. Guide technical direction by clarifying trade-offs and architectural choices. Requirements Minimum 4 years of experience in machine learning or AI engineering, including production deployment of ML systems. Direct experience with large language models, prompt engineering, evaluation techniques, and model routing. Background in building tools and systems that deliver value to users. Comfort making pragmatic trade-offs and recognizing when a solution is sufficient. Ability to navigate ambiguity, define problems, and deliver results independently. Strong focus on end users and understanding the impact of ML decisions on customer experience. Supports team growth through code reviews, collaboration, and clear technical communication. Bonus Experience in regulated industries, especially banking.

Highlight is pioneering a shared intelligence framework for the contemporary workforce. Our solution integrates context across every member and tool in your team, effectively eliminating information silos. As your organization evolves, Highlight adapts by intelligently routing knowledge and reliably automating workflows.The RoleWe are seeking a Senior Machine Learning Engineer to contribute to the development of the AI systems that drive Highlight's operations. This position involves working across the entire ML stack, including data pipelines, model training, retrieval, ranking, evaluations, and deployment. You will deliver features that create a seamless experience for our users. This is a hands-on individual contributor role where you will manage critical systems from inception to deployment, collaborating closely with our Head of AI Engineering to enhance our ML capabilities.You will excel in this role if you are passionate about delivering production-ready ML systems, maintaining high standards of output quality, and tackling complex problems that have a tangible impact on users. We prioritize speed, uphold rigorous standards, and believe in the merit of ideas, regardless of hierarchy.Note: This is an on-site position, requiring five days a week at our San Francisco or New York City offices.ResponsibilitiesDesign, develop, and refine ML pipelines for context retrieval, action detection, and output generation.Implement and iterate on Retrieval-Augmented Generation (RAG) systems, ranking models, and prompt engineering to enhance quality.Establish comprehensive evaluations and monitoring frameworks to assess and enhance ML system performance.Explore alternative models and fine-tuning strategies for our substantial background processing workloads, creating improved systems that enhance quality while optimizing cost efficiency.Work in collaboration with Backend and Product Engineering teams to deliver AI-powered features.Influence ML infrastructure decisions and establish best practices across the engineering organization.Stay updated on advancements in LLMs, retrieval techniques, and ML tools; share insights with the team.Candidate ProfileWe are looking for an individual who is excited about crafting the AI user experience for the future. We value extreme ownership, accountability, and proactivity as we strive to exceed expectations. The ideal candidate is a skilled craftsman who enjoys developing exceptional products utilizing LLMs at scale.You are a suitable candidate if you possess:4+ years of experience in ML/AI engineering, with substantial involvement in deploying production systems.

Join Our Team at MacroscopeAt Macroscope, we are dedicated to being the definitive source of truth for any software development company. Our mission is to empower leaders with clarity and provide engineers with the time they need to innovate.We enable leaders to gain insights into the evolution of their products and codebases—tracking changes, understanding team contributions, and identifying progress—all grounded in the ultimate source of truth: the code itself.Founded by experienced entrepreneurs who have successfully built and sold multiple companies, and held executive positions in public tech firms, we are backed by top-tier venture capital firms such as Lightspeed Venture Partners, Thrive Capital, Google Ventures, and Adverb.The RoleWe are seeking a Senior Applied Machine Learning Engineer who will be responsible for designing, developing, and optimizing the ML and AI systems that drive our core offerings. You will have full ownership of the systems, overseeing everything from data collection and evaluation to model experimentation and large-scale production deployment.This cross-functional position entails leading the ML/AI lifecycle for one of our most vital features: AI Code Review. Collaborating closely with our co-founders, you will make pivotal decisions that shape our product's development—ranging from building high-quality datasets to interpreting experimental results and enhancing model performance architecture. Additionally, you will play a significant role in crafting and implementing software that seamlessly integrates our models with our backend applications and user experience, offering a unique opportunity to influence our product's evolution significantly.Technology Stack: Typescript/React (frontend), Golang (backend), Temporal, Google Cloud (GCP), Postgres, Terraform, and custom-built AST "code walkers" in several programming languages including Golang, Typescript, Swift, Python, and Rust.

The Senior Machine Learning Engineer at Scale AI is tasked with harnessing advanced methodologies in generative AI, computer vision, reinforcement learning, and agentic AI to enhance our product offerings and streamline the customer experience in live environments. Our machine learning engineers utilize a robust internal infrastructure and unparalleled access to extensive datasets to drive significant improvements for our clients. As part of the Public Sector Machine Learning team, you will be at the forefront of deploying innovative models to critical government systems through groundbreaking products such as Donovan and Thunderforge. Our work encompasses various modalities, with a strong emphasis on large language models and computer vision. On the LLM front, we are developing sophisticated agentic systems designed to address intricate operational and planning challenges for government entities. This involves creating agent frameworks that interface with custom retrieval systems and production APIs, alongside evaluation tools for assessing and refining agent performance. Additionally, we are pioneering research in reinforcement learning for agentic LLMs, successfully deploying these innovations in real-world operational contexts. In the realm of computer vision, we are focused on training advanced models to boost labeling throughput and automate perception tasks. Our initiatives include developing large-scale fine-tuning pipelines, training models across diverse modalities, and creating adaptable vision foundation models to support a variety of defense applications.

Join Handshake as a Machine Learning Engineer I, where you will have the opportunity to work on cutting-edge machine learning projects that drive our innovative solutions. Collaborate with a talented team to develop algorithms and models that enhance our product offerings and improve user experiences.

Join Our Innovative Team at HiveHive is at the forefront of cloud-based AI solutions, revolutionizing how organizations understand, search for, and generate content. Trusted by many of the world's largest and most groundbreaking companies, we empower developers with premier pre-trained AI models that handle billions of API requests monthly. Our turnkey software applications leverage proprietary AI models and datasets, driving transformative advancements in content moderation, brand protection, sponsorship measurement, and context-based ad targeting.With over $120M in funding from prominent investors like General Catalyst, 8VC, Glynn Capital, Bain & Company, and Visa Ventures, Hive is rapidly expanding. Our dynamic team of over 250 employees operates from our San Francisco, Seattle, and Delhi offices. If you are passionate about shaping the future of AI, we invite you to explore opportunities with us!About the Machine Learning Engineer RoleAs we strive to achieve our ambitious vision, we seek exceptional machine learning engineers to join our team. We are looking for enthusiastic developers who are eager to remain at the cutting edge of deep learning technology, designing and deploying state-of-the-art neural network models into production. Our ideal candidates thrive in working with large-scale datasets and demonstrate a keen interest in mastering new technologies across the machine learning spectrum. We value individuals who are proactive and take ownership of their projects, contributing innovative ideas and practical implementations. Experience in building machine learning applications from the ground up and designing scalable, maintainable data pipelines is essential.

Join our dynamic Personalization team at Boomtrain as a Machine Learning Engineer. We are in search of a skilled engineer who will play a pivotal role in developing and enhancing our recommendation systems that cater to a variety of customers.In this role, you will collaborate with a talented team dedicated to designing and implementing innovative models and systems that deliver personalized recommendations. You will have the opportunity to work on complex engineering challenges and contribute to generating hundreds of millions of recommendations daily.This position offers a unique chance to engage in end-to-end project work and make a significant impact on our personalization initiatives.Key Responsibilities:Research and propose advanced recommendation and optimization models to enhance our personalization systems.Develop and maintain offline model generation pipelines.Design and maintain online recommendation serving systems.

About FaireFaire is a transformative online wholesale marketplace, driven by the conviction that local businesses are the future. Independent retailers around the globe generate more revenue than massive corporations like Walmart and Amazon combined, yet individually, they remain small. At Faire, we harness technology, data, and machine learning to connect this vibrant community of entrepreneurs. Think of your favorite local boutique — we empower them to discover and sell the best products from around the world. With our innovative tools and insights, we aim to level the playing field, enabling small businesses to thrive against larger competitors.By championing the growth of independent businesses, Faire positively impacts local economies on a global scale. We’re in search of intelligent, resourceful, and passionate individuals to join us in fueling the shop local movement. If you value community, we invite you to be part of ours.About this RoleAs the Senior Staff Machine Learning Platform Engineer, you will spearhead the technical vision and evolution of Faire's ML platform. You will establish standards, influence organization-wide architecture, and lead intricate, cross-functional initiatives that enhance data science velocity at scale. This position is crucial for adapting ML workflows to leverage modern AI productivity tools. You will not only develop models but also design the systems that enable those models to empower tens of thousands of small retailers in competing and growing their local businesses.

Discord is a vibrant platform utilized by over 200 million individuals each month for various activities, with one common passion uniting them: gaming. An astounding 90% of our users engage in gaming, collectively dedicating 1.5 billion hours to a diverse array of titles on Discord every month. We envision Discord as a pivotal player in the future of gaming, dedicated to enhancing communication and camaraderie among players before, during, and after their gaming sessions.We are in search of a Senior Machine Learning Engineer to become a key member of our Revenue ML team at Discord. This role is strategically positioned at the crossroads of our two primary revenue initiatives — our expanding first-party Shop and our newly introduced Game Commerce platform, which connects players to in-game items from renowned publishers such as Marvel Rivals, Fortnite, Valorant, and many others. You will be the pioneering ML expert for commerce discovery and personalization, constructing systems from scratch that will drive recommendations, social commerce features, and targeted marketing across both our first-party and third-party storefronts.This position is high-impact and offers significant leverage. Discord’s social ecosystem provides us with a distinct commercial advantage — robust social graphs, enthusiastic fan communities, and an inherent gaming context — and you will be the visionary who transforms this into ML-driven products that generate substantial GMV growth.Key Responsibilities:Develop and oversee the ML infrastructure for commerce discovery, including user, item, and interaction embeddings that facilitate personalized recommendations across various shop interfaces (homepage, cart, post-purchase, wishlist, etc.).Create and implement scalable real-time recommendation and ranking systems that efficiently manage a growing catalog of first-party and third-party items from diverse game publishers.Build ML-enhanced marketing targeting systems that accurately identify the ideal users for tailored campaigns — such as new buyer discounts, drop campaigns, weekly deals, and seasonal promotions — driving conversion rates without conditioning users to expect discounts.Utilize Discord's unique social graph to innovate social commerce ML applications: predicting gifting recipients, modeling group buying conversions, and generating friend-group recommendations that set Discord apart from traditional game storefronts.Lead the development of deep learning A/B testing infrastructure and model monitoring to convert experimentation insights into actionable product strategies.Collaborate closely with Shop, Game Commerce, Revenue Infra, ML Infra, and Data Engineering teams to outline ML requirements, identify integration points, and influence the commerce roadmap.