Machine Learning Engineer, Fraud

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.

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.

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.

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.

About the TeamThe Applied team is dedicated to responsibly introducing OpenAI's groundbreaking technology to the global community. We have launched revolutionary products like ChatGPT, Plugins, DALL·E, and APIs for GPT-5, embeddings, and fine-tuning. Additionally, we manage extensive inference infrastructure to support our rapidly advancing initiatives.Our clients leverage our APIs to create dynamic businesses with innovative product features previously thought impossible. For instance, ChatGPT exemplifies the capabilities our technology currently offers. We prioritize the responsible use of our powerful tools, ensuring that safety remains paramount over unrestricted growth.The Fraud Engineering team operates within the Applied Engineering organization, focusing on identifying and mitigating fraudulent activities on our platform. We are seeking a software engineer with expertise in anti-fraud and abuse systems to help us design and implement next-generation solutions.About the RoleThe Scaled Abuse team safeguards OpenAI’s products and users by detecting, preventing, and addressing fraudulent and abusive activities on a large scale. We develop and maintain backend and data systems that facilitate real-time detection, investigative workflows, and enforcement, ensuring a balance between robust protection and an excellent user experience as our platform evolves.Our work lies at the convergence of engineering and abuse prevention expertise. We collaborate closely with Trust & Safety, Security, and Product teams to identify emerging attack trends, translate complex signals into actionable system behavior, and continuously enhance our defenses. We value engineers who can navigate unfamiliar codebases swiftly, develop a deep understanding of system functionality, and suggest practical improvements to enhance overall resilience.In This Role, You Will:Design and develop systems for fraud detection and remediation, balancing fraud loss, implementation costs, and customer experience.Collaborate with finance, security, product, research, and trust & safety teams to effectively combat fraudulent and abusive behaviors on our platform.Stay updated with the latest techniques and tools to remain ahead of determined adversaries.Utilize GPT-5 and future models to enhance our fraud and abuse mitigation efforts.You May Thrive in This Role If You:Possess at least 5 years of software engineering experience, particularly in backend and data systems.

At Discord, we empower over 200 million users each month to connect, communicate, and collaborate in their gaming experiences. With more than 90% of our users engaging in video games, our platform serves as a vital hub for gaming communities. Our mission is to enhance the social aspect of gaming by enabling seamless interactions among players before, during, and after gameplay.Discord is dedicated to fostering a sense of belonging for all users. Our commitment to security and privacy ensures that communications remain safe and confidential, which is essential to our continued success.We are on the lookout for a talented Senior Detection and Response Engineer to join our dynamic Detection & Response Team (DART). Our team is focused on engineering innovative detection systems, automating response processes, and developing tools to proactively combat threats rather than merely responding to them. If you are passionate about security and enjoy transforming investigative insights into robust automated solutions, we would love to hear from you!

About Extend:Extend is transforming the post-purchase landscape for retailers and their customers by delivering AI-driven solutions that boost customer satisfaction and stimulate revenue growth. Our all-inclusive platform automates customer service, streamlines returns and exchanges, manages fulfillment end-to-end, and ensures product and shipping protection, all while providing top-tier fraud detection services. By combining cutting-edge technology with outstanding customer service, Extend enables businesses to foster trust and loyalty among consumers, while cutting costs and amplifying profits.Currently, Extend collaborates with over 1,000 prominent merchant partners across various sectors such as fashion, cosmetics, furniture, jewelry, consumer electronics, auto parts, sports and fitness, and beyond. Backed by leading technology investors, our headquarters is located in the vibrant heart of San Francisco.About the Role:This is a Full-Time Evening position requiring availability Monday through Friday from 2:00 PM to 11:00 PM Pacific Time. While this is a remote role within the US, we cannot accept applications from residents of California. You do not need to reside in the Pacific Time zone to apply; however, the working hours will remain as stated (2:00 PM - 11:00 PM PT). Candidates who are not available to work Monday through Friday evenings from 2 PM - 11 PM PT need not apply.As a Fraud Operations Specialist, you will join a dynamic Fraud Operations team, engaging in regular fraud investigations to identify fraudulent activities and enhance the experience for genuine customers. Your investigations will help detect trends in fraud and abuse, uncovering new avenues to positively influence Extend’s internal processes. This role necessitates direct experience in fraud and abuse operations (preferably in an eCommerce context), a strong grasp of fraud concepts, excellent communication skills to collaborate with cross-functional stakeholders, and proficiency in spreadsheet and data processing software.What You Will Be Doing:Real-Time Claim Review: Analyze claims in real-time for potential fraud or abuse cases, utilizing your information-gathering and communication abilities to ensure adequate evidence for fraud determinations, while providing insightful feedback for Extend’s risk models.Risk Score Judgments: Assess customer behaviors to determine risk scores and contribute to the refinement of risk assessment models.

Founded in 2007, Airbnb has transformed travel by connecting hosts and guests in over 190 countries. With a community of more than 5 million hosts, we facilitate unique stays and experiences, enabling guests to immerse themselves in local cultures.Join Our Trust-Focused Community:At Airbnb, trust is our top priority, and our dedicated team works tirelessly to ensure a safe and secure platform. As part of the Trust team, you will play a crucial role in safeguarding our community from fraud and ensuring the quality of our hosts, guests, and listings. This involves combating both online threats like account compromise and offline risks such as property damage and personal safety. Your work will help us build and maintain trust within our vibrant community.Make a Significant Impact:In your role within the Trust Engineering team, you will design and implement large-scale systems aimed at detecting and mitigating fraudulent activities across our platform. Collaborating closely with product, data science, and operations teams, you will develop real-time risk detection services that adapt to evolving threats, helping to make Airbnb the safest and most trusted platform in the industry.Your Daily Responsibilities:Design and operate resilient, scalable distributed systems.Enhance platform capabilities to counteract the evolving fraud landscape, collaborating with various engineering teams.Contribute vital insights to the Trust Platform's roadmap and strategic initiatives.

Extend seeks a Fraud Operations Specialist I to join its remote US team. This position plays a key role in protecting both merchants and customers by investigating potential fraud and supporting a secure transaction environment. The work centers on analyzing data, identifying suspicious patterns, and helping refine risk management processes. What you will do Review claims in real time: Assess incoming claims for signs of fraud or abuse. Collect relevant information, communicate findings, and offer insights that help improve risk models. Make risk score judgments: Analyze customer behavior and incidents using various data sources. Begin with evaluating risk scores and progress to recommending claim approvals or denials based on your assessments. Lead fraud investigations: Conduct thorough investigations and share updates on emerging fraud and abuse trends with the team. Follow procedures: Manage each investigation from start to finish, adhere to all regulatory and departmental guidelines, base decisions on evidence, and report any discrepancies you encounter. Requirements Experience in fraud operations, preferably within eCommerce Strong communication skills Comfort with spreadsheets and data analysis tools Extend supports more than 1,000 merchant partners across industries like fashion, electronics, furniture, and more. The company combines advanced technology and attentive support to help partners manage post-purchase needs, including fraud detection. This role is fully remote within the United States.

Role Overview Pinterest is hiring a Security Software Engineer II focused on Detection and Response. This role can be based in San Francisco, CA or remote within the US. What You Will Do Develop and refine detection strategies to identify security threats across the Pinterest platform. Implement and improve response protocols to address incidents efficiently. Work closely with teams from different disciplines to spot vulnerabilities and strengthen defenses. Support efforts to reduce incident response times and protect the safety of Pinterest’s user community. Location This position is open to candidates in San Francisco, CA or remote within the United States.

About the RoleOpenAI is seeking a dynamic Engineering Manager to spearhead a team dedicated to creating innovative software systems that proactively detect and mitigate the misuse of cutting-edge AI models. In this pivotal role, you will be at the forefront of building production services, detection pipelines, and preventive mechanisms that safeguard the integrity of our frontier models while minimizing the risk of high-severity misuse.This position is primarily focused on system development; therefore, we are looking for a candidate with a robust software engineering background who is adept at constructing reliable systems capable of scaling to billions of users.Your Responsibilities:Lead a team of skilled software engineers in designing and developing detection and mitigation systems aimed at preventing frontier model misuse, particularly focusing on model intellectual property protection and distillation detection.Establish the technical roadmap and execution strategy: prioritize tasks, design solutions, implement them, iterate based on feedback, and measure impact.Develop scalable production systems: services, pipelines, tooling, instrumentation, and automation that align with the usage of frontier models.Collaborate closely with Research and Product teams to translate evolving model capabilities into actionable tests, signals, and mitigations deployable at scale.Champion strong engineering principles: architecture design, system reliability, performance monitoring, and operational excellence.Recruit and nurture an exceptional team across backend systems, data engineering, and applied machine learning domains.Anticipate potential failures at scale as agentic workflows become increasingly sophisticated.Ideal Candidate Profile:Experience in building systems within adversarial and rapidly changing environments.Comfortable navigating ambiguity and novel situations.Familiarity with security-related domains (e.g., abuse prevention, fraud detection, platform defense, authentication/identity, and managing adversarial environments).Ability to communicate effectively and build trust with senior stakeholders—demonstrating a pragmatic, collaborative approach while remaining composed under scrutiny.Proven track record of leading engineering teams and delivering production systems from inception to deployment.Strong technical acumen in system design, distributed architectures, data pipelines, and operational observability.

About GridwareGridware is an innovative technology firm based in San Francisco, committed to safeguarding and optimizing the electrical grid. We have pioneered a revolutionary grid management approach known as Active Grid Response (AGR), which emphasizes the monitoring of electrical, physical, and environmental factors that influence grid reliability and safety. Our cutting-edge AGR platform leverages high-precision sensors to identify potential issues early, facilitating proactive maintenance and fault prevention. This holistic strategy aids in enhancing safety, minimizing outages, and ensuring the grid operates with maximum efficiency. Gridware is supported by prominent climate-tech and Silicon Valley investors. For further details, please visit www.Gridware.io.Role OverviewWe are looking for a talented Staff Software Engineer to act as a pivotal technical force within our team, enhancing the overall software engineering capabilities through architectural innovation, mentorship, and fostering a culture of excellence. In this role, you will design and develop the essential software systems that drive Gridware's platform. This encompasses everything from backend services that oversee our distributed network of devices to the front-end interfaces that visualize grid health, fleet diagnostics, and real-time field events.Your responsibilities will span the entire technology stack, building and scaling systems that integrate hardware, firmware, and cloud infrastructure to enable dependable communication, fleet visibility, and expedited decision-making. This position offers significant ownership and impact, allowing you to influence how our technology supports and protects critical infrastructure at scale.

About BroccoliBroccoli is revolutionizing the $500 billion home services industry by developing an AI operating system designed to empower trades businesses such as HVAC and roofing. Our intelligent AI agents handle customer interactions, manage job bookings, and ensure every lead is effectively captured.With the backing of prominent venture capital firms and a successful $27 million Series A funding round, we are on an aggressive growth trajectory. Collaborating with top private equity-backed home service platforms, we anticipate expanding our team fivefold by 2026, presenting a unique opportunity to join us early and make a significant impact.Why Join Broccoli?As a Staff Engineer, you will be instrumental in establishing the technical backbone of Broccoli AI. Your responsibilities will include ownership of critical systems, influencing architectural decisions, and shaping our development and deployment processes on a large scale.Immediate Impact: Your contributions will directly enhance production systems, benefiting hundreds of customers.Category Creation: Play a pivotal role in defining a new category of AI-powered workforce within an expansive market.Speed & Ownership: Enjoy the advantages of a small team with rapid feedback loops and substantial decision-making authority.Founder Collaboration: Partner closely with experienced founders to drive product and technical vision.What You’ll DoDesign, develop, and scale backend systems and internal tools for our AI agent platform.Take ownership of essential APIs and integrations, including systems like ServiceTitan.Lead complex features from initial design through to production deployment.Enhance real-time voice capabilities, reliability, and intelligence of AI agents.Mentor fellow engineers and help implement best practices across the team.Balance speed and quality while scaling systems to accommodate live customer traffic.What We’re Looking For7+ years of experience in backend or full-stack engineering.Strong system design and architectural skills.Proven experience in deploying and maintaining production systems at scale.Ability to thrive in high-growth, ambiguous startup environments.A proactive approach with a strong execution mindset.

Join Carta's engineering team as a Staff Software Engineer, where you will play a crucial role in developing innovative solutions that enhance our platform. You will collaborate with cross-functional teams to design, implement, and maintain scalable systems, ensuring high performance and responsiveness to requests from the front-end.We're looking for a passionate engineer who thrives in a fast-paced environment and is excited about tackling complex challenges. If you are eager to contribute to cutting-edge technology and drive impactful projects, we want to hear from you!

Role overview The Staff Software Engineer position at Amplitude, Inc. is based in San Francisco, CA. This role centers on developing and enhancing software to broaden the platform’s features. Day-to-day work includes direct software development and frequent collaboration with colleagues from various teams. What you will do Design, build, and maintain scalable software applications that support the platform’s growth. Collaborate with product managers and designers to deliver features that address user needs. Mentor junior engineers and contribute to their technical and professional development. Review code and help improve engineering practices throughout the team. Stay current with emerging technologies and industry trends to guide technical choices.

Join Cloudflare as a Detection & Mitigation Engineer, where you will play a pivotal role in enhancing our cybersecurity measures. Your expertise will help us identify and neutralize threats before they impact our clients. In this hybrid position, you will collaborate with a talented team to develop innovative solutions that safeguard our network infrastructure.

Role overview Benchling is looking for a Detection and Response Engineer in San Francisco, CA. This role focuses on protecting company systems and applications from security threats. The engineer will use experience in incident response and threat detection to help maintain strong security and system integrity.

Join our innovative team at Crusoe as a Staff Software Engineer. In this pivotal role, you will leverage your advanced software engineering skills to design, develop, and optimize cutting-edge solutions that enhance our technology stack. Collaborate with cross-functional teams to drive projects from concept to completion, ensuring high-quality deliverables that meet user needs and business objectives.

Why Join AngelListAt AngelList, we tackle some of the most challenging issues in venture capital and private markets. Our team is driven by precision, urgency, and a vision for the future. If you're passionate about transforming the startup funding landscape, this is your opportunity.About AngelListOur mission is to fuel innovation by enhancing the success rate of startups globally. We achieve this by creating the financial infrastructure that facilitates investment in transformative companies. AngelList stands at the intersection of venture capital and the startup ecosystem, supporting over $171 billion in assets and facilitating investments in more than 13,000 startups, including over 300 unicorns. With 57% of premier U.S. VC deals involving AngelList investors, we are ambitious in our goals.If you are excited about shaping the future of private markets, we invite you to join our journey.About the Role: As a Staff Software Engineer for our Nova platform, you will be pivotal in defining and designing our development processes. You will be responsible for establishing the domain model and architectural patterns that will guide our engineering team. If you are a catalyst who can empower a team of eight to perform like a team of twenty by establishing clear patterns, embedding engineering context into our codebase, and driving vital initiatives forward, we want to hear from you.