Custom policy checks help democratize automated reasoning

New IAM Access Analyzer feature uses automated reasoning to ensure that access policies written in the IAM policy language don’t grant unintended access.

To control access to resources in the Amazon Web Services (AWS) Cloud, customers can author AWS Identity and Access Management (IAM) policies. The IAM policy language is expressive, allowing you to create fine-grained policies that control who can perform what actions on which resources. This control can be used to enforce the principle of least privilege, granting only the permissions required to perform a task.

But how can you verify that your IAM policies meet your security requirements? At AWS’s 2023 re:Invent conference, we announced the launch of IAM Access Analyzer custom policy checks, which help you benchmark policies against your security standards. Custom policy checks abstract away the task of converting policy statements into mathematical formulas, so customers can enjoy the benefits of automated reasoning without expertise in formal logic.

Policy checks in context.png
The role of IAM Access Analyzer custom policy checks in the development pipeline.

The IAM Access Analyzer API CheckNoNewAccess ensures that you do not inadvertently add permissions to a policy when you update it. With the CheckAccessNotGranted API, you can specify critical permissions that developers should not grant in their IAM policies.

We built custom policy checks on an internal AWS service called Zelkova, which uses automated reasoning to analyze IAM policies. Previously, we used Zelkova to build preventative and detective managed controls, such as Amazon S3 Block Public Access and IAM Access Analyzer public and cross-account findings. Now, with the release of custom policy checks, you can set a security standard and prevent policies that do not meet this standard from being deployed.

How does Zelkova work?

Zelkova models the semantics of the IAM policy language by translating policies into precise mathematical expressions. It then uses automated engines called satisfiability modulo theories (SMT) solvers to check properties of the policies. Satisfiability (SAT) solvers check if it is possible to assign true or false values to Boolean variables to satisfy a set of constraints; SMT is a generalization of SAT to include strings, integers, real numbers, or functions. The benefit of using SMT to analyze policies is that it is comprehensive. Unlike tools that simulate or evaluate a policy for a given request or a small set of requests, Zelkova can check properties of a policy for all possible requests.

Consider the following Amazon S3 bucket policy:

{
   "Version": "2012-10-17",
   "Statement": [
      {
         "Effect": "Allow",
         "Principal": "*",
         "Action": ["s3:PutObject"],
         "Resource": "arn:aws:s3:::DOC-EXAMPLE-BUCKET"
      }
   ]
}

Zelkova translates this policy into the following formula:

(Action = “s3:PutObject”) 
∧ (Resource = “arn:aws:s3:::DOC-EXAMPLE-BUCKET”)

In this formula, "∧" is the mathematical symbol for “and”. Action and Resource are variables that represent values from any possible request. The formula is true only when a request is allowed by the policy. This precise mathematical representation of a policy is useful because it allows us to answer questions about the policy exhaustively. For example, we can ask if the policy allows public access, and we receive the answer that it does.

For simple policies such as the preceding policy, we could perform manual reviews to determine whether they allow public access: the "Principal": "*" in the policy’s statement means that anyone (the public) is allowed access. But manual review can be error prone and is not scalable.

Alternatively, we could write simple syntactic checks for patterns such as "Principal": "*". However, these syntactic checks can miss the subtleties of policies and the interactions between different parts of a policy. Consider the following modification of the preceding policy, which adds a Deny statement with "NotPrincipal": "123456789012"; the policy still has the pattern "Principal": "*", but it no longer allows public access:

{
   "Version": "2012-10-17",
   "Statement": [
      {
         "Effect": "Allow",
         "Principal": "*",
         "Action": ["s3:PutObject"],
         "Resource": "arn:aws:s3:::DOC-EXAMPLE-BUCKET"
      },
      {
         "Effect": "Deny",
         "NotPrincipal": "123456789012",
         "Action": "*",
         "Resource": "*"
      }
   ]
}

With the mathematical representation of policy semantics in Zelkova, we can answer questions about access privileges precisely.

Answering questions with Zelkova

As an example, let’s consider a relatively simple question. With IAM policies, you can grant cross-account access to resources you want to share. For sensitive resources, you’d like to check that cross-account access is not possible.

Suppose we wanted to check whether the preceding policies allow anyone outside my account, 123456789012, to access my S3 bucket. Just as we translated the policy into a mathematical formula, we can translate the question we want to ask (or property we want to check) into a mathematical formula. To check whether all allowed accesses are from my account, we can translate the property to the following formula:

(Principal = 123456789012)

To show that the property holds true for the policy, we can now try to prove that only requests with (Principal = 123456789012) are allowed by the policy. A common trick used in mathematics is to flip the question around. Instead of trying to prove that the property holds, we can prove that it does not hold by finding requests that do not satisfy it — in other words, requests that satisfy (Principal 123456789012). To find such a counterexample, we look for assignments to the variables Principal, Action, and Resource such that the following is true:

(Action = “s3:PutObject”)
∧ (Resource = “arn:aws:s3:::DOC-EXAMPLE-BUCKET”)
∧ (Principal ≠ 123456789012)

Zelkova translates the policy and property into the preceding mathematical formula, and it efficiently searches for counterexamples using SMT solvers. For the preceding formula, the SMT solver can produce a counterexample showing that such access is indeed allowed by the policy (for example, with Principal = 111122223333).

For the previously modified policy with the Deny statement, the SMT solver can also prove that no solution is possible for the resulting formula and that no access is allowed for the policy from outside my account, 123456789012:

(Action = “s3:PutObject”) 
∧ (Resource = “arn:aws:s3:::DOC-EXAMPLE-BUCKET”) 
∧ (Principal = 123456789012) ∧ (Principal ≠ 123456789012)

The Deny statement in the policy with "NotPrincipal": "123456789012" is translated to the constraint (Principal = 123456789012). By inspecting the preceding formula, we can see that it can’t be satisfied: the constraints on Principal from the policy and from the property are contradictory. An SMT solver can prove this and more complicated formulas by exhaustively ruling out solutions.

Custom policy checks

To democratize access to Zelkova, we needed to abstract the construction of mathematical formulas behind a more accessible interface. To that end, we launched IAM Access Analyzer custom policy checks with two predefined checks: CheckNoNewAccess and CheckAccessNotGranted.

With CheckNoNewAccess, you can confirm that you do not accidentally add permissions to a policy when updating it. Developers often start with more-permissive policies and refine them over time toward least privilege. With CheckNoNewAccess, you can now compare two versions of a policy to confirm that the new version is not more permissive than the old version.

Suppose a developer updates the first example policy in this post to disallow cross-account access but at the same time also adds a new action:

{
   "Version": "2012-10-17",
   "Statement": [
      {
         "Effect": "Allow",
         "Principal": "123456789012",
         "Action": [ 
            "s3:PutObject",
            "s3:DeleteBucket" 
         ],
         "Resource": "arn:aws:s3:::DOC-EXAMPLE-BUCKET"
      }
   ]
}

CheckNoNewAccess translates the two versions of the policy into formulas Pold and Pnew, respectively. It then searches for solutions to the formula (Pnew ¬Pold) that represent requests that are allowed by the new policy but not allowed by the old policy (“¬” is the mathematical symbol for “not”). Because the new policy allows principals in 123456789012 to perform an action that the old policy did not, the check fails, and a security engineer can review whether this policy change is acceptable.

With CheckAccessNotGranted, security engineers can be more prescriptive by specifying critical permissions to be checked against policy updates. Let’s say we want to ensure that developers are not granting permissions to delete an important bucket. In our previous example, CheckNoNewAccess detected this only because the permission was added with an update. With CheckAccessNotGranted, the security engineer can specify s3:DeleteBucket as a critical permission. We then translate the critical permissions into a formula such as (Action = “s3:DeleteBucket”) and search for requests with that action that are allowed by the policy. Because the preceding policy allows this action, the check fails and that prevents the permission from being deployed.

With the ability to specify critical permissions as parameters to the CheckAccessNotGranted API, you can now check policies against your standards — and not just for canned, broadly applicable checks.

Debugging failures

By democratizing policy checks, without the need for costly and time-consuming manual reviews, custom policy checks help developers move faster. When policies pass the checks, developers can make updates with confidence. If policies fail the checks, IAM Access Analyzer provides additional information so that developers can debug and fix them.

Suppose a developer writes the following identity-based policy:

{
   "Version": "2012-10-17",
   "Statement": [
      {
         "Effect": "Allow",
         "Action": [
            "ec2:DescribeInstance*",
            "ec2:StartInstances", 
            "ec2:StopInstances" 
         ],
         "Resource": "arn:aws:ec2:*:*:instance/*"
      },
      {
         "Effect": "Allow",
         "Action": [ 
            "s3:GetObject*", 
            "s3:PutObject",
            "s3:DeleteBucket" 
         ],
         "Resource": "arn:aws:s3:::DOC-EXAMPLE-BUCKET/*"
      }
   ]
}

Let’s also suppose that a security engineer has specified critical permissions that include s3:DeleteBucket. As described above, CheckAccessNotGranted fails on this policy.

For any given policy, it can sometimes be hard to understand why a check failed. To give developers more clarity, IAM Access Analyzer uses Zelkova to solve additional problems that pinpoint the failure to a specific statement in the policy. For the preceding policy, the check failed with the description "New access in the statement with index: 1". This description indicates that the second statement contains a critical permission.

The key to democratizing automated reasoning is to make it simple to use and easy to specify properties. With additional custom checks, we will continue to enable our customers on their journey to least privilege.

Research areas

Related content

US, NY, New York
We are seeking an Applied Scientist to develop and optimize Visual Inertial Odometry (VIO) and sensor fusion systems for our intelligent robots. In this role, you will design, implement, and deploy state estimation and tracking algorithms that enable robots to understand their position and motion in real time, even in challenging and dynamic environments. You will own the full pipeline from algorithm development through embedded deployment, ensuring that perception systems run efficiently on resource-constrained robotic hardware. You will also leverage modern machine learning approaches to push the boundaries of classical perception methods, combining learned representations with geometric techniques to achieve robust, real-time performance. This is a deeply hands-on role. You will work directly with sensors, hardware, and real-world data, while prototyping, testing, and iterating in physical environments. The ideal candidate has strong foundations in VIO and sensor fusion, practical experience optimizing algorithms for embedded platforms, and familiarity with how modern deep learning is transforming perception. Key job responsibilities - Design and implement Visual Inertial Odometry algorithms for robust real-time state estimation on robotic platforms like Sprout - Develop multi-sensor fusion pipelines integrating cameras, IMUs, and other sensing modalities for accurate pose tracking - Optimize perception and tracking algorithms for deployment on embedded hardware (e.g., ARM, GPU-accelerated edge devices) under strict latency and power constraints - Apply modern ML-based perception techniques (learned features, depth estimation, neural odometry) to complement and improve classical geometric approaches - Build and maintain calibration, evaluation, and benchmarking infrastructure for perception systems - Collaborate with hardware, controls, and navigation teams to integrate perception outputs into the robot’s autonomy stack - Lead technical projects from research prototyping through production deployment
US, WA, Seattle
Innovators wanted! Are you an entrepreneur? A builder? A dreamer? This role is part of an Amazon Special Projects team that takes the company’s Think Big leadership principle to the limits. If you’re interested in innovating at scale to address big challenges in the world, this is the team for you. As an Applied Scientist on our team, you will focus on building state-of-the-art ML models for biology. Our team rewards curiosity while maintaining a laser-focus in bringing products to market. Competitive candidates are responsive, flexible, and able to succeed within an open, collaborative, entrepreneurial, startup-like environment. At the forefront of both academic and applied research in this product area, you have the opportunity to work together with a diverse and talented team of scientists, engineers, and product managers and collaborate with other teams. Key job responsibilities - Build, adapt and evaluate ML models for life sciences applications - Collaborate with a cross-functional team of ML scientists, biologists, software engineers and product managers
US, MA, Boston
MULTIPLE POSITIONS AVAILABLE Employer: AMAZON.COM SERVICES LLC Offered Position: Economist III Job Location: Boston, Massachusetts Job Number: AMZ9898444 Position Responsibilities: Mentor and guide the applied scientists and economists in our organization and hold us to a high standard of technical rigor and excellence in science. Design and lead roadmaps for complex science projects to help SP have a delightful selling experience while creating long term value for our shoppers. Work with our engineering partners and draw upon your experience to meet latency and other system constraints. Identify untapped, high-risk technical and scientific directions, and simulate new research directions that you will drive to completion and deliver. Be responsible for communicating our science innovations to the broader internal & external scientific community. Position Requirements: Ph.D. or foreign equivalent degree in Economics or a related field and two years of research or work experience in the job offered or a related occupation. Must have two years of research or work experience in the following skill(s): 1) experience in econometrics including experience with program evaluation, forecasting, time series, panel data, or high dimensional problems; 2) experience with economic theory and quantitative methods; and 3) coding in a scripting language such as R, Python, or similar. Amazon.com is an Equal Opportunity-Affirmative Action Employer – Minority / Female / Disability / Veteran / Gender Identity / Sexual Orientation. 40 hours / week, 8:00am-5:00pm, Salary Range $159,200/year to $215,300/year. Amazon is a total compensation company. Dependent on the position offered, equity, sign-on payments, and other forms of compensation may be provided as part of a total compensation package, in addition to a full range of medical, financial, and/or other benefits. For more information, visit: https://www.aboutamazon.com/workplace/employee-benefits.#0000
US, WA, Seattle
Applied Scientists in AWS Automated Reasoning are dedicated to making AWS the best computing service in the world for customers who require advanced and rigorous solutions for automated reasoning, privacy, and sovereignty. Key job responsibilities - Solve large or significantly complex problems that require deep knowledge and understanding of your domain and scientific innovation. - Own strategic problem solving, and take the lead on the design, implementation, and delivery for solutions that have a long-term quantifiable impact. - Provide cross-organizational technical influence, increasing productivity and effectiveness by sharing your deep knowledge and experience. - Develop strategic plans to identify fundamentally new solutions for business problems. - Assist in the career development of others, actively mentoring individuals and the community on advanced technical issues.
US, WA, Seattle
Amazon's Worldwide Pricing & Promotions organization is seeking a talented, hands-on Research Scientist to join the Pricing and Promotion Optimization Science (P2OS) team — the optimization "application layer" within Amazon's Pricing Sciences organization. Amazon adjusts prices on hundreds of millions of products daily across a global marketplace; P2OS is the team that makes those prices optimal. P2OS is a small, specialized unit with an outsized charter: develop and maintain the models that determine optimal prices and promotions across Amazon's catalog and merchant programs. We own the full optimization stack — from price prediction to promotion targeting to competitiveness guardrails — and we measure success in terms of accretive Gross Contribution and Customer Pricing Perception (GCCP). Our work spans Retail Core, Amazon Business, Fresh, Grocery, and international marketplaces, and we are continually investing in more extensible, generalizable science foundations to keep pace with a growing and evolving business. We are looking for an innovative, organized, and customer-focused scientist with exceptional machine learning and predictive modeling skills, causal and experimental evaluation experience, and the entrepreneurial spirit to apply state-of-the-art methods to some of the most impactful pricing problems in e-commerce. You should be comfortable with ambiguity, motivated by measurable business impact, and excited by the opportunity to work at Amazon-scale. Key job responsibilities * Innovate and build. Design, develop, and deploy machine learning models that set optimal prices and promotions across Amazon's global catalog. Own models end-to-end — from problem formulation and data analysis through offline evaluation, A/B testing, and production launch. * Build a generalizable science foundation. Develop models and evaluation frameworks designed to scale across merchant programs, product categories, and marketplaces — enabling cross-learning and reducing the time and cost of applying science to new business contexts. * Build and evolve optimization systems. Design and improve optimization systems — including reinforcement learning and multi-objective optimization approaches — that automate price and promotion decisions at scale across millions of products. * Apply generative AI and foundation models. Identify and pursue opportunities to leverage large language models, embeddings, and generative AI techniques in pricing science — from enriching product representations and extracting competitive signals from unstructured data, to building more capable and explainable pricing systems. * Experiment rigorously. Design and execute A/B tests and causal inference studies to measure the business and customer impact of pricing model changes. Translate findings into production-ready science improvements. * Stay at the frontier. Establish mechanisms to track the latest advances in reinforcement learning, causal ML, multi-objective optimization, generative AI, and demand modeling — and identify opportunities to apply them to Pricing & Promotions business problems. * See the big picture. Contribute to the long-term scientific vision for how Amazon sets competitive, perception-preserving prices — balancing profitability, customer trust, and marketplace health.
US, CA, San Francisco
Amazon is on a mission to redefine the future of automation — and we're looking for exceptional talent to help lead the way. We are building the next generation of advanced robotic systems that seamlessly blend cutting-edge AI, sophisticated control systems, and novel mechanical design to create adaptable, intelligent automation solutions capable of operating safely alongside humans in dynamic, real-world environments. At Amazon, we leverage the power of machine learning, artificial intelligence, and advanced robotics to solve some of the most complex operational challenges at a scale unlike anywhere else in the world. Our fleet of robots spans hundreds of facilities globally, working in sophisticated coordination to deliver on our promise of customer excellence — and we're just getting started. As a Sr. Scientist in Robot Navigation, you will be at the forefront of this transformation — architecting and delivering navigation systems that are intelligent, safe, and scalable. You will bring deep expertise in learning-based planning and control, a strong understanding of foundation models and their application to embodied agents, and as well as have in-depth understanding of control-theoretic approaches such as model predictive control (MPC)-based trajectory planning. You will develop navigation solutions that seamlessly blend data-driven intelligence with principled control-theoretic guarantees. Our vision is bold: to build navigation systems that allow robots to move fluidly and safely through dynamic environments — understanding context, anticipating change, and adapting in real time. You will lead research that bridges the gap between cutting-edge academic advances and production grade deployment, collaborating with world-class teams pushing the boundaries of robotic autonomy, manipulation, and human-robot interaction. Join us in building the next generation of intelligent navigation systems that will define the future of autonomous robotics at scale. Key job responsibilities - Design, develop, and deploy perception algorithms for robotics systems, including object detection, segmentation, tracking, depth estimation, and scene understanding - Lead research initiatives in computer vision, sensor fusion and 3D perception - Collaborate with cross-functional teams including robotics engineers, software engineers, and product managers to define and deliver perception capabilities - Drive end-to-end ownership of ML models — from data collection and labeling strategy to training, evaluation, and deployment - Mentor junior scientists and engineers; contribute to a culture of technical excellence - Define and track key metrics to measure perception system performance in real-world environments - Publish research findings in top-tier venues (CVPR, ICCV, ECCV, ICRA, NeurIPS, etc.) and contribute to patents A day in the life - Train ML models for deployment in simulation and real-world robots, identify and document their limitations post-deployment - Drive technical discussions within your team and with key stakeholders to develop innovative solutions to address identified limitations - Actively contribute to brainstorming sessions on adjacent topics, bringing fresh perspectives that help peers grow and succeed — and in doing so, build lasting trust across the team - Mentor team members while maintaining significant hands-on contribution to technical solutions About the team Our team is a group is a diverse group of scientists and engineers passionate about building intelligent machines. We value curiosity, rigor, and a bias for action. We believe in learning from failure and iterating quickly toward solutions that matter.
US, NY, New York
The Sponsored Products and Brands team at Amazon Ads is re-imagining the advertising landscape through generative AI technologies, revolutionizing how millions of customers discover products and engage with brands across Amazon.com and beyond. We are at the forefront of re-inventing advertising experiences, bridging human creativity with artificial intelligence to transform every aspect of the advertising lifecycle from ad creation and optimization to performance analysis and customer insights. We are a passionate group of innovators dedicated to developing responsible and intelligent AI technologies that balance the needs of advertisers, enhance the shopping experience, and strengthen the marketplace. If you're energized by solving complex challenges and pushing the boundaries of what's possible with AI, join us in shaping the future of advertising. About the team SPB Agent team's vision is to build a highly personalized and context-aware agentic advertiser guidance system that seamlessly integrates Large Language Models (LLMs) with sophisticated tooling, operating across all experiences. The SPB-Agent is the central agent that interfaces with advertisers across Ads Console, Selling Partner portals (Seller Central, KDP, Vendor Central), and internal Sales systems. We identify high-impact opportunities spanning from strategic product guidance to granular optimization and deliver them through personalized, scalable experiences grounded in state-of-the-art agent architectures, reasoning frameworks, sophisticated tool integration, and model customization approaches including fine-tuning, MCP, and preference optimization. This presents an exceptional opportunity to shape the future of e-commerce advertising through advanced AI technology at unprecedented scale, creating solutions that directly impact millions of advertisers.
US, WA, Seattle
Applied Scientists in AWS Automated Reasoning are dedicated to making AWS the best computing service in the world for customers who require advanced and rigorous solutions for automated reasoning, privacy, and sovereignty. Key job responsibilities The successful candidate will: - Solve large or significantly complex problems that require deep knowledge and understanding of your domain and scientific innovation. - Own strategic problem solving, and take the lead on the design, implementation, and delivery for solutions that have a long-term quantifiable impact. - Provide cross-organizational technical influence, increasing productivity and effectiveness by sharing your deep knowledge and experience. - Develop strategic plans to identify fundamentally new solutions for business problems. - Assist in the career development of others, actively mentoring individuals and the community on advanced technical issues. A day in the life This is a unique and rare opportunity to get in early on a fast-growing segment of AWS and help shape the technology, product and the business. You will have a chance to utilize your deep technical experience within a fast moving, start-up environment and make a large business and customer impact. About the team Diverse Experiences Amazon Automated Reasoning values diverse experiences. Even if you do not meet all of the qualifications and skills listed in the job description, we encourage candidates to apply. If your career is just starting, hasn't followed a traditional path, or includes alternative experiences, don't let it stop you from applying. Why Amazon Automated Reasoning? At Amazon, automated reasoning is central to maintaining customer trust and delivering delightful customer experiences. Our organization is responsible for creating and maintaining a high bar for automated reasoning across all of Amazon's products and services. We offer talented automated reasoning professionals the chance to accelerate their careers with opportunities to build experience in a wide variety of areas including cloud, devices, retail, entertainment, healthcare, operations, and physical stores. Inclusive Team Culture In Amazon Automated Reasoning, it's in our nature to learn and be curious. Ongoing DEI events and learning experiences inspire us to continue learning and to embrace our uniqueness. Addressing the toughest automated reasoning challenges requires that we seek out and celebrate a diversity of ideas, perspectives, and voices. Training & Career Growth We're continuously raising our performance bar as we strive to become Earth's Best Employer. That's why you'll find endless knowledge-sharing, training, and other career-advancing resources here to help you develop into a better-rounded professional. Work/Life Balance We value work-life harmony. Achieving success at work should never come at the expense of sacrifices at home, which is why flexible work hours and arrangements are part of our culture. When we feel supported in the workplace and at home, there's nothing we can't achieve.
US, WA, Seattle
Applied Scientists in AWS Automated Reasoning are dedicated to making AWS the best computing service in the world for customers who require advanced and rigorous solutions for automated reasoning, privacy, and sovereignty. Key job responsibilities The successful candidate will: - Solve large or significantly complex problems that require deep knowledge and understanding of your domain and scientific innovation. - Own strategic problem solving, and take the lead on the design, implementation, and delivery for solutions that have a long-term quantifiable impact. - Provide cross-organizational technical influence, increasing productivity and effectiveness by sharing your deep knowledge and experience. - Develop strategic plans to identify fundamentally new solutions for business problems. - Assist in the career development of others, actively mentoring individuals and the community on advanced technical issues. A day in the life This is a unique and rare opportunity to get in early on a fast-growing segment of AWS and help shape the technology, product and the business. You will have a chance to utilize your deep technical experience within a fast moving, start-up environment and make a large business and customer impact. About the team Diverse Experiences Amazon Automated Reasoning values diverse experiences. Even if you do not meet all of the qualifications and skills listed in the job description, we encourage candidates to apply. If your career is just starting, hasn't followed a traditional path, or includes alternative experiences, don't let it stop you from applying. Why Amazon Automated Reasoning? At Amazon, automated reasoning is central to maintaining customer trust and delivering delightful customer experiences. Our organization is responsible for creating and maintaining a high bar for automated reasoning across all of Amazon's products and services. We offer talented automated reasoning professionals the chance to accelerate their careers with opportunities to build experience in a wide variety of areas including cloud, devices, retail, entertainment, healthcare, operations, and physical stores. Inclusive Team Culture In Amazon Automated Reasoning, it's in our nature to learn and be curious. Ongoing DEI events and learning experiences inspire us to continue learning and to embrace our uniqueness. Addressing the toughest automated reasoning challenges requires that we seek out and celebrate a diversity of ideas, perspectives, and voices. Training & Career Growth We're continuously raising our performance bar as we strive to become Earth's Best Employer. That's why you'll find endless knowledge-sharing, training, and other career-advancing resources here to help you develop into a better-rounded professional. Work/Life Balance We value work-life harmony. Achieving success at work should never come at the expense of sacrifices at home, which is why flexible work hours and arrangements are part of our culture. When we feel supported in the workplace and at home, there's nothing we can't achieve.
GB, London
Are you excited about using econometrics, experimentation, and machine learning to impact real-world business decisions? We are looking for an Economist II to work on challenging problems at the intersection of causal inference and machine learning for Prime Video Ads. You will design experiments, build econometric and ML models, and translate findings into decisions that shape how millions of customers experience advertising on Prime Video. If you have a deeply quantitative approach to problem-solving, enjoy building and implementing models end-to-end, and want to work on problems where rigorous economics meets production-scale ML, we want to talk to you. Key job responsibilities - Design, execute, and analyze experiments to measure the impact of ad policies on customer behavior and business outcomes - Develop causal inference models (experimental and observational) to estimate short- and long-term effects of strategic initiatives - Collaborate with scientists, engineers, and product teams to deliver measurable business impact - Influence business leaders based on empirical findings