Skip to yearly menu bar Skip to main content




CVPR 2024 Career Website

The CVPR 2024 conference is not accepting applications to post at this time.

Here we highlight career opportunities submitted by our Exhibitors, and other top industry, academic, and non-profit leaders. We would like to thank each of our exhibitors for supporting CVPR 2024. Opportunities can be sorted by job category, location, and filtered by any other field using the search box. For information on how to post an opportunity, please visit the help page, linked in the navigation bar above.

Search Opportunities

About the role You will join a team of 40+ Researchers and Engineers within the R&D Department working on cutting edge challenges in the Generative AI space, with a focus on creating highly realistic, emotional and life-like Synthetic humans through text-to-video. Within the team you’ll have the opportunity to work with different research teams and squads across multiple areas led by our Director of Science, Prof. Vittorio Ferrari, and directly impact our solutions that are used worldwide by over 55,000 businesses.

If you have seen the full ML lifecycle from ideation through implementation, testing and release, and you have a passion for large data, large model training and building solutions with clean code, this is your chance. This is an opportunity to work for a company that is impacting businesses at a rapid pace across the globe.


Apply

Location Mountain View, CA


Gatik is thrilled to be at CVPR! Come meet our team at booth 1831 to talk about how you could make an impact at the autonomous middle mile logistics company redefining the transportation landscape.

Who we are: Gatik, the leader in autonomous middle mile logistics, delivers goods safely and efficiently using its fleet of light & medium-duty trucks. The company focuses on short-haul, B2B logistics for Fortune 500 customers including Kroger, Walmart, Tyson Foods, Loblaw, Pitney Bowes, Georgia-Pacific, and KBX; enabling them to optimize their hub-and-spoke supply chain operations, enhance service levels and product flow across multiple locations while reducing labor costs and meeting an unprecedented expectation for faster deliveries. Gatik’s Class 3-7 autonomous box trucks are commercially deployed in multiple markets including Texas, Arkansas, and Ontario, Canada.

About the role:

We're currently looking for a tech lead with specialized skills in LiDAR, camera, and radar perception technologies to enhance our autonomous driving systems' ability to understand and interact with complex environments. In this pivotal role, you'll be instrumental in designing and refining the ML algorithms that enable our trucks to safely navigate and operate in complex, dynamic environments. You will collaborate with a team of experts in AI, robotics, and software engineering to push the boundaries of what's possible in autonomous trucking.

What you'll do: - Design and implement cutting-edge perception algorithms for autonomous vehicles, focusing on areas such as sensor fusion, 3D object detection, segmentation, and tracking in complex dynamic environments - Design and implement ML models for real-time perception tasks, leveraging deep neural networks to enhance the perception capabilities of self-driving trucks - Lead initiatives to collect, augment, and utilize large-scale datasets for training and validating perception models under various driving conditions - Develop robust testing and validation frameworks to ensure the reliability and safety of the perception systems across diverse scenarios and edge cases - Conduct field tests and simulations to validate and refine perception algorithms, ensuring robust performance in real-world trucking routes and conditions - Work closely with the data engineering team to build and maintain large-scale datasets for training and evaluating perception models, including the development of data augmentation techniques

**Please click on the Apply link below to see the full job description and apply.


Apply

London


Who are we?

Our team is the first in the world to use autonomous vehicles on public roads using end-to-end deep learning, computer vision and reinforcement learning. Leveraging our multi-national world-class team of researchers and engineers, we’re using data to learn more intelligent algorithms to bring autonomy for everyone, everywhere. We aim to be the future of self-driving cars, learning from experience and data.

Where you’ll have an impact

We are currently looking for people with research expertise in AI applied to autonomous driving or similar robotics or decision making domain, inclusive, but not limited to the following specific areas:

Foundation models for robotics Model-free and model-based reinforcement learning Offline reinforcement learning Large language models Planning with learned models, model predictive control and tree search Imitation learning, inverse reinforcement learning and causal inference Learned agent models: behavioral and physical models of cars, people, and other dynamic agents You'll be working on some of the world's hardest problems, and able to attack them in new ways. You'll be a key member of our diverse, cross-disciplinary team, helping teach our robots how to drive safely and comfortably in complex real-world environments. This encompasses many aspects of research across perception, prediction, planning, and control, including:

How to leverage our large, rich, and diverse sources of real-world driving data How to architect our models to best employ the latest advances in foundation models, transformers, world models, etc. Which learning algorithms to use (e.g. reinforcement learning, behavioural cloning) How to leverage simulation for controlled experimental insight, training data augmentation, and re-simulation How to scale models efficiently across data, model size, and compute, while maintaining efficient deployment on the car You also have the potential to contribute to academic publications for top-tier conferences like NeurIPS, CVPR, ICRA, ICLR, CoRL etc. working in a world-class team to achieve this.

What you’ll bring to Wayve

Thorough knowledge of and 5+ years applied experience in AI research, computer vision, deep learning, reinforcement learning or robotics Ability to deliver high quality code and familiarity with deep learning frameworks (Python and Pytorch preferred) Experience leading a research agenda aligned with larger goals Industrial and / or academic experience in deep learning, software engineering, automotive or robotics Experience working with training data, metrics, visualisation tools, and in-depth analysis of results Ability to understand, author and critique cutting-edge research papers Familiarity with code-reviewing, C++, Linux, Git is a plus PhD in a relevant area and / or track records of delivering value through machine learning are a big plus. What we offer you

Attractive compensation with salary and equity Immersion in a team of world-class researchers, engineers and entrepreneurs A unique position to shape the future of autonomy and tackle the biggest challenge of our time Bespoke learning and development opportunities Relocation support with visa sponsorship Flexible working hours - we trust you to do your job well, at times that suit you and your time Benefits such as an onsite chef, workplace nursery scheme, private health insurance, therapy, daily yoga, onsite bar, large social budgets, unlimited L&D requests, enhanced parental leave, and more!


Apply

Excited to see you at CVPR! We’ll be at booth 1404. Come see us to talk more about roles.

Our team consists of people with diverse software and academic experiences. We work together towards one common goal: integrating the software, you'll help us build into hundreds of millions of vehicles.

As a Sr. Fullstack Engineer, you will work on our platform engineering team playing a crucial role in enabling our research engineers to fine-tune our foundation models and streamline the machine learning process for our autonomous technology. You will work on developing products that empower our internal teams to maximize efficiency and innovation in our product. Specifically, you will:

  • Build mission-critical tools for improving observability and scaling the entire machine-learning process.
  • Use modern technologies to serve huge amounts of data, visualize key metrics, manage our data inventory, trigger backend data processing pipelines, and more.
  • Work closely with people across the company to create a seamless UI experience.

Apply

San Jose, CA

B GARAGE was founded in 2017 by a Ph.D. graduate from Stanford University. After having spent over five years researching robotics, computer vision, aeronautics, and drone autonomy, the founder and team set their minds on building a future where aerial robots would become an integral part of our daily lives without anyone necessarily piloting them. Together, our common goal is to redefine the user experience of drones and to expand the horizon for the use of drones.

Roles and Responsibilities

Design and develop perception for aerial robot and inventory recognition for warehouses by leveraging computer vision and deep learning techniques

Aid the computer vision team to deliver prototype and product in a timely manner

Collaborate with other teams within the company

Minimum Qualifications

M.S. degree in computer science, robotics, electrical engineering, or other engineering disciplines

10+ years of experience with computer vision and machine learning

Proficient in image processing algorithms and multiple view geometry using camera

Experience with machine learning architectures for object detection, segmentation, text recognition etc.

Proficient with ROS, C++, and Python

Experience with popular computer vision and GPU frameworks/libraries (e.g., OpenCV,TensorFlow, PyTorch, CUDA, cuDNN etc.)

Proficient in containerization technologies (Docker, Kubernetes) and container orchestration technologies

Experience in cloud computing platforms (AWS, GCP, etc.)

Experience with robots operating on real-time onboard processing

Self-motivated person who thrives in a fast-paced environment

Good problem solving and troubleshooting skills

Legally authorized to work in the United States

Optional Qualifications

Ph.D. degree in computer science, robotics, electrical engineering, or other engineering disciplines

Experience with scene reconstruction, bundle adjustment and factor graph optimization libraries

Experience with Javascript and massively parallel cloud computing technologies involving Kafka, Spark, MapReduce

Published research papers in CVPR, ICCV, ECCV, ICRA, IROS, etc.

Company Benefits

Competitive compensation packages

Medical, dental, vision, life insurance, and 401(k)

Flexible vacation and paid holidays

Complimentary lunches and snacks

Professional development reimbursement (online courses, conference, exhibit, etc.)

B GARAGE stands for an open and respectful corporate culture because we believe diversity helps us to find new perspectives.

B GARAGE ensures that all our members have equal opportunities – regardless of age, ethnic origin and nationality, gender and gender identity, physical and mental abilities, religion and belief, sexual orientation, and social background. We always ensure diversity right from the recruitment stage and therefore make hiring decisions based on a candidate’s actual competencies, qualifications, and business needs at the point of the time.


Apply

Location New York, NY Seattle, WA Boston, MA


Description Climate Pledge Friendly helps customers discover and shop for products that are more sustainable. We partner with trusted sustainability certifications to highlight products that meet strict standards and help preserve the natural world. By shifting customer demand towards more sustainable products, we incentivize selling partners to build better selection, creating a virtuous cycle that yields significant environmental benefit at scale.

We are seeking a Senior Applied Scientist who is not just adept in the theoretical aspects of Machine Learning (ML), Artificial Intelligence (AI), and Large Language Models (LLMs) but also possesses a pragmatic, hands-on approach to navigating the complexities of innovation. You will take the lead in conceptualizing, building, and launching models that significantly improve our shopping experience. A successful applicant will display a comprehensive skill set across machine learning model development, implementation, and optimization. This includes a strong foundation in data management, software engineering best practices, and a keen awareness of the latest developments in distributed systems technology.

You will work with business leaders, scientists, and engineers to translate business and functional requirements into concrete deliverables, including the design, development, testing, and deployment of highly scalable distributed ML models and services. The types of initiatives you can expect to work on include a) personalized recommendations that help our customers find the right sustainable products on each shopping journey, b) automated solutions that combine ML/LLM and data mining to identify products that align with our sustainability goals and resonate with our customers' values, and c) models to measure the environmental and econometric impacts of sustainable shopping.


Apply

The Autonomy Software Metrics team is responsible for providing engineers and leadership at Zoox with tools to evaluate the behavior of Zoox’s autonomy stack using simulation. The team collaborates with experts across the organization to ensure a high safety bar, great customer experience, and rapid feedback to developers. The metrics team is responsible for evaluating the complete end-to-end customer experience through simulation, evaluating factors that impact safety, comfort, legality, road citizenship, progress, and more. You’ll be part of a passionate team making transportation safer, smarter, and more sustainable. This role gives you high visibility within the company and is critical for successfully launching our autonomous driving software.


Apply

Location Multiple Locations


Description Today, more intelligence is moving to end devices, and mobile is becoming the pervasive AI platform. Building on the smartphone foundation and the scale of mobile, Qualcomm envisions making AI ubiquitous—expanding beyond mobile and powering other end devices, machines, vehicles, and things. We are inventing, developing, and commercializing power-efficient on-device AI, edge cloud AI, and 5G to make this a reality.

Job Purpose & Responsibilities As a member of Qualcomm’s ML Systems Team, you will participate in two activities: Development and evolution of ML/AI compilers (production and exploratory versions) for efficient mappings of ML/AI algorithms on existing and future HW Analysis of ML/AI algorithms and workloads to drive future features in Qualcomm’s ML HW/SW offerings

Key Responsibilities: Contributing to the development and evolution of ML/AI compilers within Qualcomm Defining and implementing algorithms for mapping ML/AI workloads to Qualcomm HW Understanding trends in ML network design, through customer engagements and latest academic research, and how this affects both SW and HW design Creation of performance-driven simulation components (using C++, Python) for analysis and design of high-performance HW/SW algorithms on future SoCs Exploration and analysis of performance/area/power trade-offs for future HW and SW ML algorithms Pre-Silicon prediction of performance for various ML algorithms Running, debugging and analyzing performance simulations to suggest enhancements to Qualcomm hardware and software to tackle compute and system memory-related bottlenecks · Successful applications will work in cross-site, cross-functional teams.

Requirements: Demonstrated ability to learn, think and adapt in fast changing environment Detail-oriented with strong problem-solving, analytical and debugging skills Strong communication skills (written and verbal) Strong background in algorithm development and performance analysis is essential The following experiences would be significant assets: Strong object-oriented design principles Strong knowledge of C++ Strong knowledge of Python Experience in compiler design and development Knowledge of network model formats/platforms (eg. Pytorch, Tensorflow, ONNX) is an asset. On-silicon debug skills of high-performance compute algorithms · Knowledge of algorithms and data structures Knowledge of software development processes (revision control, CD/CI, etc.) · Familiarity with tools such as git, Jenkins, Docker, clang/MSVC Knowledge of computer architecture, digital circuits and event-driven transactional models/simulators


Apply

Redmond, Washington, United States


Overview Microsoft Research (MSR) AI Frontiers lab is seeking applications for the position of Senior Research Engineer – Generative AI to join their team in Redmond, WA and New York City, NY.

The mission of the AI Frontiers lab is to expand the pareto frontier of AI capabilities, efficiency, and safety through innovations in foundation models and learning agent platforms. Some of our projects include work on Small Language Models (e.g. Phi, Orca), foundation models for actions (e.g., in gaming, robotics, and Office productivity tools) and Multi-Agent AI (e.g. AutoGen).

We are seeking Senior Research Engineers to join our team and contribute to the advancement of Generative AI and Large Language Models (LLMs) technologies. As a Research Engineer, you will play a crucial role in developing, improving, and exploring the capabilities of Generative AI models. Your work will have a significant impact on the development of cutting-edge technologies, advancing state-of-the-art and providing practical solutions to real-world problems.  

Our ongoing research areas encompass but are not limited to:

Pre-training: especially of language models, action models and multimodal models Alignment and Post-training: e.g., Instruction tuning and reinforcement learning from feedback Continual Learning: Enabling LLMs to evolve and adapt over time and learn from previous experiences human interactions Specialization: Tailoring models to meet application-specific requirements Orchestration and multi-agent systems: automated orchestration between multiple agents incorporating human feedback and oversight

Microsoft Research (MSR) offers a vibrant environment for cutting-edge, multidisciplinary, research, including access to diverse, real-world problems and data, opportunities for experimentation and real-world impact, an open publication policy, and close links to top academic institutions around the world.

Microsoft’s mission is to empower every person and every organization on the planet to achieve more. As employees we come together with a growth mindset, innovate to empower others, and collaborate to realize our shared goals. Each day we build on our values of respect, integrity, and accountability to create a culture of inclusion where everyone can thrive at work and beyond.

Embody our Culture and Values

Responsibilities As a Senior Research Engineer in AI Frontiers, you will design, develop, execute, and implement technology research projects in collaboration with other researchers, engineers, and product groups.

As a member of a word-class research organization, you will be a part of research breakthroughs in the field and will be given an opportunity to realize your ideas in products and services used worldwide.


Apply

Location Mountain View, CA


Description Gatik is thrilled to be at CVPR! Come meet our team at booth 1831 to talk about how you could make an impact at the autonomous middle mile logistics company redefining the transportation landscape.

Who we are: Gatik, the leader in autonomous middle mile logistics, delivers goods safely and efficiently using its fleet of light & medium-duty trucks. The company focuses on short-haul, B2B logistics for Fortune 500 customers including Kroger, Walmart, Tyson Foods, Loblaw, Pitney Bowes, Georgia-Pacific, and KBX; enabling them to optimize their hub-and-spoke supply chain operations, enhance service levels and product flow across multiple locations while reducing labor costs and meeting an unprecedented expectation for faster deliveries. Gatik’s Class 3-7 autonomous box trucks are commercially deployed in multiple markets including Texas, Arkansas, and Ontario, Canada.

About the role: We are seeking passionate Senior/Staff Software Engineers, who have strong fundamentals in software development practices and are experts in C++ language in production-oriented environment. The ideal candidate is a highly experienced C++ developer with a passion for enabling the world's first safe, reliable & efficient network of autonomous vehicles. You will partner with the research and software engineers to design, develop, test and validate AV features for our autonomous fleet.

This role will be onsite at our Mountain View office.

What you'll do: +Design, implement, integrate, and support real-time mission-critical software for the Gatik’s autonomy stack +Work with the research engineers to develop maintainable, testable and robust software designs +Architect and implement solutions to complex issues between components partitioned across the large software stack +Be at the forefront of guiding & ensuring best SDLC practices while contributing to improving the safety in the core autonomy stack +Collaborate with the Infrastructure and DevOps teams for efficient, secure and scalable software delivery to a network of Gatik’s autonomous fleet
+Guide and mentor autonomy researchers and algorithm developers to make sure their components are running efficiently and with optimal compute and memory usage +Review and refine technical requirements and translate them into high-level design & plans to support the development of safe AV technology +Conduct code and design reviews and advise on technical matters

Click the apply button below to see the full job description and apply


Apply

Redmond, Washington, United States


Overview We are seeking a highly skilled and passionate Research Scientist to join our Responsible & OpenAI Research (ROAR) team in Azure Cognitive Services.

As a Research Scientist, you will play a key role in advancing the field of Responsible Artificial Intelligence (AI) to ensure safe releases of the rapidly advancing AI technologies, such as GPT-4, GPT-4V, DALL-E 3 and beyond, as well as to expand and enhance our standalone Azure AI Content Safety Service.

Microsoft’s mission is to empower every person and every organization on the planet to achieve more. As employees we come together with a growth mindset, innovate to empower others, and collaborate to realize our shared goals. Each day we build on our values of respect, integrity, and accountability to create a culture of inclusion where everyone can thrive at work and beyond.

In alignment with our Microsoft values, we are committed to cultivating an inclusive work environment for all employees to positively impact our culture every day.

Responsibilities Conduct cutting-edge research to develop Responsible AI definitions, methodologies, algorithms, and models for both measurement and mitigation of AI risks. Stay abreast of the latest advancements in the field and contribute to the scientific community through publications at top venues. Contribute to the development of Responsible AI policies, guidelines, and best practices and ensure the practical implementation of these guidelines within various AI technology stacks across Microsoft, promoting a consistent approach to Responsible AI. Enable the safe release of new Azure OpenAI Service features, expand and enhance the Azure AI Content Safety Service with new detection technologies. Develop innovative approaches to address AI safety challenges for diverse customer scenarios. Other: Embody our Culture and Values


Apply

Location Palo Alto, CA


Description Amazon is looking for talented Postdoctoral Scientists to join our Stores Foundational AI team for a one-year, full-time research position.

The Stores Foundational AI team builds foundation models for multiple Amazon entities, such as ASIN, customer, seller and brand. These foundation models are used in downstream applications by various partner teams in Stores. Our team also invest in building foundation model for image generation, optimized for product image generation. We leverage the latest development to create our solutions and innovate to push state of the art.

The Postdoc is expected to conduct research and build state-of-the-art algorithms in video understanding and representation learning in the era of LLMs. Specifically, Designing efficient algorithms to learn accurate representations for videos. Building extensive video understanding capabilities including various content classification tasks. Designing algorithms that can generate high-quality videos from set of product images. Improve the quality of our foundation models along the following dimensions: robustness, interpretability, fairness, sustainability, and privacy.


Apply

Location Santa Clara, CA


Description Amazon is looking for a passionate, talented, and inventive Applied Scientists with a strong machine learning background to help build industry-leading Speech, Vision and Language technology.

AWS Utility Computing (UC) provides product innovations — from foundational services such as Amazon’s Simple Storage Service (S3) and Amazon Elastic Compute Cloud (EC2), to consistently released new product innovations that continue to set AWS’s services and features apart in the industry. As a member of the UC organization, you’ll support the development and management of Compute, Database, Storage, Internet of Things (Iot), Platform, and Productivity Apps services in AWS. Within AWS UC, Amazon Dedicated Cloud (ADC) roles engage with AWS customers who require specialized security solutions for their cloud services.

Our mission is to provide a delightful experience to Amazon’s customers by pushing the envelope in Automatic Speech Recognition (ASR), Machine Translation (MT), Natural Language Understanding (NLU), Machine Learning (ML) and Computer Vision (CV).

As part of our AI team in Amazon AWS, you will work alongside internationally recognized experts to develop novel algorithms and modeling techniques to advance the state-of-the-art in human language technology. Your work will directly impact millions of our customers in the form of products and services that make use of speech and language technology. You will gain hands on experience with Amazon’s heterogeneous speech, text, and structured data sources, and large-scale computing resources to accelerate advances in spoken language understanding.

We are hiring in all areas of human language technology: ASR, MT, NLU, text-to-speech (TTS), and Dialog Management, in addition to Computer Vision.


Apply

ASML US, including its affiliates and subsidiaries, bring together the most creative minds in science and technology to develop lithography machines that are key to producing faster, cheaper, more energy-efficient microchips. We design, develop, integrate, market and service these advanced machines, which enable our customers - the world’s leading chipmakers - to reduce the size and increase the functionality of their microchips, which in turn leads to smaller, more powerful consumer electronics. Our headquarters are in Veldhoven, Netherlands and we have 18 office locations around the United States including main offices in Chandler, Arizona, San Jose and San Diego, California, Wilton, Connecticut, and Hillsboro, Oregon.

ASML’s Optical Sensing (Wafer Alignment Sensor and YieldStar) department in Wilton, Connecticut is seeking a Design Engineer to support and develop complex optical/photonic sensor systems used within ASML’s photolithography tools. These systems typically include light sources, detectors, optical/electro-optical components, fiber optics, electronics and signal processing software functioning in close collaboration with the rest of the lithography system. As a design engineer, you will design, develop, build and integrate optical sensor systems.

Role and Responsibilities Use general Physics, Optics, Software knowledge and an understanding of the sensor systems and tools to develop optical alignment sensors in lithography machines Have hands-on sills of building optical systems (e.g. imaging, testing, alignment, detector system, etc.) Have strong data analysis sills to evaluate sensor performance and troubleshooting Leadership:

Lead executing activities for determining problem root cause, execute complex tests, gather data and effectively communicate results on different levels of abstraction (from technical colleagues to high level managers) Lead engineers in various competencies (e.g. software, electronics, equipment engineering, manufacturing engineering, etc.) in support of feature delivery for alignment sensors Problem Solving: Troubleshooting complex technical problems Develop/debug data signal processing algorithms Develop and execute test plans in order to determine problem root cause Communications/Teamwork: Draw conclusions based on the input from different stakeholders Capability to clearly communicate the information on different level of abstraction Programming: Implement data analysis techniques into functioning MATLAB codes Optimization skills GUI building experience Familiarly with LabView and Python Some travel (up to 10%) to Europe, Asia and within the US can be expected


Apply

Mountain View


Who we are Established in 2017, Wayve is a leader in autonomous vehicle technology, driven by breakthroughs in Embodied AI. Our intelligent, mapless, and hardware-agnostic technologies empower vehicles to navigate complex environments effortlessly.

Supported by prominent investors, Wayve is advancing the transition from assisted to fully automated driving, making transportation safer, more efficient, and universally accessible. Join our world-class, multinational team of engineers and researchers as we push the boundaries of frontier AI and autonomous driving, creating impactful technologies and products on a global scale

Where you will have an impact We are looking for an experienced Research Engineer to help us in our journey to scale end-to-end neural networks for autonomous driving. You’ll be working across our research team to build, integrate, test and scale algorithms, tools, and machine learning solutions for autonomous driving.

What you will bring to Wayve 5+ years of software engineering experience in an industrial research environment Passion to work in a team on research ideas that have real world impact Strong software engineering experience in Python and other relevant languages (especially C++ and CUDA) Ideally with direct experience working in at least one of computer vision, robotics, simulation, graphics, large language models Ideally with several years working on large-scale machine learning algorithms and systems BS, MS, or above in Machine Learning, Computer Science, Engineering, or a related technical discipline or equivalent experience

What we offer you The chance to be part of a truly mission driven organisation and an opportunity to shape the future of autonomous driving. Unlike our competitors, Wayve is still relatively small and nimble, giving you the chance to make a huge impact Competitive compensation Fully employer-covered medical, dental and vision insurance! Further benefits such as catered lunch, yummy snacks, and variety of drinks, life insurance, employer contributed retirement account, therapy, yoga, office-wide socials and much more. A dynamic and fast-paced work environment in which you will grow every day - learning on the job, from the brightest minds in our space, and with support for more formal learning opportunities too A culture that is ego-free, respectful and welcoming (of you and your dog) - we even eat lunch together every day This is a full-time role based in our office in California. At Wayve we want the best of all worlds so we operate a hybrid working policy that combines time together in our offices and workshops to fuel innovation, culture, relationships and learning, and time spent working from home. We also operate core working hours so you can be where you need to be for family and loved ones too. Teams determine the routines that work best for them.


Apply