C# Jobs

Harvey

Harvey is transforming professional services by combining frontier agentic AI, an enterprise-grade platform, and deep domain expertise. We are a fast-growing company with strong product-market fit, seeking individuals who want to do the best work of their careers. As a Staff Software Engineer on the Model Infrastructure team, you will lead the design and development of the systems that power every AI request at Harvey. You will partner closely with AI Research, Product Engineering, and Infrastructure teams to build a highly reliable, scalable, observable, and efficient platform.

$236k - $290k

Anthropic

Anthropic's Security Governance, Risk, and Compliance (GRC) team is seeking a Security Controls Assurance Lead to translate regulatory, customer, and voluntary obligations into actionable controls. This role will define control requirements and acceptance criteria for global compliance obligations across the software development lifecycle, partnering with engineering teams to ensure implemented controls meet defined standards. The goal is to build an integrated compliance and risk ecosystem that serves as a trust engine and an independent risk advisor for Anthropic.

Anthropic

As a Research Engineer within Reinforcement Learning, you will collaborate with a diverse group of researchers and engineers to advance the capabilities and safety of large language models. This role blends research and engineering responsibilities, requiring you to both implement novel approaches and contribute to the research direction. You'll work on fundamental research in reinforcement learning, creating 'agentic' models via tool use for open-ended tasks such as computer use and autonomous software generation, improving reasoning abilities in areas such as mathematics, and developing prototypes for internal use, productivity, and evaluation.

Anthropic

Anthropic is building reliable, interpretable, and steerable AI systems to ensure AI is safe and beneficial. The Security Risk team is rebuilding risk management as an engineering function, leveraging automation and AI-native platforms. This role involves identifying, prioritizing, and treating the company's most critical security risks across a broad spectrum of systems, from authorization to cryptography. You will help define the future of risk management for frontier AI companies, with a direct impact on CISO-level decisions and the opportunity to build the underlying AI-native platform. The work is largely greenfield, allowing you to shape the architecture and discipline.

Anthropic

Anthropic is building reliable, interpretable, and steerable AI systems to be safe and beneficial for users and society. The Security Engineering team is crucial in protecting these AI systems and maintaining user trust. This role involves owning and contributing to key areas such as identity and secrets management, developer security and supply chain, infrastructure security, and secure frameworks. You will have the opportunity to define architecture in largely greenfield work, collaborating closely with various teams to ensure the security and integrity of Anthropic's AI development and deployment processes.

Anthropic

As a Research Engineer within Reinforcement Learning, you will collaborate with a diverse group of researchers and engineers to advance the capabilities and safety of large language models. This role blends research and engineering responsibilities, requiring you to both implement novel approaches and contribute to the research direction. You'll work on fundamental research in reinforcement learning, creating 'agentic' models via tool use for open-ended tasks such as computer use and autonomous software generation, improving reasoning abilities in areas such as mathematics, and developing prototypes for internal use, productivity, and evaluation.

Scale AI

Scale AI is seeking a highly skilled and motivated Software Engineer to join our dynamic Public Sector Engineering team. You will play a critical role in supporting Scale’s government customers by scoping and developing onsite solutions. Your expertise will be instrumental in designing and implementing systems that can handle interactions with existing customer systems to help our products integrate into existing customer workflows. We are looking for an exceptional Senior Software Engineer to architect and build the foundational data infrastructure that will serve as the brain of a project ecosystem. You will be responsible for designing highly novel data models and processing pipelines capable of handling massive quantities of output data from complex simulations. At the core of this role is the challenge of building a foundational data ensemble—a unified architecture that seamlessly aggregates, structures, and stages diverse sources of simulation outputs and user inputs. Your systems will manage enormous batch throughput jobs with strict, minimal latency requirements, ensuring that downstream AI systems and language models have the exact context they need to actionably reason over complex, multi-dimensional scenarios.

$216k - $300k

Together AI

The Turbo Research team focuses on making post-training and reinforcement learning for large language models efficient, scalable, and reliable. This work intersects RL algorithms, inference systems, and large-scale experimentation, where inference costs significantly impact training efficiency and the practicality of learning algorithms. As a research intern, you will investigate RL and post-training methods whose performance and scalability are closely tied to inference behavior, co-designing algorithms and systems. Projects aim to enable new experimental regimes, including larger models, longer rollouts, and more complex evaluations, by re-evaluating the interaction between inference, scheduling, and training.

pika

We are seeking a Staff/Lead Software Engineer, AI Infrastructure, to play a critical role in building and scaling the core infrastructure that powers Pika’s AI capabilities. In this position, you will lead the design and implementation of GPU infrastructure, AI model serving APIs, and general AI infrastructure execution, enabling cutting-edge machine learning features that drive our products. You will be responsible for architecting robust, distributed systems optimized for high-performance AI workloads, large-scale GPU orchestration, and low-latency, reliable API serving. Your work will directly impact the way users experience and interact with generative AI at scale. As a senior technical leader, you’ll also mentor engineers, drive best practices, and set the technical vision for AI infrastructure at Pika.

Together AI

Together.ai is building state-of-the-art infrastructure for efficient and scalable inference of large language models (LLMs). The company's mission is to optimize inference frameworks, algorithms, and infrastructure to push the boundaries of performance, scalability, and cost-efficiency. They are seeking an Inference Frameworks and Optimization Engineer to design, develop, and optimize distributed inference engines for multimodal and language models at scale. This role will focus on low-latency, high-throughput inference, GPU/accelerator optimizations, and software-hardware co-design, ensuring efficient large-scale deployment of LLMs and vision models. This position offers a unique opportunity to shape the future of LLM inference infrastructure and ensure scalable, high-performance AI deployment across diverse applications.

$160k - $230k

Together AI

Together AI is seeking an ML Engineer to develop systems and APIs for customer inference and fine-tuning of LLMs. The ideal candidate will have experience implementing runtime systems for large-scale AI/ML model inference, including the largest LLMs. This role involves designing and building production systems for reliability and performance at scale, partnering with cross-functional teams, and improving system efficiency and stability.

$160k - $220k

Together AI

Together AI is a research-driven artificial intelligence company focused on lowering the cost of modern AI systems. This role is part of a team dedicated to enabling custom models and dedicated inference on Together's platform. The team is responsible for building a container platform, optimizing autoscaling, minimizing cold starts, achieving the best end-to-end model performance, and providing a best-in-class developer experience with great tooling. The work often involves video or audio generation across the stack, including CUDA kernels, PyTorch optimization, inference engines, container orchestration, and queueing theory.

$160k - $250k

Scale AI

Scale's Global Public Sector team is focused on using AI to address critical challenges facing the public sector worldwide. We create custom AI applications impacting millions of citizens, generate high-quality training data for national LLMs, and provide upskilling and advisory services to spread AI's impact. As a DevOps Engineer, you will design and develop core platforms and software systems, supporting orchestration, data abstraction, data pipelines, identity & access management, security tools, and underlying cloud infrastructure. We are enabling the public sector to transform operations and better serve citizens through cutting-edge technology.

Scale AI

As a Software Engineer on the Machine Learning Infrastructure team, you will build the "Operating System" for our large-scale GPU clusters. You will architect a high-performance training platform that handles the immense complexity of multi-thousand GPU workloads, ensuring every cycle is used efficiently. Your work directly determines the velocity at which our researchers can train and iterate on the world’s most advanced models. The ideal candidate is a systems expert who thrives on solving the orchestration, networking, and reliability challenges that emerge at massive scale. You will partner closely with researchers to build a seamless, resilient environment that transforms raw compute into breakthrough AI.

$216k - $270k

Scale AI

Scale's Robotics business unit is focused on solving the data bottleneck in Physical AI across Robotics, Autonomous Vehicles, and Computer Vision. In this role, you will be a key contributor building production systems for robotics data collection, model training pipelines, and evaluation infrastructure. You will have the opportunity to own critical parts of our robotics platform, work directly with cutting-edge robotics and AV customers, and shape the future of embodied AI systems.

Scale AI

Scale's Physical AI business unit is focused on solving data bottlenecks in Robotics, Autonomous Vehicles, and Computer Vision. This role involves applied research and developing ML pipelines for processing, training, and fine-tuning data collected by Scale, with an emphasis on optimizing algorithms and pipelines for efficient GPU execution in the cloud. You will advance research, shape Scale's offerings, and expand the frontier of data and model evaluation for Physical AI. As an ML Systems Engineer, you will design and build platforms for scalable, reliable, and efficient serving of foundation models tailored for physical agents, powering both internal research and external customer use cases.

$249k - $311k

Scale AI

Scale's Robotics business unit is dedicated to solving the data bottleneck in Physical AI across Robotics, Autonomous Vehicles, and Computer Vision. In this role, you'll be a key contributor building production systems for robotics data collection, model training pipelines, and evaluation infrastructure. You'll have the opportunity to own critical parts of our robotics platform, work directly with cutting-edge robotics and AV customers, and shape the future of embodied AI systems.

$180k - $225k

Scale AI

As a Software Engineer on the ML Infrastructure team, you will design and build platforms for scalable, reliable, and efficient serving of LLMs. Our platform powers cutting-edge research and production systems, supporting both internal and external use cases across various environments. You'll work in a highly collaborative environment, bridging research and engineering to deliver seamless experiences to our customers and accelerate innovation across the company.

$216k - $270k

Scale AI

Scale's Global Public Sector team is seeking Applied AI Engineers to build custom, end-to-end AI applications for public sector clients worldwide. This role involves leveraging the latest AI advancements to create impactful solutions, generate high-quality training data for national LLMs, and contribute to upskilling initiatives. You will work on developing and fine-tuning sophisticated models for real-world use cases, aiming to transform public sector operations and enhance citizen services through cutting-edge technology. Join a rapidly expanding team dedicated to shaping the future of AI in the public sector.

Mistral AI

Mistral AI is seeking passionate and skilled software engineers to join our Warsaw-based Context Engine team. You will be instrumental in building and enhancing Mistral's agent harness, which is crucial for delivering production-grade knowledge processing and directly influences how users interact with our AI platform. The role involves developing reliable, high-performance backend systems and APIs that serve millions of users and developers, ultimately making the user and developer experience more engaging, efficient, and intuitive. We are looking for engineers at mid to senior staff levels who are eager to learn, collaborate, and ship impactful products.