Python Jobs

Reflection ai

Reflection is a research lab dedicated to making intelligence open and accessible. As a member of the Data Team, you will ensure the data used to train and evaluate our models meets high standards for quality, reliability, and impact. You will work closely with world-class researchers on post-training teams to translate abstract notions of "good data" into concrete, measurable standards that scale across large data campaigns. This role requires engineers who combine strong engineering fundamentals with a deep curiosity about data quality and its impact on model behavior.

LangChain is seeking a Senior Backend Engineer to join the LangSmith team, which focuses on building the core platform for observability, evaluation, and production reliability of AI systems. In this role, you will be responsible for developing the backend systems that power LangChain's observability and evals platform, enabling developers to monitor and evaluate their AI applications at scale. While the primary focus is on backend development, experience with full-stack or frontend engineering, performance tuning, and debugging production issues will be highly beneficial.

$175k - $240k

Baseten is seeking Software Engineers to join their team in a specialized, high-impact role at the intersection of high-performance computing (HPC) and Large Language Model (LLM) engineering. This position involves not only building automated performance monitoring and diagnostic tools for next-generation AI infrastructure but also defining the roadmap, driving key technical decisions, and taking full ownership of the future direction of this work. The role offers the opportunity to shape the platform that engineers use to deploy cutting-edge AI models into production.

OpenAI

As an Applied AI Engineer, you will partner directly with leading organizations to design, build, and deploy AI systems that deliver measurable business outcomes. You will combine deep technical judgment, hands-on engineering, and customer leadership to take ambitious ideas from use-case selection and architecture through prototyping, evaluation, production launch, and scale. You will write and debug code, build evaluation systems, resolve complex integrations, and guide decisions involving model behavior, reliability, latency, cost, safety, security, governance, and operational readiness. Success is measured by production systems, sustained adoption, and meaningful customer impact. This is a rare opportunity to work on consequential real-world deployments at the frontier of AI while directly influencing how OpenAI’s products evolve.

Replit

Replit is seeking a highly technical, data-driven Growth Engineer to help scale its product and expand key user metrics across acquisition, activation, retention, and monetization. This role sits at the intersection of engineering, product, and marketing, leveraging code, experimentation, and analytics to uncover opportunities and deliver measurable impact. The ideal candidate will drive experimentation and optimization by designing, implementing, and analyzing A/B and multivariate tests, and identify bottlenecks in user funnels to improve conversion rates. They will also build and scale growth-oriented product features like onboarding flows and referral systems, ensuring scalable code and infrastructure. Collaboration with data teams for tracking, dashboards, and user behavior analysis, along with leveraging SQL and analytics tools, is crucial. The role involves close partnership with product managers, designers, marketers, and data scientists to align on growth goals and translate business objectives into technical requirements.

Mistral AI

Mistral AI is democratizing AI through high-performance, optimized, open-source models and products. We are a dynamic, collaborative team passionate about AI's potential to transform society, with teams distributed globally. We are seeking an AI Engineer to join a product team, focusing on improving AI-powered features through rigorous evaluation, prompt and orchestration design, and rapid experimentation. You will own your domain's AI quality end-to-end, defining, measuring, and shipping improvements in collaboration with our Science team.

OpenAI

We are seeking a Backend Software Engineer with experience in ML/LLM-heavy domains to design and build an "evals" infrastructure. This role is critical for measuring the quality of OpenAI's support automation and involves building robust systems and backend services that form the foundation for knowledge creation, access, and application across OpenAI. You will collaborate closely with Data Science and Research partners to design and build evaluations at scale, focusing on creating reliable, reproducible, and extendable eval pipelines and infrastructure for continuous monitoring.

Harvey

Harvey is transforming legal and professional services by combining AI, an enterprise platform, and domain expertise. This is a chance to help build a generational company at an inflection point, with strong product-market fit and investor support, as we scale rapidly and define a new category. The team moves fast, takes ownership, and is committed to the mission, valuing decisiveness, simplicity, and continuous improvement. As a Backend Platform Engineer, you will build and operate the cohesive backend platform supporting all Harvey services. This role focuses on designing and implementing shared frameworks and libraries to abstract common concerns, enhance developer experience, and improve reliability and performance across teams, enabling product engineers to focus on shipping features.

$238k - $290k

Reflection ai

Reflection is a research lab dedicated to making intelligence open and accessible. We build open models that empower individuals to control their intelligence and shape the future of AI. In this role, you will be instrumental in advancing AI innovation by focusing on data, which is critical for developing capabilities like agentic tool use, long-horizon reasoning, and robust safety alignment. You will collaborate with world-class researchers to design and implement our data strategy, directly influencing the performance of our AI models.

Replit

Replit is seeking a Staff Software Engineer specializing in monetization systems to lead this critical area of the company. This role offers a direct line to business impact while ensuring a positive user experience for billing and payment processes. The ideal candidate will build reliable, scalable billing systems and abstractions, translating complex pricing into intuitive user interfaces. This position is crucial for democratizing software development by removing barriers to application creation.

Reflection ai

Reflection is a research lab dedicated to making intelligence open and accessible. We are seeking a core member for our Applied AI team to lead Forward Deployed Engineering efforts with enterprise customers. This role involves translating advanced AI research into high-impact, real-world applications, owning the technical strategy and delivery of agentic systems from discovery to production launch.

Cohere

Cohere is seeking a Member of Technical Staff in Data Analysis and Evaluation to ensure the quality, reliability, and performance of our large language models (LLMs). This role involves designing and conducting data collection tasks, assessing dataset quality, and analyzing model robustness and generalisability. You will collaborate with researchers, engineers, and data annotators to drive data-driven decisions and enhance AI system effectiveness. The position requires expertise in statistics, experimental design, and machine learning to ensure high-quality data and reliable model performance across diverse scenarios, contributing to Cohere's mission of advancing AI.

Mistral AI

Mistral AI is seeking an AI Deployment Strategist to drive the adoption and deployment of their AI solutions. This role involves working closely with customers from strategic vision to production implementation, sitting at the intersection of business strategy, AI innovation, and hands-on deployment. You will partner with senior executives to design AI roadmaps, collaborate with the Applied AI team to deliver solutions in production, and ensure seamless transitions from presales to postsales, directly contributing to customer success by bridging the gap between strategy and execution. This position is ideal for individuals who thrive in a fast-paced environment, enjoy solving complex business challenges, and are passionate about turning AI potential into real-world impact.

We are seeking an IT Engineer to manage the employee technology experience within our New York or London office, while also contributing to the scaling of Cognition's global IT operations. This role is the primary IT point of contact for the office, ensuring employees have secure and reliable technology and receive prompt support. The position also involves enhancing IT operations through the development of durable tooling, automation, and AI-enabled workflows to streamline recurring tasks. Ideal candidates will possess in-depth knowledge in two to three IT disciplines and a desire to explore new areas.

Mistral AI

Mistral AI is seeking early-career software engineers, including new graduates or those with up to 1-2 years of experience, to join their software engineering teams. In this role, you will contribute to building and enhancing the core systems that power Mistral's products, such as AI Studio and Applications, as well as supporting operations like SRE, data, and security. You will play a key part in shaping how users and developers interact with the AI platform at scale, working closely with experienced engineers who will mentor and support your growth. This is an opportunity for enthusiastic graduates to learn, collaborate, and deliver impactful products in a fast-paced environment.

Perplexity is looking for a hands-on Software Engineer to develop and enhance the software, automations, and systems that support our security operations. This role involves engineering security tools and internal AI-driven agents to improve detection, response, vulnerability management, and the overall security posture of our products and infrastructure.

Harvey

Harvey is transforming legal and professional services by combining frontier agentic AI, an enterprise-grade platform, and deep domain expertise. We are a fast-scaling company with strong product-market fit, seeking ambitious individuals to help build a generational company. Our team operates with intensity, ownership, and a commitment to our mission, valuing decisiveness, simplicity, and continuous improvement. As a Software Engineer on the Site Reliability team, you will ensure the reliability, scalability, and performance of our legal AI platform, owning the systems that keep our platform fast, secure, and always on. Your work will be crucial in maintaining platform resilience as we grow across 50+ regions.

$200k - $260k

Harvey

Why Harvey At Harvey, we’re transforming how legal and professional services operate. By combining frontier agentic AI, an enterprise-grade platform, and deep domain expertise, we’re reshaping how critical knowledge work gets done for decades to come. This is a rare chance to help build a generational company at a true inflection point. With 1500+ customers in 60+ countries, strong product-market fit, and world-class investor support, we’re scaling fast and defining a new category in real time. The work is ambitious, the bar is high, and the opportunity for growth — personal, professional, and financial — is unmatched. Our team moves fast, takes ownership, and is deeply committed to the mission — operating with intensity, staying close to our customers, and pushing each other for excellence. We live by three values: Decisiveness, Simplicity, and Job's Not Finished. We act quickly on clear judgment over perfect information, we believe simplicity is what scales, and we're never satisfied with where we are. If you want to do the best work of your career alongside people who share that drive, we'd love to build with you. At Harvey, the future of professional services is being written today — and we’re just getting started. Role Overview As a Staff Software Engineer on the Site Reliability team at Harvey, you will ensure the reliability, scalability, and performance of our legal AI platform. You’ll join a high-leverage team that sits at the intersection of infrastructure and product, owning the systems that keep our platform fast, secure, and always on. From scaling across 50+ regions to automating mission-critical operations, your work will ensure that Harvey remains resilient as we grow. If you’re passionate about building robust systems and reducing complexity through automation, we’d love to work with you.  This role is based in San Francisco, CA. We use an in-person work model and offer relocation assistance to new employees. What You’ll Do - Design, implement, and manage monitoring, alerting, and infrastructure resources (compute, storage, networking) across 50+ global regions - Lead incident management processes, including postmortems, root cause analyses, and driving actionable improvements - Automate operational tasks and workflows, building tools and processes for capacity planning, graceful rollouts, and safe data access to maintain high reliability and reduce manual intervention - Establish best practices for security, compliance, and reliability and collaborate across teams to drive these principles throughout the software lifecycle - Optimize infrastructure costs through strategic capacity planning and build-versus-buy decisions while maintaining system performance, reliability, and functionality - Provide technical mentorship and leadership, promoting best practices and fostering team growth What You Have  - 10+ years of experience in Site Reliability Engineering or similar roles supporting production environments, with proven ability to mentor and guide technical teams - Expertise in infrastructure as code(IaC) tools (Pulumi, Terraform, CloudFormation, etc.) - Deep familiarity with observability tools (Datadog, Sentry, etc.) and incident response practices (PagerDuty, IncidentIO, etc.) - Proficiency with cloud infrastructure platforms (Azure, GCP, AWS, etc.) - Strong programming skills (Python, Bash, Go, or similar languages) - Proven track record of diagnosing complex system problems and implementing durable solutions - Solid understanding of CI/CD, Kubernetes, containerization, networking, databases, and cloud security principles - Excellent problem-solving skills, meticulous attention to detail, and a commitment to operational excellence Compensation Range $238,000 - $290,000 USD Depending on your location, an Applicant Privacy Notice may apply to you. You can find all of our Applicant Privacy Notices [here]. #LI-AN2 Harvey is an equal opportunity employer and does not discriminate on the basis of race, gender, sexual orientation, gender identity/expression, national origin, disability, age, genetic information, veteran status, marital status, pregnancy or related condition, or any other basis protected by law. We are committed to providing reasonable accommodations to applicants with disabilities, and requests can be made by emailing [email protected]

$238k - $290k

Mistral AI

Mistral AI is seeking a Technical Lead, Applied AI to drive the technical strategy, execution, and delivery of complex AI solutions for enterprise customers. In this role, you will lead project teams of Applied AI Engineers, ensuring the successful deployment of Mistral AI products and the development of high-impact, scalable AI use cases. You will act as the primary technical point of contact for strategic customers, guiding them through the entire lifecycle from pre-sales to post-implementation, while collaborating closely with research, product, and engineering teams to shape the future of our offerings. As a Technical Lead, you will bridge the gap between cutting-edge AI research and real-world enterprise applications, ensuring our solutions are robust, scalable, and aligned with both customer needs and Mistral’s technological vision.

Cohere

Cohere is seeking a Senior Machine Learning Engineer specializing in synthetic data to develop and manage the synthetic data pipeline crucial for advanced language models. This role involves end-to-end management of synthetic data, including pipeline optimization, data analysis and generation, and conducting data ablations and model evaluations. You will transform diverse web and code data using generative models to enhance token efficiency and model quality, bridging research and engineering to improve throughput and accelerator utilization. This position is key to Cohere's mission of delivering efficient and reliable language capabilities and driving innovation in natural language processing.