Software Engineer II - Reinforcement Learning Environments

PhD Internship: Machine Learning EngineerAbout HandshakeAt Handshake, we are revolutionizing career development in the AI economy. With a network of over 20 million skilled professionals and partnerships with 1,600 educational institutions and 1 million employers, including all Fortune 50 companies, Handshake is the go-to platform for career exploration, hiring, and skill enhancement. Join us as we help individuals transition from freelance opportunities to internships and full-time roles, connecting talent with opportunities at every career stage.Our unique position in the market has catalyzed impressive growth, with projections indicating that we will triple our ARR by 2025.Why You Should Join Handshake Now:Contribute to the evolution of careers in the AI economy on a global scale, making a tangible impact.Collaborate with top AI labs, Fortune 500 companies, and prestigious educational institutions.Play a key role in building a fast-growing business targeting multi-billion-dollar revenues.Position OverviewAs a Machine Learning Engineering Intern, you will be instrumental in crafting intelligent product experiences that assist students in discovering and securing opportunities. Your responsibilities will encompass search algorithms, recommendations, and matching systems that enhance job exploration on Handshake.This internship will provide you with practical experience in developing, assessing, and deploying machine learning models within a production environment, as well as insights into the design, optimization, and maintenance of large-scale ML systems.This is a paid, full-time summer internship with two cohort options:May 18 – August 7, 2026June 15 – September 4, 2026Key Responsibilities:Collaborate with experienced engineers and data scientists to develop machine learning models that enhance product features and improve user experience.Engage in experimentation, model evaluation, and performance monitoring.Participate in technical discussions, brainstorming sessions, and team reviews.Document methodologies and findings to facilitate knowledge sharing and long-term improvements to systems.QualificationsEssential Qualifications:Currently pursuing a PhD in Computer Science, Data Science, Machine Learning, or a related field.Strong programming skills in Python and familiarity with machine learning libraries (e.g., TensorFlow, PyTorch).Experience with data analysis and statistical modeling.Excellent problem-solving abilities and analytical thinking.Strong communication skills and ability to work collaboratively in a team environment.

Join Handshake as a Machine Learning Engineer I, where you will have the opportunity to work on cutting-edge machine learning projects that drive our innovative solutions. Collaborate with a talented team to develop algorithms and models that enhance our product offerings and improve user experiences.

Join Handshake as an Associate Machine Learning Engineer and embark on an exciting journey in the world of artificial intelligence and machine learning. In this role, you will collaborate with a talented team to develop innovative solutions that leverage cutting-edge technologies. You'll have the opportunity to contribute to real-world projects, enhancing your skills while driving impactful results.

Join Handshake as a Machine Learning Research Scientist and contribute to groundbreaking projects that leverage advanced algorithms and data analysis to drive innovation. In this role, you will collaborate with a dynamic team to design, implement, and evaluate machine learning models that enhance our products and services. Your expertise will be pivotal in unlocking new insights from data, improving user experiences, and shaping the future of our technology.

Pinterest is looking for a PhD Fall Machine Learning Intern with a focus on visual, multimodal, and recommender systems. This internship centers on supporting advanced machine learning projects alongside skilled engineers and researchers. Role overview The position involves contributing to ongoing research and development in machine learning. Interns will have the chance to work on projects that explore visual understanding and recommendation technologies, learning from experienced team members throughout the process. Collaboration Expect to work closely with engineers and researchers who specialize in machine learning. The environment encourages sharing ideas and building solutions that impact Pinterest’s products. Locations San Francisco, CA, US Palo Alto, CA, US Seattle, WA, US New York, NY, US

About NationGraphAt NationGraph, we are revolutionizing the accessibility and usability of public sector data for businesses targeting municipalities, state agencies, educational institutions, and specialized districts. Our advanced data intelligence engine extracts actionable insights from millions of public sector sources, empowering organizations to make informed decisions. Established in 2024, our mission is to democratize information, ensuring that public data is genuinely accessible to everyone. Discover more at nationgraph.comOur TeamComprises seasoned entrepreneurs who have successfully built, scaled, and exited multiple companies.Developed robust software infrastructure capable of processing billions in transactions.Supported by top-tier venture capitalists and seasoned operating partners with a track record of investing in and nurturing iconic brands.Role OverviewDesign and implement end-to-end machine learning pipelines.Extract and mine data from various online sources through large-scale web crawling and scraping techniques to enhance our models and insights.Convert unstructured text data into structured knowledge using natural language processing (NLP), entity recognition, and bespoke models.Develop and refine text classification models to systematically organize intricate datasets.Enhance retrieval-augmented generation (RAG) systems utilized in our product offerings.Drive our data strategy by identifying and integrating new data sources.Tackle open-ended technical challenges, fostering a culture of learning and collaboration within the team.Primarily utilize Python and SQL for development.QualificationsA strong quantitative background in fields such as computer science, physics, mathematics, or engineering.Solid foundation in mathematics and statistics.A PhD in a quantitative discipline.Expertise in Python programming.Proactive ownership mentality with the ability to address complex technical challenges to create commercial value.A genuine enthusiasm for continuous learning, growth, and uncovering insights from complex datasets.Strong problem-solving, communication, and collaboration abilities in a dynamic work environment.

Founded in 2007, Airbnb has transformed the way people travel, connecting over 5 million hosts with more than 2 billion guests worldwide. Our platform enables unique stays and experiences that promote authentic community connections. Join Our Team:We are looking for a Machine Learning Engineering Intern to be part of our 2026 Summer Internship Program.At Airbnb, machine learning is at the forefront of our innovation, addressing challenges in areas such as search ranking, payment security, fraud prevention, and user growth, all while ensuring a seamless user experience. Our team actively contributes to the ML community by publishing insightful articles and research at leading conferences. Explore our work on Medium: https://medium.com/airbnb-engineering/tagged/machine-learningThe Search Relevance and Personalization team focuses on developing cutting-edge algorithms and personalizing user experiences across various product surfaces. Our team of over 30 ML Engineers is dedicated to experimentation, frequently conducting A/B tests to enhance the relevance of our offerings. We also engage in applied research, regularly sharing our findings at prominent conferences such as KDD, CIKM, and WSDM. Your Impact:As a Machine Learning Intern, you will be immersed in a collaborative environment where you'll lead a project that aligns with your technical interests and career goals. Your project will explore innovative applications of AI agents to enhance Airbnb's search and discovery functionalities. Internship Experience:During your internship, you will be part of a dynamic team tackling significant challenges. Expect support, mentorship, and engaging activities that will enrich your learning experience and allow you to make a tangible impact on our products as we redefine connection, belonging, and travel.Take ownership of a capstone project from concept to completion.Collaborate with experienced engineers and leaders in the field.

About HandshakeHandshake serves as the premier career network tailored for the burgeoning AI economy. Trusted by 20 million knowledge workers, 1,600 educational institutions, and a million employers—including every Fortune 50 company—Handshake is pivotal in facilitating career discovery, hiring, and upskilling, from freelance AI training roles to internships and full-time positions. Our unique value proposition has led to exceptional growth, with our Annual Recurring Revenue (ARR) projected to triple by 2025.Why You Should Join Handshake Now:Influence the evolution of careers within the AI economy on a global scale, making a tangible impact for your community.Collaborate with elite AI labs, Fortune 500 partners, and leading educational institutions.Join a team led by professionals from Scale AI, Meta, xAI, Notion, Coinbase, and Palantir, among others.Contribute to building a rapidly expanding business projected to generate billions in revenue.About the RoleThe Senior Engineering Manager at Handshake AI will oversee a vital product and platform engineering team responsible for developing systems that seamlessly integrate human expertise into AI development workflows. This team manages essential infrastructure that links talent networks, data operations, and research requirements into scalable, reliable, and high-quality platforms. You will play a pivotal role at the crossroads of engineering, product, and operations, ensuring our systems can accommodate rapid growth, intricate workflows, and cutting-edge AI partners. You will lead a team of approximately 9 engineers and will be expected to expand leadership capacity, including managing another engineering manager, as we scale.Location: San Francisco, CA. This position requires in-office attendance, 5 days/week (no remote or hybrid options).Your ResponsibilitiesLead, recruit, and nurture a high-performing engineering team focused on developing core product and platform infrastructure.Define and execute the roadmap in close collaboration with Product, Research, and Operations teams.Drive the architectural and technical strategy for scalable, reliable, and extensible systems.Develop modular platforms that facilitate quick launches for new domains, workflows, and partners.Enhance engineering standards across reliability, observability, performance, and data integrity.Cultivate a culture of ownership, accountability, and continuous improvement within the team.

About HandshakeHandshake is the premier career network tailored for the AI economy, serving over 20 million knowledge workers, 1,600 educational institutions, and 1 million employers, including all Fortune 50 companies. Our platform is trusted for career discovery, recruitment, and professional development, facilitating opportunities ranging from freelance AI training roles to full-time positions. Our unique value proposition is driving remarkable growth, with an expectation to triple our Annual Recurring Revenue (ARR) by 2025.Why is now the best time to join Handshake?Be a key player in shaping the future of careers within the AI economy, creating tangible impacts for your community.Collaborate closely with leading AI research labs, Fortune 500 partners, and top-tier educational institutions.Join a team enriched by leaders from renowned organizations such as Scale AI, Meta, xAI, Notion, Coinbase, and Palantir.Contribute to building a rapidly growing business projected to generate billions in revenue.About the RoleWe are looking for an experienced Senior Engineering Manager to lead our dynamic Reinforcement Learning Environments (RLE) team.The RLE team creates innovative sandbox environments where cutting-edge AI models can learn comprehensive, end-to-end workflows. These environments replicate real-world professional fields such as software engineering, finance, and legal research, complete with realistic tools, constraints, and feedback mechanisms. Rather than relying on static examples, models engage in practical tasks: navigating multi-step processes, utilizing domain-specific tools, managing uncertainty, and optimizing for real-world results.Researchers leverage these environments and the data produced to train state-of-the-art models using reinforcement learning based on execution—focusing not just on predictions but on task fulfillment, quality, and resilience in complex workflows.As a Senior Engineering Manager, you will define the technical direction and long-term strategy of this vital platform. You will lead a growing team of 8-9 engineers and are expected to manage an Engineering Manager in the near future. This strategic role intersects platform engineering, applied AI infrastructure, research tooling, and human-in-the-loop operational systems.Location: San Francisco, CA | 5 days/week in-office

About the Role Handshake is hiring a Senior Backend Software Engineer in San Francisco, CA. This role focuses on developing and improving the backend platform that powers the Handshake product. Work centers on building scalable systems that support user needs and enable new features.

Join Handshake as a Senior Cloud Engineer, where you'll play a pivotal role in designing and implementing scalable cloud solutions. Your expertise will help us enhance our cloud infrastructure while ensuring high availability and security.We are looking for a passionate and driven individual who thrives in a fast-paced environment, is eager to tackle complex challenges, and enjoys collaborating with cross-functional teams. If you have a deep understanding of cloud architectures and services, we want to hear from you!

Join Handshake as a Software Engineer II!At Handshake, we are creating the career network tailored for the AI economy. Trusted by 20 million knowledge workers, 1,600 educational institutions, and 1 million employers including 100% of the Fortune 50, we facilitate career discovery and hiring, from freelance AI projects to internships and full-time roles. Our innovative approach has led to extraordinary growth, with projections to triple our Annual Recurring Revenue (ARR) by 2025.Why Handshake?Influence the evolution of careers in the AI economy on a global scale.Collaborate with elite AI labs, Fortune 500 companies, and renowned educational institutions.Join a leadership team with experience from Scale AI, Meta, xAI, Notion, Coinbase, and Palantir.Contribute to a rapidly expanding company generating billions in revenue.Role OverviewAs a Software Engineer II, you will take ownership of significant components of our core product, creating systems that enable millions to explore opportunities, connect with employers, and advance their careers. This role is ideal for those ready to elevate their skills beyond the fundamentals: driving features from concept to completion, engaging in technical design, and setting high standards for engineering excellence.You will collaborate closely with product managers, designers, and senior engineers to deliver full-stack experiences that are reliable, scalable, and user-centric. This is a position for those who seek real ownership and impactful contributions.Location: San Francisco, CA | In-office, 5 days a weekLead feature development across frontend and backend, from design to deployment.Develop scalable full-stack systems that enhance user experiences in search, discovery, matching, and onboarding.Implement backend APIs and workflows while maintaining high standards for reliability and performance.Engage in architectural discussions to establish best practices for the team.Write clean, maintainable code and actively participate in peer code reviews.Work collaboratively with product and design teams to transform ambiguous requirements into exceptional user experiences.Proactively identify and resolve technical debt and performance issues.

About HandshakeHandshake is the premier career network tailored for the AI-driven economy. With a robust platform connecting 20 million knowledge workers, 1,600 educational institutions, and 1 million employers—including every single Fortune 50 company—Handshake is at the forefront of career discovery, hiring, and upskilling. Our platform supports everything from freelance AI training roles to internships and full-time positions. This unique value proposition has fueled our remarkable growth, with expectations to triple our annual recurring revenue (ARR) by 2025.Why You Should Join Handshake Now:Play a pivotal role in shaping the future of careers within the AI economy, making an impact that resonates with your community.Collaborate with elite AI labs, Fortune 500 partners, and esteemed educational institutions.Join a talented team with leadership drawn from industry giants such as Scale AI, Meta, xAI, Notion, Coinbase, and Palantir.Help build a rapidly growing business projected to generate billions in revenue.About the RoleAs a Software Engineer at Handshake, you will be instrumental in developing products and systems that drive our core user experiences—from search and discovery to onboarding and beyond. You will work across the entire tech stack, delivering features that significantly enhance how millions of users discover opportunities, connect with employers, and embark on their career journeys.Your role will involve close collaboration with product managers, designers, and fellow engineers to create seamless, end-to-end experiences in a dynamic, mission-driven environment. Whether you're engineering AI-enhanced features, scaling backend systems, or developing user-friendly frontends, your contributions will have a tangible impact on our user base at scale.Location: San Francisco, CA | In-office 5 days a weekDesign and implement scalable full-stack systems that support essential user journeys, including search, discovery, matching, and onboarding.Develop and refine product features across both frontend and backend, ensuring a balance between speed and code quality.Construct backend APIs, asynchronous workflows, and frontend experiences that are reliable, scalable, and user-centric.Work closely with product managers and designers to transform requirements into polished, comprehensive user experiences.Write clean, maintainable code while actively participating in code reviews and upholding engineering best practices.Identify and troubleshoot issues related to system reliability, user flows, and performance.

Handshake seeks an Associate Software Engineer to join the team in San Francisco, CA. This position is designed for recent graduates and those at the start of their software engineering careers. The role provides a chance to work with experienced engineers and contribute to new software products. What you will do Collaborate with team members to develop and enhance software features Take part in code reviews and group discussions Build practical skills through hands-on engineering projects Who this role is for Recent graduates or early-career software engineers Those eager to learn and grow within a supportive team This is an on-site position based in San Francisco, CA.

About HandshakeHandshake stands at the forefront of the evolving AI economy, serving as a vital career network that connects over 20 million knowledge workers, 1,600 educational institutions, and 1 million employers, including all Fortune 50 companies. Our platform is trusted for career discovery, hiring, and skills development, facilitating everything from freelance AI training gigs to internships and full-time careers. Our unique value proposition has resulted in exceptional growth, with our annual recurring revenue tripling in 2025.Why you should join Handshake now:Play a pivotal role in shaping the careers of individuals in the AI economy, impacting your community and peers.Collaborate closely with leading AI labs, Fortune 500 partners, and top-tier educational institutions.Be part of a team guided by experts from renowned companies such as Scale AI, Meta, xAI, Notion, Coinbase, and Palantir.Contribute to building a rapidly expanding business with substantial revenue potential.About the RoleAs an AI Research Intern at Handshake during the summer of 2026, you will be integral to our research team, which specializes in developing data engines that drive the next generation of large language models. This internship will offer you the opportunity to engage in focused projects that could lead to publishable research contributions and immediate application within our production stack. The internship is set to commence between May and June 2026.Projects You Could TackleLLM Post-Training: Explore innovative RLHF/GRPO pipelines, enhance instruction-following capabilities, and refine reasoning-trace supervision.LLM Evaluation: Develop new multilingual and domain-specific benchmarks, conduct studies comparing automatic and human preferences, and perform robustness diagnostics.Data Efficiency: Implement active-learning loops, assess data value, generate synthetic data, and devise low-resource fine-tuning strategies.Each intern will own a defined research project, receiving mentorship from a senior scientist, with the goal of producing a manuscript suitable for archival or submission to a top-tier conference.

Handshake connects 20 million knowledge workers, 1,600 educational institutions, and 1 million employers, including all Fortune 50 companies, through its career network built for the AI economy. The platform supports career discovery, hiring, and upskilling, ranging from freelance AI training roles to internships and full-time jobs. Handshake’s growth is driven by its mission to enhance opportunities in the evolving job market, with a goal to triple annual recurring revenue by 2025. Shape the future of careers in the AI economy and see your work impact people around you. Work alongside leading AI labs, Fortune 500 partners, and top educational institutions. Join a leadership team with experience from Scale AI, Meta, xAI, Notion, Coinbase, and Palantir. Contribute to a business on track to generate billions in revenue. Role overview This Software Engineer I (Coding) position sits within Handshake’s Coding Pod in San Francisco. The team builds and maintains the data infrastructure and pipelines that power advanced AI coding models. The work spans applied machine learning, data engineering, and product development, with a focus on creating large, high-quality benchmark datasets to evaluate model performance on real-world coding tasks. What you will do Manage end-to-end data pipelines, including task generation, dataset assembly, quality checks, and delivery. Influence training and evaluation processes for next-generation coding models. Work with human-in-the-loop evaluation systems, coding tools, and automated assessment frameworks to maintain dataset quality and model effectiveness. Who thrives here This role suits engineers who enjoy backend systems, data pipelines, and developer tools, and want to help shape the future of AI-driven software development. Location San Francisco, CA (5 days per week in-office)

Handshake seeks a Senior Software Engineer based in San Francisco, CA. This position centers on designing and building software that enhances user experience while supporting the company’s business objectives. Role overview Collaboration is key in this role. The Senior Software Engineer will work with colleagues from different teams to deliver dependable applications. The work directly contributes to advancing Handshake’s mission of creating a more open and secure internet. What you will do Design and develop software with a focus on user experience Build reliable applications that align with business needs Partner with cross-functional teams throughout the development process

About HandshakeHandshake is revolutionizing the career landscape for the AI economy. Trusted by 20 million knowledge workers, 1,600 educational institutions, and 1 million employers—including all Fortune 50 companies—Handshake empowers career discovery, hiring, and professional development. From freelance AI training opportunities to internships and full-time roles, our platform is at the forefront of a rapidly evolving job market. We anticipate tripling our annual recurring revenue by 2025, showcasing our remarkable growth trajectory.Why you should consider joining Handshake:Play a pivotal role in shaping careers in the AI economy, influencing your community and beyond.Collaborate with leading AI labs, Fortune 500 partners, and prestigious educational institutions.Join a talented team featuring leaders from Scale AI, Meta, xAI, Notion, Coinbase, and Palantir.Contribute to a rapidly growing company generating billions in revenue.About the RoleAs a Software Engineer, you will play an essential role in developing systems that enhance user acquisition, onboarding, identity verification, and fraud prevention. Collaborating with experienced engineers and multidisciplinary teams, you will deliver high-quality, scalable software solutions. This position is perfect for an individual with a solid understanding of software engineering principles and a passion for impactful work.Your Responsibilities:Design and implement platform systems that facilitate user acquisition, onboarding, and identity infrastructure.Develop and maintain fraud prevention systems to uphold our platform's integrity.Write clean, high-quality code and implement thorough testing strategies to ensure product reliability.Collaborate with product managers, designers, and senior engineers to deliver seamless user experiences from initial engagement to activation.Engage in code reviews and leverage mentorship from experienced engineers to enhance your technical skills.

About HandshakeHandshake is revolutionizing the career landscape within the AI economy, connecting 20 million knowledge workers to 1,600 educational institutions and 1 million employers, including all Fortune 50 companies. Our platform empowers individuals to navigate their career journey, from freelance opportunities to internships and full-time positions. This unique proposition is driving our exceptional growth; by 2025, we aim to triple our Annual Recurring Revenue at scale.Why Join Handshake Now?Influence the future of careers in the AI economy on a global scale, impacting the lives of countless individuals.Collaborate closely with leading AI labs, Fortune 500 companies, and top-tier educational institutions.Be part of a dynamic team with leadership drawn from renowned companies like Scale AI, Meta, xAI, Notion, Coinbase, and Palantir.Contribute to the development of a rapidly growing business with substantial revenue potential.About the RoleAs a Software Engineer in the Consumer Experience team, you will be at the forefront of crafting essential experiences that enable students to discover opportunities, encompassing search functionalities, discovery pathways, job listings, and job searching capabilities.Your Responsibilities Include:Design and implement scalable systems that enhance search and discovery experiences across our platform.Develop innovative AI-driven experiences for students, including a conversational AI agent for resume assistance, job searching, and interview preparation.Utilize OpenAI real-time APIs and agentic frameworks to deliver intelligent, conversational features.Collaborate with cross-functional teams to integrate new features that enhance member value and engagement.Participate in code reviews to uphold high standards of code quality and mentor fellow team members to promote continuous learning.