Senior Backend Software Engineer

Location: San Francisco, CAType: Full-time, on-siteOverview: As the demand for AI agents surges, we are on a rapid hiring spree to meet this challenge. At AgentMail, we are innovating in a space where the solutions are still being discovered; we focus on creating systems that empower agents as essential components of the internet. If you thrive in building products from the ground up, we want to hear from you.AgentMail is developing an API that provides dedicated inboxes for AI agents, serving as their primary identity and communication hub. This isn't just AI-enhanced email; it's email tailored for AI.We are searching for a foundational engineer with robust backend and infrastructure skills to create the essential tools that agents will utilize for communication, authentication, and real-world operations. This role is perfect for someone who enjoys working with systems: APIs, distributed architecture, reliability, and developer tools.Why Join Us?Exceptional Team: Our team comprises industry experts with backgrounds in quantitative analysis, software engineering, and private equity, featuring talent from companies like Optiver, NVIDIA, Amazon, Modern Treasury, and KKR.Rapid Growth: Our user base has doubled every two weeks since January, and we anticipate this growth to continue. With agents soon surpassing human numbers, we expect significant market changes.Unique Position: We are the exclusive identity provider for AI agents, similar to how Gmail serves human users.Key ResponsibilitiesLead and mentor a team of 4-6 engineers.Design user-friendly APIs and abstractions for humans and AI agents alike.Develop high-performance, low-latency systems with AI agents as the end-users.Engage directly with our core infrastructure, managing the processing of hundreds of thousands of emails daily.Innovate at the intersection of advanced AI capabilities and traditional email systems.Oversee projects from inception through to production deployment.Produce clean, maintainable code along with comprehensive technical documentation.Actively gather and respond to customer feedback to drive improvements and refinements.

About the RoleJoin our pioneering team at vooma as a Backend & Infrastructure Software Engineer, where you will play a critical role in shaping the technical infrastructure of a transformative company.If you are passionate about creating not only resilient systems but also the foundational architecture of a groundbreaking enterprise from the outset, this position is ideal for you.We are looking for someone who excels at crafting infrastructure that is elegant, dependable, and secure, even under high-demand scenarios. You thrive on the challenge of scaling systems that enable intelligent agents and take pride in establishing reliable foundations that others can rely on.Your Key Responsibilities Include:Design and maintain secure, scalable infrastructure tailored for AI-powered agents in production environments.Deploy and optimize AI-driven services to meet high availability and performance standards.Manage infrastructure as code, alongside cloud environments and CI/CD pipelines.Implement monitoring, observability, and alerting systems to ensure the reliability of our infrastructure.Contribute to infrastructure security and adhere to best practices.You Should Have:Experience in deploying and productionizing machine learning or AI-centric workloads.Proficiency in developing secure, scalable infrastructures on platforms such as AWS, Azure, or GCP.In-depth knowledge of backend systems, networking, and container orchestration technologies (e.g., Kubernetes).Understanding of infrastructure security principles and compliance standards (e.g., SOC2).A proactive and hands-on mindset, with a strong drive to solve challenges from start to finish.

Join Kira Learning as a Senior Software Engineer, where you will play a pivotal role in shaping the future of educational technology. Our mission is to leverage cutting-edge AI technologies to make high-quality teaching and learning accessible to all.In this role, you will take ownership of essential backend systems and infrastructure that drive key product workflows. This position is perfect for engineers who thrive on developing reliable and scalable services while enhancing infrastructure and developer tools. Although the primary focus is on backend development, the ideal candidate should also be comfortable working across the stack, collaborating closely with product teams to deliver comprehensive features.Kira is a rapidly growing startup, supported by top-tier Venture Capital firms, including New Enterprise Associates (NEA) and Andrew Ng’s AI Fund.This is a full-time position that requires flexibility with work hours and availability outside of standard business hours. We have offices located in San Francisco, CA, and New York City, NY, and we expect employees to work in-person at one of these locations four days a week.

About SesameAt Sesame, we envision a world where computers can interact with us in authentic, lifelike ways—seeing, hearing, and collaborating as humans do. Our mission is to create an innovative computer interface that seamlessly integrates voice agents into everyday life. Our diverse team comprises founders from Oculus and Ubiquity6 and seasoned professionals from Meta, Google, and Apple, each bringing extensive expertise in hardware and software. Join us in pioneering a future where technology feels alive.About the RoleAs a Backend Infrastructure Engineer at Sesame, you will play a pivotal role in shaping the foundational aspects of our technology stack. This position focuses on developing high-impact infrastructure, services, and tools that are broad-reaching rather than narrowly defined. You will tackle scalability and architectural challenges across various domains, including agentic workflows, speech recognition and synthesis, IoT, large-scale training, and efficient low-latency inference. If you're driven by the challenge of creating an ultra-efficient, scalable, and reliable engineering ecosystem through a blend of tooling, services, libraries, and infrastructure, this is the perfect opportunity for you.Responsibilities:Design and develop foundational infrastructure to support serving, training, and applications at Sesame.Enhance productivity for engineering teams by automating processes and creating exceptional tools.Deliver software solutions that empower product and machine learning engineers to build secure, scalable, and dependable systems from the ground up.Your responsibilities will encompass provider, service, security, and developer infrastructure, as well as the architecture and implementation of core services and libraries.

About GigaGiga has recently secured $61 million in Series A funding and is already collaborating with prominent clients, including DoorDash. We are on a mission to revolutionize customer experience by developing advanced AI agents capable of understanding emotions, resolving issues instantaneously, and scaling solutions across the globe's largest enterprises.This pivotal moment in our journey reflects our ambition to establish ourselves as the leading AI platform for enterprise automation, driven by our cutting-edge voice superintelligence. To realize this vision, we are seeking exceptional engineers to join our team.Our work impacts millions of lives daily, providing engineers with the autonomy to make a genuine difference. This role offers a unique chance to be part of a talented founding team, achieve commercial success, and contribute to a company with the potential to become a generational leader.For more insights into Giga, check out:Voice AI startup Giga raises $61M Series ADoorDash and Giga PartnershipJoin us and help build AI agents that are trusted by the world’s leading B2C companies, including DoorDash, as they navigate complex support and operational workflows across voice, chat, and email channels.The RoleWe are in search of a skilled infrastructure engineer to develop the foundational platform that powers our AI agents. Your primary users will be fellow engineers; your mission will be to design systems, tools, and abstractions that enhance productivity and ensure the reliability of our platform.This position goes beyond traditional DevOps or SRE roles. You will be writing application code with a specific focus on foundational layers such as deployment systems, observability, data infrastructure, and the internal tools that enable swift, efficient operations without compromising stability.What You'll Work OnHere are a few key projects you will be involved with:Controlled deployments: Implementing staged rollout systems with traffic scaling, scheduling, and pass rate thresholds to protect production environments.Observability: Developing instrumentation, logging, and monitoring frameworks that provide insights into production performance.Data infrastructure: Creating robust data pipelines and storage solutions to support our operations.

Join Sphere, where we leverage AI technology to redefine international trade law.At Sphere, we empower companies like Lovable, Eleven Labs, Replit, and Runway AI to seamlessly automate their sales tax, VAT, and GST compliance:Experience rapid growth with us (30%+ month-over-month revenue increase) as we collaborate with some of the fastest-growing tech companies globally.After two years of dedicated effort, we have integrated local compliance solutions into over 100 tax authorities worldwide, a feat unmatched by any other vendor.We are developing the first AI-native tax engine, forming the backbone of a comprehensive cross-border compliance platform.Our funding partners include industry leaders such as a16z, Y Combinator, 20vc, and Felicis Ventures.As we scale to accommodate millions of global transactions, building a robust infrastructure for transaction synchronization and real-time tax calculations is crucial.This role focuses on ensuring availability, resilience, and speed within mission-critical billing flows for leading companies.Why This Role is a Major Opportunity: Enormous Total Addressable Market: Every business requires compliance solutions. Favorable Market Trends: As businesses expand globally, the urgency for compliance solutions increases. AI-Driven Advantages: Our AI-native tax engine allows us to scale beyond traditional limitations. Multi-Product Expansion: Indirect tax is just our starting point; we are building a comprehensive solution for all revenue-based compliance needs.Your Responsibilities:In the initial weeks:Identify innovative solutions to enhance Sphere's infrastructure...

Biotechnology is transforming our world, influencing everything from the medicines we consume to the crops we cultivate and the materials we utilize daily. To keep pace with the rapid advancements in science, we require cutting-edge technology.At Benchling, our mission is to harness the potential of biotechnology. The most pioneering biotech firms rely on Benchling’s R&D Cloud to facilitate the creation of innovative products and accelerate their journey to milestones and market readiness.Join us in bringing state-of-the-art software solutions to the forefront of modern science.ROLE OVERVIEWWe are seeking a talented Backend Software Engineer to join our Infrastructure Engineering team, where you will build and maintain the foundational platform that powers our product offerings. This role spans various infrastructure disciplines, including cloud infrastructure on AWS, services based on Kubernetes, and the operational tools necessary to ensure system reliability. Collaboration is key as you will work closely with product engineering teams to better understand their requirements and enhance the developer experience throughout Benchling.We are looking for a motivated early-career engineer with strong foundational skills and a desire to grow. The ideal candidate will be enthusiastic about learning, eager to contribute across diverse areas, and ready to take on increasing responsibilities. Given our operation in a regulated environment, your work will focus on building reliable, secure, and auditable systems.RESPONSIBILITIESDevelop, sustain, and enhance core infrastructure and platform services utilized by our product engineering teams.Collaborate with product teams to establish requirements, design efficient pathways, and minimize deployment and operational challenges.Contribute to our Kubernetes-based platform, including service configuration, traffic management, and platform tooling.Design and manage AWS infrastructure and automation, emphasizing scalability, cost efficiency, and resilience.Enhance observability and operational readiness through metrics, logging, tracing, dashboards, and alert systems.Engage in an on-call rotation, manage incident responses, and drive process improvements to avert future occurrences.Produce clear technical documentation and engage in design discussions and reviews; focus on incremental system improvements for maintainability and reliability.

ABOUT US:Skip is dedicated to enhancing joy through advanced movement solutions.Our mission is to empower individuals by restoring mobility, as movement is essential for physical, mental, and social well-being. Yet, over 2 billion people face mobility challenges due to age, injury, or disability. We are committed to creating innovative products that will enable joyful movement experiences for everyone, ensuring that no one is left behind.Founded in 2023 as a spin-off from Google X, Skip is a dynamic 22-person startup positioned to revolutionize the market with our flagship wearable robotic device, the MO/GO. Through strategic partnerships, such as with Arc’teryx, we are set to launch a new era of Movewear products that will transform lives globally.THE ROLE:We are seeking a proactive Senior Backend Engineer to navigate the challenges of developing cutting-edge wearable robotics for everyday use. As a vital member of our software team, you will take charge of backend development and cloud infrastructure, contributing to the establishment of a groundbreaking consumer robotics platform.In this flat organizational structure, you will also play a crucial role in mentoring junior team members as we scale our operations.Key responsibilities include:Develop and oversee backend systems with an emphasis on containerized services and cloud storage solutions to support the deployment of 5,000 MO/GOs over the next two years.Automate infrastructure management using tools such as Terraform, enhancing deployment efficiency and scalability.Facilitate safe and sustainable scaling, transitioning from a single cloud project to separate Development and Production environments in GCP, while maintaining system safety and data integrity.Design and refine data storage and retrieval processes, optimizing storage solutions and data ingestion pipelines to accommodate increasing data demands.Streamline CI/CD workflows currently hosted on GitHub, optimizing cost-efficiency through improved test run segmentation and potential hosting on GCP virtual machines.

About LangChainLangChain is dedicated to revolutionizing the landscape of intelligent agents. Our innovative agent engineering platform and open-source frameworks empower developers to efficiently create reliable agents with speed and precision.With over 90 million downloads monthly, our frameworks, LangChain and LangGraph, are instrumental for developers looking to build sophisticated agents. LangSmith enhances this experience by providing observability, evaluation, and deployment capabilities that facilitate rapid iteration, ensuring teams can seamlessly transition LLM systems into dependable production environments.Trusted by millions globally, LangChain supports AI teams at leading organizations such as Replit, Clay, Cloudflare, Harvey, Rippling, Vanta, Workday, and many others.About the RoleThis position requires in-person attendance five days a week in either San Francisco, CA or New York, NY. We are developing specialized infrastructure tailored for the execution of AI agents. Unlike conventional web applications, these agents operate for extended periods, engage asynchronously with both humans and other agents, and must be resilient to failures during execution. The LangSmith Deployments runtime is designed to support these functionalities through durable checkpointing, fault-tolerant orchestration, and horizontal scaling across both cloud and self-hosted environments.We are seeking a Senior Backend Engineer to contribute to this vital system. While the primary focus will be on backend development, a strong understanding of Kubernetes (K8s), Terraform (Tf), and other DevOps tools is highly desirable.Design and implement distributed queue and worker systems to manage concurrent agent execution, background tasks, and multi-agent coordination within horizontally scalable infrastructure.Take ownership of core data infrastructure, including state persistence, atomic job claiming, connection management, and schema evolution.Collaborate on architectural decisions to ensure scalability and robustness of solutions.Develop resumable streaming infrastructure, allowing clients to disconnect and reconnect during execution without loss of state.Monitor and instrument production systems, including tracing, metrics, and alerting to maintain platform health.Participate in on-call rotations and manage incident response for the runtime.Create and maintain technical documentation, encompassing system design and operational runbooks.Contribute to and enhance the open-source LangGraph, utilized by thousands of developers to create agent applications.

About UsWe are an innovative stealth-mode company funded by a16z Speedrun, dedicated to empowering leading consumer brands to achieve exceptional growth. Our cutting-edge solutions have gained the trust of pioneering organizations like Higgsfield and Promova among others. As we expand, we seek talented individuals who are eager to make a significant impact in the realm of consumer technology. You will be part of a passionate team at a crucial juncture, thriving in an environment that champions initiative, ambition, and creative solutions.The RoleAs a Senior Backend Engineer, you will be instrumental in developing and maintaining the essential backend infrastructure that powers our products. Your responsibilities will include:Designing scalable architectures that effectively support new product features and business objectives.Leading the development, deployment, and optimization of backend services to ensure top performance, reliability, and maintainability.Collaborating with cross-functional teams to seamlessly integrate third-party platforms, APIs, and cutting-edge AI technologies.Facilitating technical discussions, providing mentorship, and sharing best practices with fellow team members.Actively contributing to the continuous enhancement of our engineering standards and development workflows.Proactively identifying and addressing complex technical challenges to ensure stable and secure operations.What We ExpectA minimum of 5 years of professional experience in backend development, showcasing a history of delivering reliable and scalable systems.Advanced expertise in server-side programming and experience in designing database-driven applications.A solid understanding of API development, systems integration, and software engineering best practices.Proven experience in building and maintaining production environments that scale effectively for real users.An independent, proactive approach to problem-solving, coupled with the ability to drive projects forward.A commitment to joining our team full-time, with a desire to grow within a fast-paced, ambitious startup.How to ApplyPlease send us a brief introduction about yourself, along with a description of a technical project or system you are most proud of. We are excited to learn how you can contribute to our vision and success.

About the PositionAs a Senior Backend Engineer at Nash, you will be instrumental in the design and development of our backend systems, services, and APIs. Collaborating closely with our CTO, co-founder, and the engineering and product teams, you will help scale our platform, enhance performance, and build a robust infrastructure that facilitates seamless logistics operations. This role presents an exciting opportunity to contribute to Nash as we create innovative products across the logistics value chain for enterprises, marketplaces, and small to medium-sized businesses (SMBs).Key ResponsibilitiesDesign, develop, and maintain high-performance, scalable backend services and APIs.Architect and implement efficient data structures and models.Optimize system performance, scalability, and security.Debug, troubleshoot, and resolve backend issues in production environments.Work closely with frontend engineers to develop seamless API integrations.Implement best practices for observability, monitoring, and logging to ensure system reliability.Collaborate both independently and as part of a team to tackle complex technical challenges.Promote best practices in documentation, testing, and maintainability.Qualifications4+ years of experience in developing and deploying scalable backend systems.Proficient in Python and related backend frameworks.Experience in designing and utilizing RESTful APIs and databases (e.g., PostgreSQL, AWS RDS).Solid understanding of cloud platforms (preferably AWS) and deployment best practices, including managed services (serverless, databases, queues) and CI/CD pipelines.In-depth knowledge of scalable system design and performance optimization.Exceptional problem-solving skills with the ability to work independently in a dynamic environment.Startup experience is advantageous but not mandatory.Preference for candidates located in the Bay Area; Nash operates a hybrid-first product team with an office in San Francisco.Bonus: Familiarity with AsyncIO and event-driven programming.

About Atomic SemiAtomic Semi is pioneering the development of a compact and rapid semiconductor fabrication facility.Utilizing current technologies and innovative simplifications, we aim to create our own tools, enabling swift iterations and continuous enhancements.Our team comprises exceptional, hands-on engineers across various disciplines—mechanical, electrical, hardware, computer, and process engineering. We are committed to owning our entire operational stack, from atomic structures to architectural designs. Our optimistic outlook drives us to push the boundaries of technology.We believe that smaller, faster solutions are superior, and that building our own tools is the best path forward.Equipped with advanced 3D printers, an extensive range of microscopes, e-beam writers, and general fabrication tools, we are ready to invent whatever is necessary throughout this journey.Founded by Sam Zeloof and Jim Keller, our vision is backed by Sam’s garage-chip manufacturing experience and Jim’s four decades of leadership in the semiconductor industry.About the RoleAs a Backend Infrastructure Engineer, you will develop the core systems that drive our fabrication products, with a focus on backend architecture, data models, and hardware integrations.

tvScientific, now part of Pinterest, develops a connected TV advertising platform designed for performance marketers. The team brings together expertise in data, automation, and digital media to help brands buy, optimize, and measure TV ads more effectively. The platform integrates media buying, optimization, measurement, and attribution, aiming to offer advertisers a dependable way to grow through CTV. Role overview The Senior Backend Engineer will design, build, and scale systems that manage contracts and billing for direct advertisers, internal teams, and the Finance department. This work centers on backend services that support a range of contract types and billing models, with a focus on accuracy, auditability, and operational reliability. What you will do Architect and develop backend services for contracts and billing Support multiple contract structures and billing models Ensure system correctness and auditability Maintain operational reliability as the platform expands Work on systems that manage complex commercial relationships and external partners Keep contract logic consistent, adaptable, and maintainable Where this role fits This senior backend engineering role connects revenue, finance, and customer operations. Success in this position requires clear domain modeling, strong data integrity, and disciplined engineering practices. Location Based in San Francisco, CA, or remote within the United States.

Join Mercury as a Senior Infrastructure Engineer, where you will be pivotal in shaping the infrastructure that supports our innovative financial solutions. You will work closely with cross-functional teams to design, implement, and maintain scalable and reliable infrastructure systems. This role is ideal for individuals who thrive in a fast-paced environment and are passionate about leveraging technology to drive business success.

Rockstar is on the hunt for a talented Backend Software Engineer to join a rapidly expanding startup that is pioneering the AI infrastructure for the next generation of smart products. This innovative company specializes in providing AI startups with the tools to design, fine-tune, evaluate, deploy, and maintain their specialized models across various domains like text, vision, and embeddings. Think of them as the 'AWS for AI models'—offering a comprehensive backend solution for fine-tuning, reinforcement learning, inference, and ongoing model maintenance. Their clientele includes Series A to C AI companies that are developing enterprise-grade products, with a simple promise: to enhance your AI systems.As a Backend Software Engineer focusing on ML Infrastructure, you will play a pivotal role in designing, building, and scaling the essential systems that facilitate extensive model training and deployment.Your responsibilities will include developing distributed training pipelines, establishing cloud-native infrastructure, and creating internal developer platforms that support fine-tuning, reinforcement learning, and inference at scale. This position uniquely combines backend engineering with machine learning systems, allowing you to work closely with ML engineers while taking ownership of production-grade infrastructure.This role is a fantastic opportunity for an early-career engineer eager to dive into real distributed systems, GPU workloads, and cutting-edge ML infrastructure—far removed from simple dashboards or CRUD applications.

Join our dynamic team at Bland Inc. as a Senior Infrastructure Engineer, where you will play a critical role in designing and implementing robust infrastructure solutions. You will work alongside a talented group of professionals, using cutting-edge technology to drive innovation and efficiency.

Join Fieldguide as a Senior Infrastructure Engineer and be at the forefront of our innovative infrastructure solutions. In this role, you will lead the design, implementation, and maintenance of our infrastructure systems while ensuring optimal performance, security, and scalability. Your expertise will help shape our technology strategy and drive impactful projects.

Be part of our mission to redefine AI by shaping the narrative surrounding document understanding.Role OverviewAt LlamaIndex, our Infrastructure team lays the groundwork for our product and provides essential tools that facilitate the development, deployment, and monitoring of our code. We are tasked with designing, constructing, and scaling the core infrastructure that drives a high-capacity data platform for AI applications. We seek individuals who are passionate about creating supportive systems that enhance our engineering capabilities and contribute to our rapidly expanding product suite.Ideal candidates will have a strong background in cloud infrastructure management, navigating various scalability challenges, and enhancing the productivity of the broader Engineering team. Key traits we value in our culture include a customer-centric mindset, collaboration, diligence, and optimism. We are looking for proactive team players who are eager to help us evolve our culture as we grow.Key ResponsibilitiesCollaborate with engineering teams to develop and maintain foundational systems that empower developers and support our rapid growth.Design and execute scalable infrastructure solutions suitable for various deployment models, including SaaS, single-tenant, and private environments.Oversee and optimize cloud resources and Kubernetes clusters to ensure cost-effectiveness and high performance.Facilitate successful external customer deployments by establishing clear infrastructure guidelines and principles.Enhance the release and deployment processes to improve efficiency and reliability.Ensure compliance with applicable regulations and implement comprehensive security measures across all deployment environments.QualificationsMinimum of 5 years of engineering experience.Experience working on Platform or Infrastructure teams on substantial projects involving infrastructure components like Terraform/CDKTF, Kubernetes, Helm, testing infrastructure, release management, and observability.Proficient in optimizing cloud resource utilization.Skilled in tuning Kubernetes clusters and cloud resources for optimal performance and cost efficiency.Dedicated to cultivating LlamaIndex’s engineering culture as we expand.Ability to balance speed and pragmatism in delivering solutions.

Are you a passionate engineer with a knack for building robust infrastructure? Join our dynamic team at fal as a Senior/Staff Infrastructure Engineer. In this pivotal role, you will design and implement innovative solutions that enhance our infrastructure's efficiency and reliability.As a key member of our engineering team, your responsibilities will include:Architecting scalable infrastructure solutions to meet our growing needs.Collaborating with cross-functional teams to identify and resolve infrastructure challenges.Implementing automation tools and frameworks to streamline operations.Monitoring performance and ensuring the security of our systems.Providing mentorship and guidance to junior engineers.We are looking for individuals who thrive in a fast-paced environment and have a deep understanding of infrastructure technologies.