Senior Backend Engineer at Langfuse | Europe

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 log…

Join our innovative team at natter as a Senior Backend Engineer! We are looking for a passionate engineer to help us build scalable backend systems and contribute to our growing projects. If you thrive in a collaborative and remote environment, we want to hear from you!

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 SolaceAt Solace, we're on a mission to revolutionize healthcare in the U.S. The healthcare system is fraught with complexity, leaving 88% of adults lacking the health literacy to navigate it independently. Our innovative approach connects patients with expert advocates and equips them with essential tools for informed decision-making, ultimately leading to better health outcomes.Founded in 2022 and backed by prominent investors like Inspired Capital and Menlo Ventures, we are a rapidly growing Series C startup. Our dedicated, mission-driven team is based in the U.S. and is committed to making a genuine impact in the healthcare landscape.Solace is not a place for complacency; we strive for urgency, precision, and compassion. If you're eager to challenge yourself, enhance your skills, and contribute to meaningful work alongside a passionate team, you've found your ideal environment. We thrive on intensity and are driven to excel.About the RoleAs a Senior Backend Engineer, you'll be an integral part of our talented engineering team. You'll take full ownership of your product workflow, from conceptual design to deployment. We expect you to work dynamically, committing code daily while witnessing the immediate impact of your contributions in real-time as we build groundbreaking solutions from the ground up.Your expertise will be crucial in identifying issues and architecting high-quality solutions. You should be curious, enjoy tackling ambiguous challenges, and take pride in your work. Strong communication skills and the ability to absorb feedback are essential. Embrace the learning journey from mistakes, and thrive in a fast-paced environment free from the constraints of large organizations.What You'll DoDesign and implement scalable services and APIs that enhance both existing and new features of our web applications.Architect and maintain resilient backend systems while managing database models for optimal performance.Collaborate closely with cross-functional teams to ensure seamless integration and functionality of systems.Continuously optimize and refine backend processes to enhance efficiency and user experience.Contribute to code reviews and foster a culture of excellence and innovation within the engineering team.

Join our dynamic team as a Senior Backend Engineer at antithesis, where you will play a crucial role in developing innovative backend solutions that drive our cutting-edge projects. As a Senior Backend Engineer, you will work closely with cross-functional teams to design, implement, and optimize our backend architecture, ensuring high performance and scalability.

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.

About the RoleAs a Senior Backend Engineer at sportygroup, you will play a pivotal role in crafting robust microservices within a distributed deployment framework. Emphasizing containerization with Docker and Kubernetes, your work will go beyond basic CRUD applications, immersing you in the core logic of complex systems that handle millions of daily requests. Our platform, developed from the ground up three years ago, leverages the latest technologies, freeing you from the burdens of legacy code. If you are eager to work with Spring Boot and possess solid experience in an object-oriented programming language, we welcome your ambition to learn.Our Technology Stack (Familiarity with all is not required)Languages: Java 17Frameworks: Spring Boot (Tomcat, Netty), Spring Data, Spring CloudArchitecture: Microservices, REST APIs, Message QueuesDatabases: MySQL, MyBatis, ShardingSphere, MongoDBCaching: Redis (AWS ElastiCache), ElasticSearchMessage Queues: RocketMQCloud: Docker, Kubernetes, AWSMonitoring: Grafana, Prometheus, Loki, Tempo, AWS CloudWatchYour ResponsibilitiesDevelop scalable backends for mobile applications serving millions of users.Collaborate with Product Owners and development teams to define necessary features and user stories for new and revised applications or complex projects.Engage in peer and manager code reviews to ensure adherence to original visions and appropriate architecture patterns.Respond to production support inquiries for prompt diagnosis and resolution to maintain seamless user experiences.Participate actively in team ceremonies, including planning, grooming, product demonstrations, and retrospectives.Mentor junior team members and share knowledge.Potential on-call responsibilities based on team and tenure.Your BackgroundA minimum of 6 years of experience in a relevant role.Preferred experience with Spring Boot, Spring Cloud, Spring Data, and iBATIS.Proven track record in developing highly scalable web backends.Experience in designing high-transaction systems.Strong proficiency in Object-Oriented Design (OOD) and analysis.Advanced understanding of application analysis and design engineering functions.Expertise in applying non-functional software qualities such as resiliency and maintainability.

Location: Austin (Domain), TX (In-office 4x per week) Company: Kizen, www.kizen.com OTE - $207,000-$253,000 About Us Kizen is pioneering the future of work with our innovative platform, AI Agents, and True Context Technology (TCT), serving leading organizations in highly regulated sectors such as insurance, healthcare, and financial services. Our platform empowers organizations to streamline their most critical workflows — from assisting insurance agents with contracting and commissions, to enabling healthcare providers to offer proactive patient care, and empowering financial institutions to automate document classification and data extraction. At Kizen, we enable developers to craft new enterprise applications and impactful AI agents, while allowing business users to tailor dashboards and agents using natural language, low-code, or traditional coding — all within a unified platform. What once took months or years to develop can now be accomplished in mere days. Kizen merges cutting-edge pre-built agents and use cases with an enterprise platform designed for automation and data connectivity, all built on an AI-first architecture that is user-friendly, scalable, and reliable. We are committed to solving genuine operational challenges and assisting the world’s most complex organizations in working faster, smarter, and more empathetically. Join us in redefining industry workflows — one process, one agent, and one success story at a time. About the Role Are you ready to shape the future of work? We’re translating AI and intelligent automation into practical applications for real users. We are seeking a proactive Senior Engineer with a track record of prioritizing user outcomes and swiftly delivering dependable, scalable systems as we launch our next-gen platform. This is an exceptional opportunity for anyone eager to be at the forefront of the AI revolution that enhances human existence. As a Senior Backend Engineer, you will collaborate closely with our Director of Platform Engineering to develop new user-facing features and enhancements while scaling the Kizen platform to meet our users’ evolving requirements. Our core values form the essence of Kizen’s identity. They are ingrained in our culture, guide our decisions, and reflect in our interactions with customers, partners, and each other.

Join Via, where we leverage technology to revolutionize global transportation. As a Senior Backend Engineer, you will play a pivotal role in our Platform team, contributing to innovative solutions that impact the daily commutes of thousands while minimizing environmental impact. Collaborate with a talented group of developers and DevOps engineers to build and maintain the cutting-edge infrastructure that powers our operations. This hybrid role requires you to be onsite in NYC 2-3 days a week, allowing for hands-on teamwork and collaboration.

Role overview As a Senior Backend Engineer at Postscript, the focus is on building and refining the core systems that power the platform. This role is fully remote, offering flexibility while working with a distributed team. The position emphasizes designing backend solutions that enable the platform to scale and remain reliable as it grows. What you will do Collaborate with teams throughout the company to design backend systems that can scale as demand increases Work to optimize performance and ensure the reliability of platform services Share ideas and develop solutions to strengthen the backend architecture

Join squaredomain as a Senior Backend Server Engineer and contribute to the development of innovative gaming solutions. We are on the lookout for a talented individual with expertise in backend technologies to enhance our e-commerce systems and web gaming experiences.Proficiency in Python; knowledge of Object-Oriented programming, especially in C++, would be a bonus.Experience with AWS and IaaS platforms.Familiarity with Linux environments and source code control systems, along with release management practices.Experience in building and consuming RESTful APIs.Experience with Django, Tornado, or Twisted is a plus.Knowledge of Node.js and frameworks like AMQP.Strong background in API development and integration.

Join dualentry as a Senior Backend Engineer, where you'll be at the forefront of developing cutting-edge backend solutions. In this role, you will collaborate with cross-functional teams to design, implement, and optimize robust server-side applications. Your expertise will be crucial in enhancing system performance, scalability, and security.

Senior Staff Backend EngineerLocation: Manhattan, New YorkOnsite | Full-timeJoin our dynamic team at mlabs, the innovative engine behind one of the most visited platforms in the digital asset industry. With a staggering ~$1B in daily volume, our cutting-edge technology stack is designed to manage low-latency, high-throughput, and consistent load at an unprecedented scale.The RoleAs a Senior Staff Backend Engineer, you will be a pivotal technical leader, ensuring the robustness and continuous advancement of our core backend systems. Your role involves a combination of high-level architectural oversight and hands-on execution, focusing on mitigating scaling challenges and designing resilient, fault-tolerant systems that can handle substantial workloads.What You’ll Do:Own & Execute: Take charge of writing and deploying production code for core services, leading the design and implementation of high-scale distributed systems.Architect for Scale: Make informed decisions that harmonize swift iteration with long-term system scalability and maintainability.Drive Initiatives: Spearhead projects that involve multiple services, including storage, compute, APIs, and blockchain infrastructure.Set the Standard: Create benchmarks for observability, reliability, and performance, while enhancing engineering quality through design reviews and RFCs.Technical Leadership: Serve as a technical anchor during critical incidents and mentor peers, sharing your depth of knowledge and clarity of thought.Optimize Velocity: Enhance the internal developer experience by refining tools, CI/CD pipelines, and service abstractions.

About AtticusEvery day, millions of Americans find themselves in urgent need of legal or governmental support due to crises affecting their lives. At Atticus, we believe that the right assistance can significantly change these individuals' futures, yet too many never receive it.Our mission is to simplify access to vital help for those who are sick or injured. Over the past six years, we have emerged as the premier platform connecting individuals with disabilities to essential government benefits, assisting hundreds of thousands in securing over $10 billion in aid, and garnering more than 17,000 five-star reviews.With over $100 million raised from notable investors such as Fika, Forerunner, GV, and True Ventures, and the successful closure of our Series C funding in April 2025, our financial future is solid. Our team has expanded from 151 to 210 members in 2025, and we are poised for further growth in 2026.The RoleAs part of the Growth Pod at Atticus, you will play a pivotal role in bridging our marketing, product, and data layers. We prioritize speed, iterative experimentation, and accountability. We are seeking a backend-focused product engineer who excels in dynamic environments and can efficiently manage experimentation without leaving behind complications.This position emphasizes the development of systems that enhance Growth: ensuring seamless data flow between systems, managing experimentation infrastructure, marketing data pipelines, automated communications, and user identity management. If you have experience in these areas and desire to delve deeper, this is your opportunity.Additionally, you will collaborate closely with product and design teams to transform vague Growth hypotheses into clear, actionable tasks that can be executed swiftly and rigorously tested.Your ResponsibilitiesManage and enhance our data integration infrastructure, including data systems, marketing tools, customer communication platforms, and experimentation data flows.Create connections between Growth's external tools and internal systems.Work collaboratively with the Growth team to convert rapidly evolving priorities into well-defined engineering tasks.Strive for a balance between speed and system integrity, making strategic trade-offs and documenting your decisions.Engage across our entire product stack as necessary; while the focus is on backend work, we appreciate a generalist engineering approach.

Join GitLab as a Senior Backend Engineer, focusing on the SSCS: Authorization team. In this role, you will develop and maintain robust backend systems that empower our clients' authorization processes. As part of a fully remote team, you will collaborate with cross-functional teams to deliver high-quality software solutions that meet the needs of our diverse customer base.Your expertise will be crucial in ensuring that our backend architecture is scalable, efficient, and secure. If you are passionate about backend development and want to make a significant impact in a dynamic environment, we would love to hear from you!

Senior Backend EngineerLocation: Remote (US)Type: Full-timeExperience: 5+ yearsAbout AstraAt Astra, we are a dynamic engineering team dedicated to crafting mission-critical financial infrastructure. Our innovative fintech platform efficiently manages payment processing, fraud detection, and financial compliance for enterprises handling over $100 million in transactions weekly. We pride ourselves on maintaining over 99.9% uptime, executing complex cross-border payments, and collaborating with various third-party financial services while adhering to stringent regulatory standards.The RoleWe are seeking a talented Senior Backend Engineer to design and develop sophisticated financial systems that process millions of dollars on a daily basis. In this pivotal role, you will be among our core engineers, creating cross-domain solutions that synchronize payments, fraud detection, compliance, and user management within our distributed microservices architecture.This position demands exceptional systems thinking, technical leadership, and the capability to tackle intricate engineering challenges that span multiple domains and external integrations.What You'll DoDesign and develop essential financial systems: Create and implement payment processing, fraud detection, and compliance systems that manage millions in daily transactions while adhering to strict regulatory requirements.Lead cross-domain solutions: Facilitate complex interactions among payments, fraud detection, user management, and compliance systems.Drive architectural decisions: Influence architecture decisions that affect the entire platform and set best practices for our growing team.Mentor junior engineers: Support the development of junior engineers by establishing coding standards, design patterns, and engineering practices.Enhance system performance: Improve the reliability and efficiency of our distributed microservices architecture.Collaborate with other teams: Work closely with product and compliance teams to create systems that address business and regulatory requirements.What We're Looking ForSenior Backend Engineer Requirements5+ years of software engineering experience in developing complex production systems.Proven expertise in systems engineering and resolving intricate, cross-domain challenges.

Join our dynamic Platform team at Zerion as a Senior Backend Engineer. In this pivotal role, you will shape and enhance the backend architecture that powers our products and customer solutions.Your responsibilities will include designing and managing distributed systems, engaging with Web3 infrastructure, and collaborating closely with product and platform engineers to create reliable and scalable solutions.We prize strong ownership, meticulous system design, and an unwavering commitment to code quality. If you thrive in building robust systems, moving swiftly without compromising on quality, and leveraging modern tools (including AI) to enhance efficiency, we would love to have you on our team.

Join our innovative team as a Senior Backend Engineer at Pindrop. In this pivotal role, you will leverage your expertise to design, develop, and maintain backend systems that enhance our cutting-edge technology solutions. Collaborate with cross-functional teams to deliver high-quality software that meets the demands of our clients.

About Us:At Stay AI, we are a team of experienced professionals from the Direct-to-Consumer (DTC) sector, having built subscription programs for over a decade. We have partnered with over 300 subscription-focused Consumer Packaged Goods (CPG) brands, collectively generating substantial revenue in subscriptions. Our product is crafted by passionate marketers who excel in acquisition and retention strategies.We proudly collaborate with esteemed investors such as Telescope Partners, Boulder Food Group, Riverpark Ventures, Vanterra Capital, and Watchfire Ventures, alongside industry pioneers like Nik Sharma (Sharma Brands) and Adam Turner (Postscript).Our mission is to establish the essential infrastructure that supports subscription services for contemporary commerce brands. This includes building robust, scalable systems that integrate deeply with Shopify, going beyond mere API consumption.If you are passionate about engineering critical infrastructure at the nexus of platform technology and commerce, we invite you to learn more.Our Culture:We take pride in our craft and celebrate our achievements. Collaboration is vital to our operations, as we believe that exceptional engineering stems from strong alignment between Engineering, Product, and Design teams.As a remote-first company, we prioritize genuine connections through annual retreats in locations like Park City and Mexico. We work swiftly, prioritize quality, and empower our engineers to take ownership of their outcomes.Your Role:In your role as a Senior Backend Engineer at Stay AI, you will design and develop the fundamental systems that enable our seamless operation within the Shopify ecosystem, serving numerous subscription brands and millions of subscribers. You will collaborate closely with cross-functional teams to implement our leading-edge features, including AI capabilities that keep Stay ahead of the competition. As a seasoned technical leader, you will set standards for our Shopify integrations and shape the future of subscription management.