Staff Backend Engineer, Recommender Systems

Join our innovative team at Raya as a Staff Backend Engineer specializing in Recommender Systems. In this fully remote role, you will leverage cutting-edge technology to develop and enhance our recommender systems, ensuring optimal user experience and engagement. Collaborate with cross-functional teams to design scalable solutions that drive business value.

Become a Part of the VRChat Revolution!VRChat is pioneering the social VR landscape with an innovative platform that offers a limitless array of immersive experiences. Empowering our vibrant community of creators, we currently host over 250,000 unique worlds and continue to expand. Our mission is to enable users to manifest their creativity and actively contribute to the metaverse from anywhere, on any device. Backed by $100M in funding from esteemed investors like Makers Fund, Anthos Capital, and HTC, we are excited about the future.Join our dynamic team, comprised of talented individuals from leading companies such as Netflix, Twitter, Meta, Microsoft, Roblox, Google, Amazon, Unity, Spotify, Discord, Uber, eBay, Robinhood, Twitch, Zynga, and TikTok. We invite you to be part of our mission!Position SummaryWe are in search of a skilled Data/ML Engineer to enhance our Social Experience team. In this pivotal role, you will design and optimize data-driven recommendation systems that facilitate user connections, interactions, and content discovery. Your work will involve utilizing AWS, Python/FastAPI, Node.js, and Snowflake to construct, train, and implement personalized systems. You will play a key role in processing and transforming the extensive data generated by our platform to create enriching user experiences. If you possess a passion for data engineering and are eager to leverage data to improve content discovery, this opportunity might be ideal for you.

At Assured, we're transforming the insurance landscape by modernizing claims processing—a crucial yet often neglected aspect of the industry. Currently fraught with inefficiencies such as phone calls and faxes, this sector costs billions annually. We believe there's a better way.Our mission is to equip large insurers with cutting-edge software solutions that thrive in today's technology-driven environment. From self-service claim-filing systems to sophisticated backend fraud detection, we are the driving force behind claims processing for some of the world's largest insurance providers.The challenges we tackle are varied and intricate, ranging from crafting digital experiences that offer comfort and clarity to claimants in distress, to orchestrating large-scale, machine learning-driven decision-making for billions in claims payments. Life at Assured is dynamic, collaborative, and fulfilling.We are seeking a seasoned Senior Backend Engineer to play a pivotal role in shaping the future of our rapidly expanding B2B SaaS platform. As an essential contributor to our engineering team, you will take ownership of critical systems from architecture and infrastructure to core business logic, ensuring our scalability is both reliable and secure.You will collaborate closely with product, infrastructure, and data teams to introduce new capabilities, enhance performance, and evolve the platform that supports our clients' most vital workflows. This high-impact position offers remarkable ownership, technical challenges, and opportunities for mentorship and leadership.

NOTE: This is a FULLY remote role, but candidates must be based within EMEA to effectively collaborate with their team, peers, and internal customers. Please apply only if you are physically located within EMEA.Hostaway is a trusted platform utilized by over 20,000 property managers globally, providing an AI-driven vacation rental management solution tailored for professional short-term rental operators. Our platform consolidates various functionalities to enhance efficiency and promote rapid growth.We are proud to be a profitable, high-growth company and the first unicorn in the short-term rental PMS sector . Join us at this exciting juncture! Discover more about our recent valuation and journey here.Role OverviewWe are seeking a dedicated Staff Backend Engineer with a focus on delivery to develop our new Trust Accounting subsystem. This is a unique opportunity to design and implement a financial system that property managers can rely on—ensuring accuracy, compliance, and reliability.Your contributions will significantly influence the financial operations of Hostaway's customers, helping them maintain compliant records and manage funds effectively.As a founding member of this team, you will steer the architecture and technical direction of this pivotal platform. From day one, you’ll shape architecture, processes, and delivery, fostering a culture that prioritizes correctness and accountability. Your efforts will directly impact Hostaway's ability to provide secure and auditable financial services to our customers.Key ResponsibilitiesDesign a Greenfield System: Take the lead in developing a new financial system from scratch, ensuring it meets the needs of our clients.

Join pod network in revolutionizing blockchain performance with groundbreaking innovations. If you have experience in optimizing systems for nanosecond-level precision and are eager to contribute to a global decentralized exchange ecosystem, this opportunity is designed for you.About the Role:We are in search of talented engineers skilled in high-frequency trading (HFT) or ultra-low-latency systems to architect and refine our execution and matching infrastructure. You will engage with the core runtime and networking stack that enables sub-millisecond order propagation and deterministic settlement across a distributed validator network.What You’ll Do:Develop and implement latency-sensitive components for the pod L1 and order book engine.Enhance network pipelines, serialization processes, and state access for optimal deterministic performance.Contribute to the development of new protocol primitives for timestamped execution and atomic batch auctions.Collaborate with researchers on incentive structures and cross-domain settlement methodologies.Qualifications:Proven experience in building or optimizing HFT systems, exchange matching engines, or low-latency trading infrastructure.Strong programming skills in systems languages such as Rust, C++, or Go.Comprehensive understanding of concurrency, networking, and performance profiling techniques.(Bonus) Familiarity with blockchain technology, consensus mechanisms, or distributed systems.What We Offer:Attractive salary packages.A high-impact role within a dynamic, growth-oriented startup.Opportunities for travel and visibility in thought leadership within the crypto community.About pod:Pod is an ambitious, early-stage Web3 startup focused on creating an innovative layer-1 protocol aimed at delivering a Web2-like experience within Web3 environments. Our team is designing a chainless, blockless, leaderless protocol that challenges traditional consensus paradigms. Discover more about pod network here.Backed by a16z crypto, 1kx, BBF, and Lemniscap, we are on the lookout for exceptional engineers to help shape the future of decentralized systems.

Please note: This position is FULLY remote, but applicants must reside within the European region to effectively collaborate with our team, peers, and internal stakeholders. We welcome applications from anywhere in Europe, but please ensure you are physically located within this region.Hostaway is a leading SaaS scale-up revolutionizing the vacation rental industry. We provide innovative solutions and maintain strategic partnerships with industry giants like Airbnb, VRBO, and Booking.com, allowing us to effectively compete and thrive. Our customer-centric values drive consistent results that foster growth, learning, and innovation for our team and clients.As a profitable, high-growth company, we are proud to be the first unicorn in the short-term rental Property Management System sector . Join us during this exciting phase of our journey! Discover more about our recent achievements and valuation here.About the Role:Hostaway is on the lookout for a dynamic and driven Staff Backend Engineer to join our Core team. This team is crucial for integrating with our primary partners (Online Travel Agencies). These integrations are vital to our customers’ daily operations, enabling seamless connectivity between their properties and major booking platforms. If you have experience working with similar tools that manage large volumes of data and interact with complex APIs, you will be an excellent addition to our team! As a Staff Engineer, you will lead the technical evolution of your domain, ensuring a comprehensive understanding of architectural challenges and strategies for resolution over time.Collaboration with the domain’s Product Manager is essential. While the PM focuses on the what, you will be their counterpart responsible for determining the how. Your ability to delve deep into the technical aspects will be invaluable.

Join GitLab as a Staff Backend Engineer specializing in Composition Analysis. In this role, you will have the opportunity to contribute to our mission of delivering the best DevOps platform in the industry. You will work collaboratively with a talented team, focusing on backend engineering, to enhance our products and services.

Phantom is revolutionizing the way people manage their finances with our cutting-edge money app, trusted by millions globally. Our platform seamlessly integrates the essential tools for managing, spending, and growing money into a user-friendly experience. We are dedicated to empowering users with the control and flexibility of cryptocurrency finance while eliminating unnecessary complexities from mainstream financial management.With a strong emphasis on security and user-centric design, Phantom offers sophisticated financial tools that are both powerful and accessible. This commitment to speed, control, and an exceptional user experience has propelled us to remarkable growth, garnering a community of over 20 million users, achieving the top spot in the Google Play Store finance category, and consistently ranking among the Top 50 apps across all categories worldwide.Role OverviewAs a Senior/Staff Backend Engineer, you will take charge of enhancing and maintaining the core authentication infrastructure that safeguards every Phantom account. Reporting directly to the Engineering Manager, you will lead the design, implementation, and operation of our fortified authentication stack, multi-factor authentication strategies, and advanced key-management services. Your contributions will significantly mitigate account takeover risks and provide robust identity solutions for all product teams.

At GitLab, we are revolutionizing the DevSecOps landscape with our intelligent orchestration platform. Our mission is to empower organizations to enhance developer productivity, streamline operations, mitigate security risks, and accelerate their digital transformation journey. With over 50 million registered users and a significant number of Fortune 100 companies relying on us, GitLab is trusted to deliver better, more secure software at speed.Our commitment to innovation is mirrored in our work culture. We leverage AI as a fundamental productivity tool, encouraging all team members to integrate AI into their daily tasks, fostering efficiency and innovation. At GitLab, your career can flourish, your ideas can thrive, and every voice is heard. Our high-performance culture, grounded in our values, promotes continuous knowledge sharing, enabling team members to unlock their full potential while collaborating with industry experts to tackle complex challenges. Join us in co-creating the future as we build technologies that redefine software development.Role OverviewAs a Staff Backend Engineer (Python) on the Duo Chat team within AI Engineering, you will spearhead the backend architecture that powers GitLab Duo Chat across our DevSecOps platform. Your role will involve addressing complex challenges in developing reliable, secure, and scalable AI-driven chat workflows, enabling our customers to plan, write, review, and secure code more efficiently and confidently. This is a hands-on technical leadership position where you will set the strategic direction for integrating and evolving large language model providers, such as Google Vertex AI, across Ruby on Rails and Python services, enhance our observability and testing practices, and guide the team through impactful technical decisions amidst ambiguity. In your first year, you will be expected to make pivotal architectural decisions, alleviate technical debt that hampers progress, and assist the team in delivering sustainable improvements in response quality, reliability, and maintainability.

Staff Backend Engineer – Transform Telecom InfrastructureAt OXIO, we are pioneering the world's first telecom-as-a-service (TaaS) platform, revolutionizing the telecom industry by enabling brands and enterprises to fully own and operate customized mobile networks tailored to meet their customers' needs. Our innovative TaaS solution merges various existing networks into a single, easily managed cloud platform, akin to a modern SaaS offering. With complete network access, businesses gain unprecedented insights into customer behavior and machine-to-machine (M2M) interactions. By focusing on continuous innovation, OXIO empowers companies to establish a robust telecom presence while extracting unique customer insights like never before.Job Overview:Mobile connectivity remains a critical resource globally, with significant disparities in affordability. For instance, acquiring 500 MB of data costs just 30 minutes of work for an American but 40 hours for a Mexican. Additionally, travelers often face exorbitant roaming fees or must navigate complex local carrier systems.The telecom industry is ripe for transformation. We propose a unified exchange platform where carriers, Mobile Virtual Network Operators (MVNOs), IoT providers, and device manufacturers can seamlessly trade connectivity. This initiative aims to reduce costs and unlock new experiences for both users and businesses.We are in search of a seasoned Tech Lead with extensive hands-on experience to guide the development of our flagship BrandVNO platform. In this pivotal role, you will lead the enhancement of our SDK, enabling clients to craft innovative telecom experiences directly within their mobile applications.

About RemoteRemote is tackling one of the most pressing challenges for modern organizations – navigating global employment compliance effortlessly. We empower businesses of all sizes to hire, compensate, and manage global teams seamlessly. Guided by our core values and a forward-thinking work culture, our team is dedicated to solving ambitious problems asynchronously from around the globe. You can find Remoters working from six continents (Antarctica is the final frontier!), and all of our job openings are fully remote.Innovation is at the heart of our values, and we have integrated Automation and AI capabilities into the requirements for every role.We invite every member of the Remote team to contribute their unique talents, experiences, and cultures to help us create a best-in-class HR platform. If you are dynamic, inquisitive, driven, and ambitious, we encourage you to join us and shape the future of work! Apply today!The RoleYou will be part of a diverse team of engineers specializing in Frontend, Backend, SRE, and QA, organized into cross-functional development teams focused on specific verticals.This position is available for multiple teams, and we will determine the exact team you will join during the interview process based on business requirements and your preferences.Regardless of the specific team, you will be responsible for developing tools, APIs, and integrations for one of our products.Our backend technology stack includes Elixir and Phoenix, supported by a Postgres database. We utilize React and Next.js for our frontend development. GitLab serves as our version control and CI/CD tool, while our applications are hosted on AWS. We rely on continuous integration for our deployments, allowing multiple deployments each day. You can explore our Engineering Rulebook for further insights.What You Can Expect from This RoleEngaging and meaningful challenges that empower individuals and businesses to operate globally.An opportunity to significantly influence our business as we are still early in our journey, meaning your contributions will have a lasting impact as the company grows.A great deal of flexibility in your work environment.

Twindo is pioneering the transformation of the remodeling, architecture, and interior design sectors through innovative AI and computer vision technologies. Our LiDAR-enabled iPhone and iPad scans generate accurate 3D representations of homes in mere minutes, delivering interactive models with precise measurements. Our proprietary technology converts these scans into detailed, editable as-built files in industry-standard formats. Our groundbreaking technology was showcased during Apple's keynote event when the LiDAR sensor was launched, and we are currently modeling millions of square feet every month.As a globally distributed, virtual-first organization, our team spans across various regions, with significant representation in the US and Europe.We are in search of a Senior Backend Engineer to contribute to the development and maintenance of our internal platform and tools, promoting business scalability and engineering efficiency. Reporting to the Platform Team Lead, this position involves a dynamic blend of foundational backend development and DevOps responsibilities, making it perfect for individuals who thrive on diverse projects. Collaboration with our iOS, Computer Vision, Visualization & Tooling, Web, Infrastructure, and Data engineering teams, as well as other departments, will be crucial.

Remote builds a platform that helps organizations manage global employment, making it easier for businesses to recruit, pay, and oversee international teams. The company’s fully remote structure brings together team members from six continents, each contributing unique perspectives to the ongoing development of Remote’s HR platform. Automation and AI are woven into daily work, supporting efficient and compliant operations. Role overview The Senior Backend Engineer joins a cross-functional group that includes Frontend, Backend, SRE, and QA specialists. Teams are organized by product vertical, and the specific assignment will be determined during the interview process based on both business needs and personal interests. The main focus of this role is building tools, APIs, and integrations for one of Remote’s core products. Key technologies Elixir and Phoenix for backend development Postgres as the primary database React and Next.js on the frontend GitLab for version control and CI/CD AWS for hosting Continuous integration enables frequent deployments throughout the day. For more detail on engineering practices, see the Engineering Rulebook. What this job can offer Challenging projects that support global collaboration between businesses and individuals Opportunities to make a direct impact as the company grows A supportive and flexible environment that values both personal and professional growth Location This is a fully remote position open to candidates anywhere in the world.

Join Raya as a Senior Backend Engineer, where your passion for backend engineering will be recognized and valued! We are looking for an experienced professional excited to work within a Node.js environment. The ideal candidate will possess over 6 years of progressive experience, showcasing both results and leadership capabilities in their previous roles. This is a pivotal moment for our backend team as we navigate through a phase of significant growth.At Raya, we believe in fostering a culture of learning and collaboration, empowering our team members to lead solutions to challenging problems and evolve into their best selves. You will play a crucial role in supporting our backend initiatives in messaging, connectivity, and location-based mapping projects. A successful candidate will demonstrate diligence in designing scalable software architecture and embrace Raya’s vision of enhancing lives through meaningful, in-person connections.We offer a robust benefits package that includes comprehensive medical and dental coverage, a daily food delivery allowance of $50, equity-based compensation, a vibrant company culture, ample learning opportunities, unlimited vacation, 12 weeks of paid parental leave, and an annual $1,000 travel stipend for personal growth and exploration, reflecting our core values of human connection, empathy, and curiosity.

LI.FI is at the forefront of revolutionizing multi-chain decentralized finance (DeFi) for traditional financial institutions, fintechs, and service providers. We provide a unified API that allows seamless access to all on-chain liquidity across major blockchains, ensuring optimal pricing for both same-chain and cross-chain swaps. Our dedicated team is on a mission to foster a more equitable and decentralized world. We prioritize user experience and strive to make complex technologies accessible to everyone.Overview of the RoleWe are seeking a Senior Backend Engineer who will play a pivotal role in the integration of Hyperliquid functionalities into our API platform. This backend-focused position allows you to influence core integrations at the infrastructure level, without the need for frontend or design tasks. The ideal candidate is passionate about Hyperliquid and its protocols, and is driven to enhance programmatic trading features (such as TWAP and perps) within the expansive DeFi ecosystem through high-performance backend systems.Note: Applicants must reside in the EMEA region. Submissions from outside this area will not be considered.Key ResponsibilitiesExpand LI.FI’s API capabilities by incorporating projects and features from the Hyperliquid ecosystem.Design, develop, and maintain backend services utilizing Node.js and TypeScript.Utilize MongoDB, Redis, and MySQL to facilitate high-throughput, low-latency trading operations.Collaborate closely with the Expansion Project Manager and fellow backend engineers to enhance integrations, optimize routing, and improve user flows, while also assessing new opportunities for feature development.Ensure the delivery of robust, high-quality backend code with a strong emphasis on scalability, performance, and reliability for both same-chain and cross-chain trading.Engage in code reviews, system design discussions, and maintain technical documentation.Qualifications for Success5+ years of experience in the cryptocurrency space, with a focus on building or integrating production-ready DeFi or trading systems.Solid backend engineering expertise, with hands-on proficiency in Node.js and TypeScript.Proficient in database management with MongoDB, Redis, and MySQL in high-performance backend contexts.Familiarity with Hyperliquid protocols and programmatic trading concepts is a plus.

About Us: At RelayProtocol, we are a pioneering Series A startup in the crypto space, dedicated to crafting innovative developer tools that facilitate token trading. Our vision is to empower developers in creating next-generation crypto applications by simplifying token integration and enhancing crypto commerce. We proudly support a myriad of crypto enterprises, including industry leaders like Magic Eden and Coinbase, across diverse sectors such as gaming, social interaction, and payments. Our team comprises deeply technical experts proficient in blockchain indexing, protocol design, and cross-chain interoperability. We are on the lookout for a driven Senior Backend Engineer to join our close-knit yet expanding team.Role Overview: We invite a highly skilled and seasoned Senior Backend Engineer with a robust foundation in crypto and/or financial technologies to elevate our team. In this pivotal role, you will be responsible for the design, development, and maintenance of the backend infrastructure for our cross-chain relayer product, ensuring its reliability and performance.Key Responsibilities:Backend Development: Architect, implement, and sustain highly scalable and resilient backend systems tailored for our cross-chain relayer. Optimize performance and responsiveness for large-scale data processing.Crypto Integrations: Engineer and uphold seamless integrations with various blockchain networks and crypto protocols, enhancing our platform's interoperability.

Why Clipboard Exists:At Clipboard, our mission is to empower individuals to ascend the socioeconomic ladder by transforming their extra time and ambition into meaningful career growth and financial opportunities. Our innovative app-based marketplace connects professionals with workplaces, enabling on-demand shift bookings that benefit both parties.About Clipboard:Clipboard is a rapidly expanding Series C company recognized as a leader in the Long Term Care sector, with plans to diversify into additional areas such as Dental Offices and Schools. As a YC Top Company, our global team of over 700 professionals operates remotely, having achieved profitability since 2022. We facilitate millions of shifts annually across the U.S., serving tens of thousands of professionals. Join us in our mission to further expand our impact. Learn more about our vision on our website here.Your Mission: Innovate, Execute, and Deliver ImpactAs a Backend Software Engineer at Clipboard, you will go beyond writing code—you will design solutions that redefine the connection between healthcare professionals and facilities. Collaborating with product managers, designers, and fellow engineers, you will develop impactful features that address real-world challenges. This is a dynamic and ongoing recruitment effort, as we consistently seek talented software engineers to join our growing team.What You’ll Do: Own the Code, Shape the FutureDeliver High-Quality, Scalable CodeCraft performant backend services utilizing Node/NestJS alongside responsive frontend features using React and TypeScript.Utilize MongoDB, Postgres, and Redis to maintain data integrity and optimize performance at scale.Develop Reusable Components and UtilitiesContribute clean, modular code for our web and mobile applications (Ionic/React, Dart/Flutter).Collaborate with the Developer Experience (DevX) team to enhance tools and libraries that increase productivity and streamline workflows.

Whippy is at the forefront of revolutionizing business communication through AI technology. Our innovative AI Agents are transforming the way companies interact with their customers, providing solutions across customer support, marketing, and sales. By leveraging Whippy’s Voice AI and Chat AI, businesses can automate manual workflows, effectively manage inquiries, nurture leads, screen applicants, and streamline high-value engagements at scale. Our all-in-one platform replaces outdated tools with a powerful solution that enhances productivity and efficiency.About the RoleJoin Whippy as a Backend Engineer and play a crucial role in our product development.You will:Design and implement highly scalable APIs for quick deployment of new products and services.Draft Engineering Requirement Documents to guide projects from concept to execution, ensuring thorough evaluation.Develop test suites to uphold product performance and reliability, integrating analytics to track the success of launched features.Our backend engineers have successfully built:A robust Public API and webhook interface handling millions of messages.An advanced query language built on top of Postgres and OpenSearch.A production-ready URL shortening service with custom domain capabilities.About YouYou possess a strong understanding of web API architecture and a commitment to producing high-quality, well-documented APIs.You are eager to engage in the entire project lifecycle, from initial research and planning through to implementation and performance monitoring.Your excellent written and verbal communication skills enable you to convey ideas, designs, and potential solutions effectively, primarily in an asynchronous environment.What We OfferWe offer a competitive compensation package ranging from $60K to $80K annually, commensurate with experience.You will have the opportunity to take significant responsibility and ownership of a groundbreaking product.Collaborate closely with experienced entrepreneurs who have successfully built companies valued over $100M.Important InformationAs a startup, our team dynamics are unique compared to larger organizations. We are a globally distributed team, and this structure fosters a distinct collaborative culture.

Join Kaizen Gaming as a Senior Backend Engineer and be part of a dynamic Agile team dedicated to crafting innovative solutions for millions of users worldwide. Collaborate with cross-functional teams to drive impactful projects, from user-facing applications to robust backend services, ensuring high performance and reliability. Your expertise will guide the development of scalable systems, turning complex requirements into elegant technological solutions.

Join Offchain Labs in our mission to revolutionize the decentralized application landscape. As a Senior Backend Engineer, you will play a pivotal role in enhancing blockchain scalability and security, helping us tackle real-world challenges while upholding the principles of decentralization, transparency, and security. Our team is composed of innovative thinkers and problem solvers eager to push boundaries and create a more equitable digital future. If you are passionate about blockchain technology and thrive in a dynamic environment, we want to hear from you!