Data Scientist/Engineer – Online Metrics at Perplexity | London

Join Perplexity, a pioneering company based in London, as we transform the way users search and engage with the internet. We are seeking seasoned Infrastructure Engineers to become integral members of our dynamic team. In this role, you will lead the design, implementation, and scaling of innovative tools, systems, and platforms that empower web, mobile, and browser engineers to develop cutting-edge products. Your contributions will be vital in enabling our product, AI, and development teams to innovate swiftly while ensuring utmost reliability, security, and performance at scale.Our Tech StackPython | Go | TypeScript | PostgreSQL | DynamoDB | Redis | FastAPI | React | Bazel | GitHub | AWSTeams HiringSenior/Staff PlatformThe Platform team is fundamental to ensuring product reliability, scalability, and performance at Perplexity. This elite team is responsible for developing and maintaining the critical infrastructure—from backend systems such as authentication, real-time data flows, and service orchestration to frontend frameworks that guarantee fast, reliable, and secure user experiences. By upholding stringent standards for code quality, uptime, and developer productivity, the Platform team enables all of Perplexity to innovate rapidly on a solid, well-designed foundation.Senior/Staff DevXThe Developer Experience (DevX) team is dedicated to empowering engineers at Perplexity to build, ship, and iterate faster than ever before. They manage internal platforms for source control, build, test, and deployment, effectively removing bottlenecks from each phase of product development. This team designs seamless onboarding, ultra-fast CI/CD pipelines, and developer tools that enhance creativity and safety at scale. Through collaborative efforts and significant autonomy, the DevX team amplifies the contributions of every engineer, facilitating rapid, dependable innovation across the organization.Senior/Staff Cloud InfraThe Cloud Infrastructure team architects and manages the essential cloud infrastructure that powers Perplexity’s global platform. This team designs and scales computing, storage, and networking systems to support high-throughput, low-latency workloads, balancing proactive project initiatives with operational support. Collaboration with product, AI research, security, and other teams ensures that our services remain consistently available, reliable, and responsive to user demands.

Join Perplexity, a pioneering firm serving millions of users daily by providing reliable and high-quality answers through an innovative LLM-first search engine combined with specialized data sources. Our Answer Quality team plays a crucial role in refining prompts, tools, searches, and specialized datasets, ensuring that our evaluations are fast, accurate, and actionable. In this exciting role, you will be instrumental in building the data flywheel that supports various teams across Perplexity.ResponsibilitiesDevelop and maintain systems and pipelines that empower Search, Product, and other teams to independently access reliable evaluation verdicts without delays.Take charge of the "evals-to-product" loop, autonomously transforming raw signals into robust datasets that drive decision-making throughout the organization.Construct a sophisticated simulator pipeline capable of replaying user interactions with the product in formats comprehensible to LLMs and VLMs, reflecting real-time product updates.Ensure data integrity by implementing monitoring, lineage tracking, and quality checks, providing downstream consumers with reliable results.Collaborate within a small, impactful team where your contributions will directly influence how Perplexity measures and enhances Answer Quality.

Join our innovative team at Perplexity as an AI Inference Engineer, where you'll be at the forefront of deploying machine learning models for real-time inference. Our technology stack includes Python, Rust, C++, PyTorch, Triton, CUDA, and Kubernetes. This is a fantastic opportunity to contribute to large-scale ML applications.Key ResponsibilitiesDevelop robust APIs for AI inference catering to both internal and external clients.Conduct benchmarking and resolve performance bottlenecks in our inference stack.Enhance system reliability and observability, responding effectively to outages.Investigate cutting-edge research and implement optimizations for LLM inference.

At Databricks, we're committed to empowering data teams to tackle some of the world's most challenging issues, including security threat detection and cancer drug development. Our mission is to create and manage the premier data and AI infrastructure platform so our customers can dedicate their efforts to the high-value challenges crucial to their missions. Our engineering teams develop cutting-edge products that meet significant real-world needs. We operate one of the largest-scale software platforms, comprising millions of virtual machines that generate terabytes of logs and process exabytes of data daily. Given our scale, we frequently encounter hardware, network, and operating system faults, and our software must effectively shield our customers from these challenges. The Delta DML team is responsible for the core write-path operations for Delta Lake, the open-source storage layer underlying the Databricks Lakehouse. Our goal is to deliver industry-leading performance and a seamless user experience at massive scale, with most data written in Databricks passing through our platform. We innovate in performance through features like Low Shuffle Merge and Deletion Vectors, and actively contribute to open-source initiatives that unify Delta and Iceberg formats. We are on the lookout for a highly skilled and experienced Senior Staff Software Engineer to join our backend team. In this pivotal role, you will design, develop, and maintain robust backend systems that power Databricks workspaces. You will work on building the next-generation platform for serving workspace assets, ensuring high queries per second (QPS), low latency, reliability, and performance while proactively addressing future growth challenges. As a senior member of the team, your responsibilities will also include providing technical leadership, mentorship, and guidance to junior engineers, thereby enhancing the overall coding practices and system designs of the team.

POS-22139This position offers flexible work options: Office, Hybrid, or Remote within the UKAt HubSpot, we are dedicated to equipping businesses with state-of-the-art AI technologies, and our AI Infrastructure group plays a pivotal role in this mission. We are looking for a Staff Software Engineer who is passionate about infrastructure and improving the developer experience to join our dynamic AI Serving team. This team is responsible for managing HubSpot's end-to-end model inference and serving infrastructure, ensuring that AI models are deployed reliably, scaled appropriately, and remain cost-effective across various environments, while also serving as the cornerstone for modern Python development at HubSpot.The AI Serving team is in charge of the frameworks and libraries that facilitate synchronous, asynchronous, and offline inference, including model deployment pipelines, autoscaling, and resource management for both GPU and CPU. Our roadmap is focused on enhancing batch inference reliability and efficiency, advancing model observability, and optimizing AI infrastructure costs. Additionally, we are the custodians of essential Python libraries and tools within HubSpot.As a Staff Software Engineer on the AI Serving team, your responsibilities will include:Developing and deploying production-level code that directly enhances AI capabilities across HubSpot, serving as a crucial component for user and business impact at scale.Driving the advancement of our model serving and inference infrastructure, with an emphasis on reliability, scalability, and cost efficiency.Setting the technical direction for deploying and operating ML models at scale, influencing decisions on architecture, cost management, and developer experience.Collaborating closely with Machine Learning Engineers, Product Software Engineers, and other Infrastructure teams to streamline model deployment and serving processes.Gaining in-depth exposure to a variety of HubSpot infrastructure systems by building and maintaining core Python libraries, providing an excellent opportunity to understand HubSpot's operations in detail.Engaging with HubSpotters across the organization—from engineering and product to design, research, marketing, and sales—to gain insights into how HubSpot functions as a business.Being encouraged to bring your authentic self to work and to choose a work style and location that enables you to perform at your best, whether that be from home, in an office, or a combination of both.We are not solely seeking engineers with extensive experience; we are looking for individuals who have demonstrated unique excellence, leadership qualities, and the ability to uplift those around them.

Perplexity is thrilled to introduce our Internship Program, designed for outstanding Master’s or PhD students specializing in Computer Science or Engineering in the UK for the 2025-2026 academic year. This immersive program offers a direct collaboration with our AI Inference team, providing a distinctive opportunity to acquire invaluable experience within a rapidly expanding AI startup. Exceptional interns may receive an offer for a full-time position upon completion of the program.Our AI Inference team is integral to the performance of Perplexity's products, overseeing the inference engine and deployments for models ranging from single-node embeddings to advanced distributed sparse Mixture-of-Experts models, all while managing extensive GPU clusters. With a focus on optimizing latency and throughput, the Inference team encompasses the entire serving stack, from GPU kernels to networking and monitoring infrastructure.

At Ripple, we are pioneering a future where value transfers seamlessly, akin to the flow of information. Our vision is ambitious, and we are already transforming the landscape. With our innovative crypto solutions tailored for financial institutions, businesses, governments, and developers, we are enhancing the global financial ecosystem, fostering economic equity, and creating opportunities for individuals worldwide. Join a team where you can engage in meaningful work while honing your skills in a supportive and collaborative environment.If you are eager to witness the tangible impact of your contributions and explore remarkable career advancement possibilities, we invite you to be part of our journey to create real-world value.At Ripple, we’re building a world where value moves like information does today. It’s big, it’s bold, and we’re already doing it. Through our crypto solutions for financial institutions, businesses, governments and developers, we are improving the global financial system and creating greater economic fairness and opportunity for more people, in more places around the world. And we get to do the best work of our career and grow our skills surrounded by colleagues who have our backs.If you’re ready to see your impact and unlock incredible career growth opportunities, join us, and build real world value.

About G2 - The CompanyG2 stands as the premier global software marketplace, renowned for empowering businesses to achieve their utmost potential through insightful data from genuine software users. By joining G2, you become part of an elite team dedicated to harnessing real user insights to influence strategic decisions.In an exciting merger with Capterra, SoftwareAdvice, and GetApp, we are now the largest repository of online software insights, catering to over 200 million visitors annually and featuring over 6 million verified reviews. Our goal is to enable software buyers to make informed decisions swiftly and confidently.We're just getting warmed up! Our mission is to revolutionize the global B2B software sector, establishing ourselves as the most reliable data source for software buyers and sellers in the AI era.Are you ready to embark on this thrilling journey with us? Join G2 as we scale new heights!About G2 - Our PeopleAt G2, our culture is deeply rooted in our PEAK values—(Performance + Entrepreneurship + Authenticity + Kindness). Being part of G2 means you are contributing to a value-driven, growing global community that supports each other in overcoming challenges and celebrating successes. Together, we tackle ambitious projects that foster personal and professional growth.You will collaborate with a diverse, global team comprising talented and dedicated individuals, each bringing unique experiences and aspirations. Our people-led ERGs play a crucial role in highlighting the diverse identities within our community. We prioritize DEI (Diversity, Equity, Inclusion) and philanthropic initiatives, such as our G2 Gives program, fostering a culture where we all strive to become better individuals.

Omaze connects communities in the UK and Germany with the chance to win luxury homes and life-changing prizes, while raising significant funds for charities. In just five years, Omaze has helped generate over £100 million for organizations including Age UK, the RSPCA, British Heart Foundation, and Great Ormond Street Hospital Charity. The company continues to grow, aiming to drive social impact on a global level. Role overview The Staff Software Engineer role at Omaze in London focuses on technical leadership and engineering strategy for platforms supporting social good. This position covers architectural design, software delivery, and team leadership. The engineer will influence both what gets built and how development happens, with a strong emphasis on developer experience, code quality, and sound engineering practices. What you will do Set and maintain engineering standards, patterns, and best practices across the stack, including TypeScript, AWS, and React. Lead the architecture of complex, cross-functional systems, making decisions that improve performance, scalability, security, and maintainability. Identify and address technical risks early, and drive architectural improvements that streamline processes and increase efficiency. Shape the company's approach to AI-assisted coding by evaluating tools, defining responsible integration standards, and embedding AI into workflows for CI/CD, code review, and testing. Guide the design of agentic systems, focusing on observability, human oversight, and safe autonomy limits. Translate broad business goals into actionable technical solutions. What sets Omaze apart Significant growth as a company with a mission-driven focus. Collaboration with a team committed to making a meaningful difference. Opportunities to work on innovative projects and initiatives. A culture that values hard work, mutual support, and shared success.

Join Us in Revolutionizing the Fashion Supply Chain!Each year, the fashion industry generates over 100 billion garments, with a staggering 60% ending up in landfills. This waste isn't due to lack of demand; rather, the secondhand fashion supply chain is outdated, manual, and inefficient.At Fleek, we are dedicated to transforming this reality. Our goal is to establish secondhand fashion as the preferred choice for consumers. We are developing an innovative infrastructure that empowers the global secondhand clothing market through a B2B marketplace and AI-driven systems that streamline the supply chain.Fleek enables vintage boutiques, online resellers, and retail buyers to access high-quality graded secondhand inventory directly from wholesalers and rag houses worldwide. Central to our operations is FleekSort, an advanced AI model specifically trained on secondhand fashion, capable of grading, pricing, and categorizing items using just a photo. This technology transforms what has traditionally been a fragmented and manual trade into a cohesive, searchable, and tradable global inventory system.Since our inception in 2022, we have successfully diverted 9 million items from landfills and have experienced consistent year-on-year growth. With approximately $50 million raised from distinguished investors including a16z, Y Combinator, Burda Principal Investments, and HV Capital, we have recently completed our Series B funding round. Our advisors and private investors include industry veterans from Depop, Shopify, and Postmates.Currently, we serve thousands of resellers and retailers across the UK, Europe, and the US. With the secondhand fashion market projected to soar to $350 billion by 2027, Fleek is poised to become the AI-driven operational and financial backbone of secondhand commerce on a global scale.We are in search of passionate individuals eager to build impactful solutions and thrive in a fast-paced environment. If this excites you, continue reading!About This RoleAs the most senior engineering position within our organization, you will oversee the Demand product, which is crucial for driving revenue, growth, and customer engagement across mobile, web, and backend platforms. You will lead a talented team of approximately five engineers based in London, report directly to our CTO, Sanket Agarwal (formerly of Google and Postmates), and collaborate closely with our Product and Design teams.You will be responsible for everything that affects buyer conversion, retention, and growth speed.Why This Role Is UniqueAt Fleek, the Demand function is our most commercially vital area. You will not merely offer advice as a Staff engineer; you will have ownership over the entire system that transforms supply into revenue.Fleek is at the forefront of digitizing an industry that has yet to embrace technology. There are no established guidelines for creating a transaction layer around secondhand fashion at a wholesale scale, where each item is distinct...

About Us:Lunar is an innovative technology company operating in stealth mode, dedicated to developing a transformative software platform for health systems. Our mission is to redefine healthcare with state-of-the-art, AI-driven software that empowers hospitals to provide exceptional care to their patients. Our platform serves as the foundational backbone of modern health systems, revolutionizing clinical and operational workflows on a large scale with the world’s first AI-native hospital information system.This next-generation platform represents a thorough reconstruction of the information infrastructure that supports health systems. From doctors and nurses to pharmacists, lab technicians, coders, billers, and supply chain personnel, as well as patients, Lunar’s software is designed to enhance every aspect of healthcare delivery. We view this challenge as the 'moon landing' of healthcare—an ambitious undertaking that many deem impossible.Supported by leading venture capital firms from Silicon Valley, we champion the effectiveness of a compact, high-performing team of experienced professionals working at the top of their game. We seek individuals who are driven, inquisitive, possess sound judgment, and are committed to producing the best work of their careers.Our hospitals operate on Elixir. We have adopted Elixir for its fault tolerance, concurrency, and scalability—critical attributes for managing real-time patient data in essential environments such as Emergency Departments, ICUs, and Operating Rooms.We are on the lookout for a Staff Software Engineer who is eager to confront some of the most challenging technical issues in healthcare and do so as part of a small, agile, and purpose-driven team. If you take pride in writing clean, resilient code and are enthusiastic about reinventing the software infrastructure for contemporary hospitals, we would love to connect with you.Key Technical Challenges You May Encounter in Your First Six Months:Building a Modern Cloud Architecture from the Ground Up: We have no legacy systems to unravel. We are designing a cutting-edge cloud-native platform centered around Elixir.Developing a Superior Access Control System for Clinical Data: Create a modern access control system with precise permissions that honor clinical data structures and patient data ownership while facilitating population-level insights for enhanced public health.Ensuring Hospitals Remain Operational 24/7: Design and implement infrastructure capable of supporting rolling deployments, failover, and...

About H Company H Company pursues advances in superintelligence with a focus on agentic AI. The team works to automate complex, multi-step tasks that typically require human involvement, aiming to expand what people can achieve. H Company values curiosity, responsibility, and a commitment to safety in AI. The culture emphasizes openness, ongoing learning, and collaboration, with each person’s input recognized and appreciated. Infrastructure Team Overview The Infrastructure team provides researchers and engineers with the resources they need to do their best work. This group maintains the core infrastructure behind H’s public services, building systems that are reliable, scalable, and ready for growth. Team members shape everything from foundational models to agent systems and public-facing services.

Our MissionAt Omnea, we are transforming the enterprise business landscape by addressing the most challenging aspects of procurement. Our aim is to streamline the purchase process, which often drags on for months, involves numerous emails, and requires input from various departments such as Finance, Legal, Security, and IT for approvals.With the backing of $75M from Khosla Ventures, Insight Partners, and Accel, we are revolutionizing this space. Our AI-driven platform integrates every stakeholder, step, and system to ensure that buying is swift, secure, and efficient—providing a singular destination for requests, automated approvals and renewals, real-time supplier risk analysis, and complete visibility of spending.This sector represents a $7B+ untapped market, and our growth trajectory underscores the potential: we have increased our ARR tenfold to double-digit millions in just 18 months, earning the trust of global enterprises like Spotify, MongoDB, Monzo, and Albertsons. Currently, we are recognized as the 4th fastest growing startup in Europe.Our team has previously scaled Tessian (cybersecurity technology backed by Sequoia, Balderton, Accel, and acquired post-Series C). We comprise ex-founders and operators who have successfully grown unicorns and delivered world-class products. You will collaborate with seasoned leaders like Ben, Abs, Sabrina, and Rebe.What We're Looking ForWe are on the lookout for an outstanding, product-oriented Staff Software Engineer (L4) to be a pivotal part of our engineering team and propel Omnea into its next growth phase. In the upcoming year, our team will double in size, our enterprise customer base will expand from around 100 to over 200, and our revenue is projected to triple. This role is for a senior individual contributor focused on domain-level impact, where you will utilize your deep technical expertise to influence systems, architecture, and product outcomes—without formal team leadership or people management obligations.You will join us at a critical juncture. We have recently secured $50M in Series B funding from ....

About H:H is at the forefront of advancing superintelligence through agentic AI. Our mission is to automate complex, multi-step tasks usually undertaken by humans, empowering AI agents to unlock the full potential of human capabilities.We are on the lookout for the brightest AI minds who are as committed to building safely and responsibly as they are to pushing the boundaries of disruptive agentic technologies. At H, we foster a culture of openness, continuous learning, and collaboration, where every voice contributes to our shared success.About the Team: The Infrastructure team is dedicated to providing seamless access to the necessary infrastructure for our research and engineering teams. We ensure that the foundational infrastructure for our public services is robust, reliable, and scalable, positioning Infra team members to influence every aspect of H, from foundational model development to agent creation and public service delivery.Key Responsibilities:Design and manage infrastructure to support:Research initiatives in model and agent development, including training infrastructure, data pipelines, and inference capabilities.Product engineering efforts on H's agent platform, encompassing client-facing APIs and agent runtimes across multiple deployment scenarios (multi-tenant and on-premises).Establish and maintain observability and monitoring strategies.

Who We AreSamsara (NYSE: IOT) is at the forefront of the Connected Operations™ Cloud, a transformative platform that empowers organizations reliant on physical operations to capitalize on Internet of Things (IoT) data. Our mission is to enhance the safety, efficiency, and sustainability of the foundational sectors driving the global economy. Representing over 40% of global GDP, these industries—including agriculture, construction, field services, transportation, and manufacturing—are critical infrastructure, and we are excited to lead their digital transformation.Joining Samsara means you will play a vital role in defining the future of physical operations. You'll collaborate with a dynamic team focused on developing innovative product solutions such as Video-Based Safety, Vehicle Telematics, Apps and Driver Workflows, and Equipment Monitoring. As a recently public company, we provide the autonomy and support needed to make a significant impact as we build for the long term.About the Role:In this newly established Staff Software Engineer position, you will design the technical architecture necessary for global fleet sustainability, focusing on digitizing the vast transport and infrastructure sectors that support our world. Our goal goes beyond traditional cost-saving measures; we prioritize resource efficiency on a global scale.At Samsara, our Staff Engineers are proactive technical leaders who integrate high-level architectural strategies with a determined builder mindset. They operate with empowered autonomy, addressing the most complex challenges at the intersection of physical and digital operations.Unlike conventional architects, they maintain a close connection to the implementation, actively contributing to the codebase to foster rapid innovation and sustain development momentum. Their leadership serves as a force multiplier, elevating the technical capabilities of the team through insightful mentorship and pragmatic decision-making, ensuring that every line of code has a measurable impact on the world’s essential industries.In this role, you will spearhead the technical strategy for our Sustainability suite—transforming raw, inconsistent sensor signals into high-fidelity data for precise energy monitoring, and constructing the intricate global infrastructure necessary for fleet electrification.

At Databricks, we are dedicated to empowering data teams to tackle some of the world's most challenging problems — from revolutionizing transportation to advancing medical innovations. We achieve this by developing and operating the world's leading data and AI infrastructure platform, enabling our customers to harness deep insights from data to elevate their business outcomes. Founded by engineers and driven by customer obsession, we seize every opportunity to confront complex technical challenges, whether it's crafting next-generation UI/UX for data interfaces or scaling our services and infrastructure across millions of virtual machines. Our journey has only just begun. Our engineering teams are at the forefront of creating impactful products that address significant global needs. We operate one of the largest-scale software platforms, managing millions of virtual machines, generating vast amounts of logs, and processing exabytes of data daily. Given our scale, we frequently encounter cloud hardware, network, and operating system faults, and our software must seamlessly shield our customers from these challenges. Unity Catalog serves as our platform's native unified and open governance solution for data and AI. It eradicates silos, streamlines governance, and accelerates insights at scale. We are seeking a Senior Staff Software Engineer to lead the technical direction of Unity Catalog Runtime Enforcement. In this role, you will build and fortify the runtime enforcement layer for Unity Catalog, guaranteeing secure and consistent authorization and data access across Databricks compute, engines, and cloud environments. This initiative aims to reduce incidents and simplify customer choices by unifying enforcement semantics.

Join physicsx as a Senior Software Engineer specializing in Site Reliability Engineering (SRE). In this pivotal role, you will be responsible for enhancing our core infrastructure, ensuring reliability, scalability, and performance of our software systems. You will work with a talented team to design, implement, and maintain robust solutions that meet the needs of our users.As a senior engineer, you will also mentor junior team members, contribute to architectural discussions, and drive best practices in software development and operations.

At Ripple, we are pioneering a transformative world where value transfers seamlessly, akin to the flow of information in today's digital landscape. Our vision is ambitious and impactful, and we are already making strides toward this goal. Through our innovative cryptocurrency solutions tailored for financial institutions, businesses, governments, and developers, we are enhancing the global financial ecosystem, fostering economic equity, and expanding opportunities for individuals across the globe. Join us to achieve remarkable professional growth and make a significant difference in the world of finance.If you are eager to witness your contributions in action and unlock exceptional career advancement opportunities, come aboard and help us create authentic value in the real world.The RoleAs a Staff Engineer specializing in Front End development, you will contribute to Palisade, Ripple's flagship wallet-as-a-service platform. This platform empowers businesses, fintech firms, and banks to create innovative digital asset treasury, payment, and exchange solutions.

Ebury is on a mission to empower ambitious businesses to achieve global growth. We extend the same philosophy to our team members, promoting innovation, collaboration, and problem-solving in an inclusive environment where everyone feels valued, supported, and empowered to thrive.If you are a collaborative individual eager to revolutionize global business operations, we encourage you to reach out. Join us at Ebury and accelerate your career while shaping the future of finance.Join Our Team as a Staff Software Engineer (Enabling Teams)Location: London Office - Hybrid: 4 days in the office, 1 day remoteEbury is seeking highly skilled and motivated Staff Software Engineers to enhance our engineering division in London. This is a remarkable opportunity to make a significant impact within a leading FinTech firm. As a Staff Software Engineer, you will be a crucial member of our team from day one, contributing to mission-critical projects and deploying production code within your first week. Your role will involve collaboration with various product squads alongside Engineers, Product Designers, and Product Managers. We expect you to tackle complex challenges and guide your team to make informed trade-offs. You will be immersed in both the intricate details and the overarching vision of our projects. Additionally, you'll play a pivotal role in engineering leadership and cultivate strong relationships with stakeholders across the organization. We are committed to identifying and nurturing future technical leaders; for those who exhibit exceptional performance and potential, we offer an accelerated career progression path.