Senior Software Engineer - Platform at Longshot Systems | London

Join a Revolutionary CompanyAt Palantir, we develop cutting-edge software that drives data-informed decision-making and operational efficiency. Our innovative platforms enable partners to create life-saving pharmaceuticals, anticipate supply chain challenges, locate missing individuals, and much more.Your RoleAre you passionate about crafting exceptional platforms that facilitate mission-critical software deployment at scale? Apollo is at the forefront of autonomous software management and continuous deployment, spanning on-premise solutions, diverse cloud providers, isolated environments, and stringent accreditation frameworks such as IL-5 and FedRAMP, extending even to edge computing. Discover the challenges Apollo addresses on our blog or view our Apollo demo.As a Software Engineer on the Apollo platform, you will develop software solutions that redefine how organizations worldwide implement software. Your work will support mission-critical software for both Palantir and our clients across commercial and government sectors.We seek individuals with a curious mindset, a strong commitment to engineering excellence, and the ability to thrive in a dynamic environment where innovative ideas are celebrated. Apollo Software Engineers engage in all phases of the product lifecycle, from ideation and design to prototyping, execution, and deployment. You will collaborate closely with both technical and non-technical team members to understand customer challenges and deliver effective solutions.This position welcomes candidates of all experience levels.

Join Multiverse as a Senior Software Engineer specializing in Platform Engineering. In this pivotal role, you will leverage your expertise to design, build, and enhance our platform, ensuring it meets the highest standards of performance and reliability. Collaborate with cross-functional teams to deliver robust solutions that drive the success of our innovative programs.

At Fastly, we are dedicated to enhancing connectivity to the digital experiences that matter most to our users. Our cutting-edge edge cloud platform empowers our clients to rapidly and securely deliver exceptional digital solutions by processing, serving, and securing applications close to their end-users — right at the edge of the Internet. Built to leverage the modern internet, our platform is highly programmable and supports agile software development, serving a roster of prestigious clients such as GitHub, Yelp, Paramount, and JetBlue.Join us in our mission to create a more trustworthy Internet.Posting Open Date: 24 March, 2026Anticipated Posting Close Date*: 20 April, 2026*Job posting may close early due to the volume of applicants.Staff Software Engineer, Compute PlatformOur team is responsible for developing the Compute platform at Fastly — an advanced serverless solution built on open standards operating on our extensive global edge network. This platform meets the demands of modern application development, enabling customers to execute code in a secure environment with microsecond cold start times, at scale, right on the edge.We are seeking a talented Staff Software Engineer to join our dynamic team and help enhance our hosting infrastructure. This role will encompass essential networking and systems-level tasks, as well as cross-team collaboration and the design of high-quality APIs for our customers to leverage services developed by other teams. You will also have the opportunity to contribute to influential open-source projects (such as Wasmtime) that play a pivotal role in our Compute vision.What You'll Do:Facilitate seamless communication and coordination among team members and across various technical and product teams.Engage in code reviews to enhance the codebase and improve team processes.Lead projects from a technical standpoint, driving progress and keeping stakeholders informed on project status.Develop platform-level code in Rust that addresses host concerns such as back pressure, resource limits, and service interactions.Investigate and resolve performance and stability challenges to meet stringent scalability requirements.Take ownership of a large-scale production system characterized by exceptional performance and availability needs.

About Neko Health Neko Health focuses on shifting healthcare from treating illness to preventing it. By combining non-invasive technology with clinical expertise, the company delivers early health insights that help people take action before problems escalate. Director of Software Engineering (Platform) – London Role Overview This Director-level role leads the engineering efforts behind Neko Health’s core platform. The platform underpins health data management, member records, and system reliability for both clinics and internal products. Platform stability is essential, outages or failures can disrupt clinic operations and affect patient care. The Director will drive the delivery of an AI-first platform, focusing on resilience and scalable performance to support rapid organizational growth. Key Focus Areas (First 6–12 Months) Design and implement a secure, scalable infrastructure platform on Azure for health and member data. Accelerate product deployment cycles by improving the underlying platform. Increase system reliability and reduce operational incidents that could impact clinics. Grow and lead a high-performing platform engineering team (initially 10–15 engineers). Work closely with Product and Data teams to shape the long-term platform strategy.

Join our dynamic team at physicsx as a Senior Software Engineer focused on Platform Operations. In this role, you will be instrumental in enhancing our platform's performance and reliability, ensuring exceptional user experiences. You will collaborate with cross-functional teams to design, develop, and implement robust software solutions that meet the evolving needs of our users.

Join our dynamic team at PhysicsX as a Senior Software Engineer specializing in Platform Runtime. In this pivotal role, you will lead the design and implementation of our software platform, ensuring high performance and scalability. Collaborate with cross-functional teams to create innovative solutions that drive the future of technology.

Join Algolia, a trailblazer and market leader in AI Search, where we empower over 17,000 businesses to deliver rapid, predictive search and browsing experiences at an internet scale. Every week, we handle more than 30 billion search requests—surpassing the combined total of Microsoft Bing, Yahoo, Baidu, Yandex, and DuckDuckGo.In 2021, we secured $150 million in Series D funding, elevating our valuation to $2.25 billion. This robust foundation allows us to continually invest in our top-tier platform and support exceptional clients like Under Armour, PetSmart, Stripe, Gymshark, and Walgreens.Algolia was designed to enhance user experiences by providing an intuitive search-as-you-type functionality for websites and mobile applications. Our search API is utilized by thousands of clients across 100+ countries, and billions of queries are resolved monthly thanks to the code we deploy daily.We are on the lookout for a Software Engineer to become part of our Metis team. This team manages Metis, our cloud-based scalable architecture for NeuralSearch, our cutting-edge AI search engine that integrates both keyword and vector search capabilities. The Metis system is composed of distributed components that manage the building and storage of indices containing customer data, subsequently querying that data to deliver search results. This role demands a deep understanding of and the ability to address challenges associated with complex distributed systems.Our team comprises engineers from diverse backgrounds, many of whom work remotely. Your unique experiences, knowledge, and perspectives will contribute to our diversity and drive the development of impactful products.

Application Deadline: We are actively conducting interviews and are eager to fill this role as soon as we find the right candidate.ABOUT THE OPPORTUNITYWe are in search of talented Backend Software Engineers who are passionate about developing tools that enhance frontier AGI safety research. This includes creating and maintaining evaluation libraries and tools that enable monitoring and control of our LLM traffic.REPRESENTATIVE PROJECTSAs part of your role, you may work on the following projects within your first six months:Internal tools for efficient running and analysis of evaluations, such as a system that investigates thousands of agentic evaluation runs in parallel and automatically surfaces insights.Automated evaluation pipelines designed to streamline the process from accessing a new model for pre-deployment testing to analyzing key results and disseminating them.Orchestration tools enabling researchers to execute thousands of agentic evaluations in parallel on secure remote machines.LLM proxy services that allow real-time monitoring of our coding agent traffic, supporting automatic identification of undesired behaviors.Development of LLM agents and MCP tools that automate internal software engineering and research tasks, with safeguards to prevent significant failures.Continuous Integration (CI) pipeline optimizations to enhance execution speed and eliminate unreliable tests.Telemetry API and enhanced instrumentation of existing tools to monitor usage and improve reliability.A data warehousing pipeline to store thousands of evaluation transcripts for research and dataset building.Improvements to the Inspect framework and ecosystem, including support for modern agentic scaffolds.

About OLIXAt OLIX, we are at the forefront of a technological revolution, creating the next-generation Optical Tensor Processing Unit (OTPU) that promises unmatched performance and energy efficiency. As AI rapidly evolves, we recognize the urgent need for innovative solutions that surpass outdated infrastructure. OLIX is dedicated to bridging the gap in AI capabilities, positioning ourselves as a leader in the next economic opportunity of the century.Role OverviewIn the role of Software Engineering Director - Platform Integration, you will spearhead a dynamic team of over 30 engineers and 5 managers across critical domains, including cluster orchestration, platform management, networking, and field engineering. Your leadership will be pivotal in ensuring OLIX’s systems function as a robust hyperscale AI infrastructure.We seek a visionary engineering leader who can shape OLIX’s trajectory and instill a culture of excellence. You will leverage your profound technical acumen to craft high-performing teams that operate with agility and purpose, establishing the technical roadmap that drives our company towards its objectives.Key ResponsibilitiesDefine and communicate a clear vision for Platform Integration, ensuring accountability across cluster orchestration, fleet management, networking, and deployment.Cultivate a high-performing organization by mentoring managers to prioritize customer outcomes and reliability.Establish standards for technical excellence, including architectural principles, review processes, and quality benchmarks.Guide the technical strategy for distributed AI workloads, making informed decisions on investments in cluster orchestration and management systems.Translate OLIX’s long-term business goals into actionable priorities that enhance customer and business outcomes.Foster a vibrant culture emphasizing innovation, speed, and operational excellence.QualificationsProven engineering leadership experience in software development and systems integration.Deep technical expertise in AI infrastructure and distributed computing.Exceptional communication and interpersonal skills, capable of inspiring teams.

Role Overview Writer is hiring a Senior Software Engineer to help build and improve our Enterprise AI Platform. Based in London, this role centers on designing and developing software that supports efficiency and better user experiences for a range of clients. What You Will Do Develop and maintain software for our Enterprise AI Platform Work with cross-functional teams to deliver reliable and scalable solutions Contribute ideas and technical expertise to shape the direction of AI products at Writer Collaboration This position works closely with engineers, product managers, and other teams to ensure our software meets client needs and quality standards. Your input will help guide the evolution of AI tools within the company.

About the Role Saturn is looking for a Platform Engineer in London. This role focuses on building and improving the platforms that power our products. The work centers on designing systems that scale, run efficiently, and support a growing user base. What You Will Do Develop and optimize core platform components Work closely with other engineers to deliver reliable systems Contribute to the design of scalable solutions that handle increasing demand Team and Collaboration Platform Engineers at Saturn collaborate with a skilled engineering team. The group values practical solutions and a shared commitment to quality.

About the TeamAt OpenAI, our Platform Systems team is at the forefront of innovation, merging advanced AI technologies with large-scale distributed systems. We create the engineering and research infrastructure essential for training OpenAI’s premier models on some of the world's most powerful, custom-designed supercomputers.Our dedicated team develops critical model training software, delving deep into the technical stack to enhance collective communication, optimize compute efficiency, refine parallelism strategies, and improve fault tolerance, failure detection, and observability. The systems we engineer are pivotal to accelerating OpenAI’s research, ensuring reliable and efficient training at the cutting edge of technology.We foster close collaboration with researchers throughout the organization, consistently integrating insights from across OpenAI to advance our training platform.About the RoleAs a Software Engineer specializing in Platform Systems, you will architect and develop distributed systems that enhance visibility into large-scale training workloads, ensuring their reliable operation at scale.Your responsibilities will include engineering failure detection, tracing, and observability systems to identify suboptimal or malfunctioning nodes, revealing performance bottlenecks, and enabling engineers to optimize extensive distributed training jobs. This infrastructure is vital for the functionality of OpenAI’s training stack and is continuously evolving to accommodate new use cases and increasingly intricate workloads.This position is central to our training infrastructure, merging systems engineering, performance analysis, and large-scale debugging.In This Role, You WillDesign and implement distributed systems for failure detection, tracing, and profiling large-scale AI training tasks.Create tools to detect slow, faulty, or erratic nodes, providing actionable insights into system performance.Enhance observability, reliability, and performance across OpenAI’s training framework.Diagnose and resolve challenges in complex, high-throughput distributed environments.Collaborate with systems, infrastructure, and research teams to elevate platform capabilities.Adapt and extend failure detection and tracing systems in support of new training methodologies and workloads.You Might Thrive in This Role If YouPossess a strong passion for performance, stability, and observability in distributed systems.Have experience with large-scale systems and are excited to tackle complex challenges in AI infrastructure.

Join Algolia as a Senior Software Engineer specializing in User Interface and Connectors Platform. In this pivotal role, you will contribute to the development of innovative UI solutions that enhance user experience across our platform. Collaborate with a talented team of engineers to design, implement, and optimize various connectors, ensuring seamless integration with our services.We are looking for a candidate who is passionate about technology, thrives in a fast-paced environment, and is eager to push the boundaries of what is possible in software engineering.

Who Are We?Postman is the premier API platform, utilized by over 45 million developers and 500,000 organizations, including 98% of the Fortune 500. We empower developers and professionals worldwide to create an API-first ecosystem by simplifying each phase of the API lifecycle and enhancing collaboration, allowing users to build better APIs, faster.Headquartered in San Francisco, we maintain offices in Boston, New York, Austin, Tokyo, London, and Bangalore—where Postman originated. As a privately held company, we are backed by esteemed investors including Battery Ventures, BOND, Coatue, CRV, Insight Partners, and Nexus Venture Partners. Discover more at postman.com or connect with us on X via @getpostman.P.S: We recommend exploring The "API-First World" graphic novel to grasp our broader vision at Postman.The OpportunityThe Client Platform team is on the lookout for a Senior Frontend Engineer to elevate our UI Platform standards and enhance our frontend ecosystem. You will champion engineering excellence through refined architecture, performance enhancements, and sustainable coding practices, ensuring our platform provides outstanding experiences.Collaborating with fellow senior engineers, you will oversee various components of our UI Platform (including design systems, accessibility, internationalization, theming, etc.). This represents a unique chance to make a significant impact on the foundation that hundreds of Postman engineers and our 40+ million customers rely on daily.What You’ll DoThe Client Platform team is a global engineering unit responsible for establishing a streamlined environment for all Postmanauts to develop and deploy web applications. Our platform serves as the backbone for over 240 engineers at Postman who depend on it to launch new features and enhancements to more than 40 million users.Design and implement scalable, maintainable front-end solutions, focusing on the presentation layerDesign system and component libraryApplication shell & layoutSpecialized UI components (code editor, text editor, data grid)Global UI patternsAccessibilityInternationalization/localizationTheming/styling architecture

Join Wise, a leading technology company, as a Senior Software Engineer specializing in our cutting-edge marketing platform. In this role, you will be instrumental in designing, developing, and optimizing features that enhance our customer experience and drive engagement. Collaborate with a talented team of engineers and product managers to deliver scalable solutions that align with our business goals.

Join a Revolutionary CompanyMeticulous is transforming the software development landscape at an unprecedented pace. We have created the world's first fully autonomous and comprehensive testing platform specifically for frontend codebases—a groundbreaking capability that we believe is essential for unleashing the full potential of code generation.Our innovative solution has garnered significant interest, with renowned companies such as Dropbox, Wiz, and Notion often prioritizing Meticulous over other software products in their stack. Our dedicated team of eleven, featuring exceptional engineers from esteemed organizations like Uber, Google, Dropbox, GitHub, Meta, and Palantir, has made this success possible.Discover more about our mission in this video here.Your RoleBe Our First Platform EngineerAt Meticulous, we analyze thousands of recorded user sessions for each pull request, necessitating robust and scalable infrastructure that is both fast and cost-effective.As the first dedicated Platform Engineer, you will take ownership of the systems enabling this capability. Your responsibilities will encompass designing and constructing resilient infrastructure to accommodate significant growth, managing its production operations, and shaping our incident response processes. This is not merely a maintenance position; you will be instrumental in defining our operational and architectural strategies as we expand.Enjoy substantial autonomy in this role. As a key member of a small team, your architectural decisions will directly influence our infrastructure development, allowing you to innovate rather than simply execute predefined designs.Key ResponsibilitiesYour contributions will drive our platform engineering initiatives, spanning infrastructure, security, and developer experience:Designing Robust Infrastructure: Architect, build, and scale the compute platform that powers Meticulous, effectively managing our cloud resources through Terraform while maintaining rigorous change management protocols. Optimize infrastructure costs while balancing performance and expenditure as we grow.Ensuring Production Reliability: Enhance our monitoring, alerting, incident response, and on-call protocols to guarantee swift and effective resolution of system issues.Developing Production Code: Integrate platform engineering with general software development tasks, contributing code that extends beyond mere infrastructure.

At Klaviyo, we celebrate the diverse backgrounds, experiences, and perspectives that each of our team members bring to our collaborative environment. We believe in empowering every individual to achieve their potential, and we value the unique contributions that extend beyond conventional job criteria. If you find yourself closely matching our profile, we encourage you to apply. To explore our vibrant culture, visit klaviyo.com/careers to discover how we empower creators to shape their destinies.Why You Should Join the Internationalization Platform TeamThe Internationalization (i18n) Platform team is responsible for all aspects of creating, processing, and delivering internationalization features for Klaviyo users. As a Senior Software Engineer, you will play a pivotal role in mentoring and driving complex, multi-component projects within the i18n platform. Your contributions will be essential in managing translations, rolling out new localization features, accommodating multiple currencies, and refining our internationalization processes.Joining our highly technical team means engaging with professionals who possess significant domain expertise. We manage tools and services that are integral to the organization, spanning from frontend user interfaces to backend data infrastructure. Our team orchestrates several services that facilitate the translation pipeline in collaboration with our localization experts.Looking ahead to the next 6-12 months, we are committed to enhancing our capabilities by implementing large language model (LLM) workflows for improved translation efficiency, expanding the availability of our Smart Translations product, and developing innovative features to support currency handling across various regions. Why You Should Join UsWe cultivate a culture that prioritizes psychological safety, collaboration, and work-life balance, offering flexible working hours and structured on-call rotations.Emphasizing a “you make it, you support it” philosophy, we expect engineers to provide on-call support for our products in the event of incidents. We compensate for on-call rotations and aim to minimize incidents that require call-outs. New engineers will gradually transition into the on-call rotation, typically joining after their first six months of comprehensive training.

Applications are accepted on a rolling basis, and we highly recommend early submissions.ABOUT APOLLO RESEARCHApollo Research is an innovative and rapidly expanding company specializing in AI safety and model evaluation, offering third-party assessments for cutting-edge AI models. As the capabilities of AI technologies advance at an unprecedented pace, we recognize both the immense opportunities they present and the significant risks associated with their misuse and misalignment. At Apollo Research, our primary focus is on deceptive alignment—situations where AI models appear to be aligned with human values but are, in reality, misaligned and capable of circumventing human oversight.We foster a culture that prioritizes truth-seeking, goal orientation, constructive feedback, and a friendly, supportive environment. For more insights into our workplace culture, feel free to click here.ABOUT THE ROLEAs the first full-time legal hire at Apollo, you will have the unique opportunity to establish and lead our legal and compliance functions from the ground up. This role encompasses the development of scalable systems and processes across the UK, US, and select EU jurisdictions. You will balance strategic leadership with hands-on execution across various domains, including commercial contracting, corporate legal matters, employment/HR, IP protection, statutory reporting, fundraising support, and compliance management (75% operational expansion and 25% compliance oversight). Reporting directly to the COO, you will have the potential to evolve into the General Counsel role as the legal department grows. Ideal candidates may come from in-house legal roles at AI and tech startups or from established law firms or large technology companies seeking greater ownership and impact. You will be responsible for designing and owning Apollo’s legal function from the ground up.

Application Deadline: We are actively conducting interviews and aim to fill this position promptly once we identify a suitable candidate. ABOUT THE ROLEWe are in search of talented Full-Stack Software Engineers who are passionate about developing tools for advanced AGI safety research. Your role will involve building and maintaining evaluation libraries and tools to monitor and manage our LLM traffic.KEY PROJECTSYour primary responsibility will be to create tools for analyzing model evaluation results. Here are some features you might develop and implement within your first 6 months:- LLM-driven search functionality to locate intriguing segments in evaluation transcripts.- Comparative views that illustrate discrepancies in conversations and scores across two evaluation runs.- Capability to view and analyze dialogues with coding agents (e.g., Cursor, Claude Code) alongside evaluation transcripts.- Real-time streaming of results for ongoing evaluations.- Collaborative editing of evaluation logs that automatically updates metrics and other derived data.Consider this as crafting an 'IDE for evaluations'.In addition to the main projects, you may also explore auxiliary initiatives such as:- Automated evaluation pipelines designed to reduce the time from accessing a new model for pre-deployment testing to analyzing key results and disseminating them.- LLM agents and MCP tools that automate internal software engineering and research tasks, with safeguards to prevent significant failures.- Telemetry API and enhancements to our existing tools to monitor usage and improve reliability.- Upstream enhancements to the Inspect framework and ecosystem, including support for evaluating contemporary agentic scaffolds.