Senior Software Engineer - Platform Runtime

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.

Role overview As a Staff Engineer on the Data Platform team at yuno in London, the focus is on designing and developing scalable data solutions. These systems help internal teams operate more efficiently and contribute to product improvements across the company. This position involves hands-on work with technical architecture, providing the chance to influence how data systems are built and maintained. Projects in this role are closely tied to business goals, with a direct impact on yuno’s progress. Key responsibilities Build and maintain scalable data platforms to support internal stakeholders Contribute to the design and evolution of technical architecture Work on projects that drive product and business growth Location This role is based in London.

About Swap Swap builds the infrastructure for modern agentic commerce. The platform connects backend operations with a new kind of storefront, using AI to help brands manage and grow their business globally. Swap’s platform brings together cross-border operations, tax management, returns, demand forecasting, and a storefront powered by agentic technology. Merchants get real-time data, transparency, and tools to act quickly and decisively. The company values clarity, creativity, and shared ownership as it rethinks how global commerce works. Role Overview: Staff Software Engineer in Test – QA Platform Lead Swap is hiring a Staff Software Engineer in Test to lead the development of its internal QA Platform. This role focuses on building the tools and infrastructure that help engineering teams ship reliable software, faster. The QA Platform Lead will design, build, and maintain the internal platform, including frameworks, automation pipelines, and AI-assisted workflows, that Swap engineers rely on every day. The impact of this work will be measured by how widely the platform is adopted, the developer experience, and the speed at which teams can deliver quality software. Collaboration is key. The role works closely with the current SDET, who created the existing end-to-end testing framework. Together, you’ll expand on this foundation and shape a broader platform vision. The QA Platform Lead will set strategy, manage the roadmap, and make decisions about priorities and architecture. Main Responsibilities QA Platform Strategy and Roadmap Define the vision, strategy, and roadmap for the QA Platform, setting priorities that maximize impact. Make architectural and tooling decisions that influence quality practices across Swap’s engineering teams. Track adoption, usage, and developer satisfaction to ensure the platform is used and valued, not just built. Develop Reusable Quality Tools and Infrastructure Design and implement reusable tools, frameworks, and self-service quality infrastructure to help engineering teams deliver with confidence and less friction. Location This role is based in London.

Role overview Wise is looking for a Staff Software Engineer to join the Regional Payments Platform team in London. The team builds and enhances payment systems that reach millions of users worldwide. This position centers on developing technology that supports reliable and efficient payment experiences at scale. What you will do Collaborate with colleagues from various disciplines to design and implement scalable payment solutions. Offer technical leadership and insight on complex projects that affect users globally. Influence the architecture and future direction of Wise’s regional payments platform.

Join Hudson River Trading (HRT), a leading global algorithmic trading firm, where innovation meets high-performance computing. Our research cluster is the cornerstone of our trading success, providing the robust environment where cutting-edge trading strategies are conceived and executed. At HRT, we leverage a state-of-the-art research ecosystem featuring advanced CPU and GPU computing, expansive storage solutions, and high-speed networking technologies. Our engineering team meticulously handles the software stack, optimizing everything from user-level APIs to low-level caching mechanisms. We tackle a diverse range of challenges—from theoretical resource scheduling to the practical optimization of trading program runtime performance. As a Distributed Compute Engineer, you will play a vital role in shaping the user experience for our research environment, developing and refining technical solutions that enhance research efficiency and accessibility. Collaborating daily with our talented quantitative traders and software engineers, you'll contribute to a dynamic environment that fosters innovation and excellence.

Join Isomorphic Labs, where we are harnessing cutting-edge AI to drive revolutionary scientific discoveries, accelerate breakthroughs, and develop transformative medicines, with the ultimate goal of tackling all diseases.We envision a future powered by the remarkable capabilities of machine learning—one where drug discovery is not only improved but revolutionized.Be a vital part of our dynamic interdisciplinary team, dedicated to pioneering innovations and playing a significant role in our ambitious mission, all while thriving within a culture that inspires collaboration and creativity.The future we aspire to is being shaped today, starting with our company culture and each one of us.About Isomorphic LabsFounded in 2021, Isomorphic Labs is committed to enhancing human health through advanced AI technologies, building on the Nobel-winning AlphaFold system. Our diverse team of drug discovery professionals and machine learning experts has developed powerful predictive and generative AI models that expedite scientific discovery at an unprecedented pace.Our name embodies our belief in the intrinsic symmetry between biology and information science. By leveraging AI’s robust capabilities, we model intricate biological phenomena to design innovative molecules, predict drug performance, and create groundbreaking treatments for some of the world’s most pressing health challenges.We have established a leading drug design engine featuring AI models adept at working across various therapeutic areas and drug modalities. Our commitment to continuous innovation in model architecture and the development of advanced capabilities propels the future of rational drug design.With each breakthrough, we are inching closer to the realization of digital biology and our ambitious mission to ultimately conquer all diseases with the power of AI.

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.

Join Our Team as a Staff Software EngineerAt Deliveroo, we are dedicated to revolutionizing the way people shop and dine. Our commitment to impact, innovation, and growth is at the core of everything we do. Our engineering teams are tasked with addressing intricate technical challenges within a global, three-sided marketplace, developing and scaling systems that cater to millions of customers, riders, and partners daily.From real-time logistics to robust infrastructure and marketplace optimization, we design, build, and operate the technology that fuels Deliveroo's expansive growth.We are seeking a Staff Software Engineer to become a key member of our London, UK - Hybrid (3 days in the office) team. In this pivotal role, you will help us craft technical solutions for essential business challenges and steer the technical direction for complex, high-scale systems.Discover our Engineering team — learn about our motivations, work culture, and what you can expect when you join us.

Join our dynamic team as a Staff Software Engineer at CyberArk, where you will be instrumental in developing cutting-edge security solutions. You will collaborate with a talented group of engineers to design, implement, and maintain software systems that protect against evolving cyber threats. Your expertise will contribute to innovative projects that shape the future of enterprise security.

Join unlikelyAI as a Staff Software Engineer and be at the forefront of developing cutting-edge artificial intelligence solutions. In this pivotal role, you will collaborate with a talented team to design, implement, and optimize software systems that push the boundaries of technology.As a key member of our engineering team, you'll have the opportunity to influence the architecture of our products and mentor junior engineers. We are looking for innovative thinkers who thrive in a fast-paced environment and are passionate about building scalable and efficient software.

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.

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 Plaid as a Staff Software Engineer and be a vital part of our team in London. We are looking for innovative engineers who are passionate about building the infrastructure that powers the future of fintech. You will work alongside talented professionals, contributing to an exciting array of projects that will challenge your skills and help you grow.

About Checkout.com Checkout.com helps businesses succeed in the digital economy. Leading companies such as eBay, ASOS, Klarna, Uber Eats, and Sony rely on our platform to process seamless online payments. Our global network supports billions of transactions each year, focusing on reliability and ease of use. Headquartered in London, Checkout.com operates from 19 offices across six continents. The company values high performance and continuous improvement. Working here means contributing to the future of fintech alongside teams striving for excellence. Role Overview: Staff Software Engineer - Streaming The Data and AI Platform Team is looking for a Staff Software Engineer to help build a scalable platform for AI-driven streaming and batch data applications. This platform will improve how data is shared and used across Checkout.com, supporting business growth and performance. The team’s mission is to make it easier for internal teams to collect, store, process, and use data for impactful AI projects and data products. The focus is on reducing technical overhead so engineers can spend more time solving business challenges, not managing infrastructure or deployments. Current work lays the foundation for systems that will scale to support hundreds of teams and handle petabytes of data. Main Responsibilities Design and develop a highly available event streaming platform using technologies like Kafka and Flink. Offer technical leadership and mentorship, providing strategic direction and building strong relationships with engineers and managers across the organization. Work with cross-functional teams to deliver data solutions that support business goals. Location This role is based in London.

Join Carta, a leading financial technology company, as a Staff Software Engineer. In this role, you will contribute to the development of innovative software solutions that empower companies to manage their equity and ownership structures more effectively. You will collaborate with cross-functional teams, leveraging the latest technologies to deliver robust and scalable applications.

Join our innovative team at Astronomer as a Staff Software Engineer specializing in Data. In this role, you will help shape the future of data engineering solutions that empower organizations to harness the full potential of their data. You will work collaboratively with cross-functional teams to design, develop, and optimize data pipelines and infrastructure, ensuring high performance and reliability.

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 Ki Insurance, a pioneer in the insurance industry, as we redefine a 335-year-old market with cutting-edge technology. Our innovative platform, developed in collaboration with Google and UCL, leverages algorithms and machine learning to deliver lightning-fast quotes to insurance brokers, transforming the industry standard.As the largest global algorithmic insurance carrier and the fastest-growing syndicate in the Lloyd's of London market, Ki Insurance has achieved extraordinary milestones, including generating $100 million in profit within just three years.Our diverse teams thrive in an agile, cross-functional environment, where collaboration and creativity lead to exceptional customer experiences. We are on the lookout for brilliant minds to join us on our mission to challenge conventions and explore new possibilities.As a Staff Software Engineer, you will play a pivotal role in our engineering team, providing technical leadership to both delivery squads and the broader engineering organization. You will champion engineering excellence and uphold high standards of quality, fostering a culture of continuous improvement. Your hands-on approach will enable you to design and deliver impactful software solutions while guiding your colleagues to achieve collective goals.Are you ready to make your mark? Develop robust and scalable software for critical web-based applications.Design, implement, test, document, and maintain APIs and integrations.Create new features within our core Kotlin-based services, collaborating with multi-disciplinary teams.Ensure quality control through techniques such as automated testing, code review, and pair programming.Work closely with the Product team to translate user requirements into effective technical solutions.Document technical designs and analyses thoroughly.Evaluate existing system architecture, identifying areas for enhancement and growth.Prototype and explore innovative ideas and technologies swiftly.Promote a culture of continuous improvement, leading by example and positively influencing our practices.

Role Overview Utility Warehouse is looking for a Staff Software Engineer to focus on Energy. This role shapes the design and implementation of software that supports our energy services. The position calls for both technical leadership and hands-on development. What You Will Do Design and build software solutions for energy products and services Guide engineers to deliver reliable, maintainable code Promote sustainability and efficiency in technical decisions Impact This position supports Utility Warehouse’s goal of improving the energy sector with technology. Staff Engineers in this area influence both the technical direction and the quality of delivery across teams.