Senior Software Engineer - Platform Engineer

Join Klaviyo as a Software Engineer specializing in SMS International. In this role, you will be instrumental in developing and optimizing our SMS platform, enhancing user experience, and driving innovation. You will collaborate with cross-functional teams to create scalable software solutions that meet the needs of our global customer base.

At Klaviyo, we celebrate the diverse backgrounds, experiences, and perspectives that each Klaviyo (as we refer to ourselves) contributes to our workplace every day. We believe that everyone deserves an equal opportunity for success and we value the unique experiences each individual brings to our team, beyond traditional job qualifications. If you feel you are a close match for this role, we encourage you to apply. To learn more about what it's like to work at Klaviyo, visit klaviyo.com/careers to discover how we empower creators to take control of their destinies.As a Product Manager for the International SMS team, you will spearhead the expansion of Klaviyo's SMS and RCS offerings globally. With a robust international SMS framework and a newly launched RCS product, this role is pivotal in driving Klaviyo's international growth. You will collaborate closely with your engineering team, design, other Product Managers on related teams, and various stakeholders to shape our expansion strategies and ensure seamless launches across different countries, addressing phone number management, compliance requirements, and go-to-market plans. Additionally, you will stay informed about regulatory changes in these markets to ensure our strategies remain compliant and effective.SMS is a rapidly growing segment of Klaviyo's business, and this position presents a unique opportunity to play a critical role in that expansion. You will define and execute the strategy and roadmap for this product area, helping to shape the future of SMS at Klaviyo.You will report directly to the Group Product Manager for the Mobile Platform.

Why Choose Deliveroo?At Deliveroo, our mission is to revolutionize the shopping and dining experience by delivering your favorite food and products right to your doorstep. We bridge the gap between consumers, restaurants, shops, and riders, making it easier and more enjoyable to access what you love, when you want it.As a technology-driven organization, we are at the forefront of one of the fastest-growing industries globally. Although we are a compact team, our impact is significant, as we tackle some of the most compelling challenges in our sector. We prioritize speed, independence, and innovation, continually seeking fresh ideas.Joining Deliveroo offers an exceptional opportunity to build a meaningful career centered on impact—both on your personal development and our company as we scale. You can leave your mark while contributing to the positive effects we create in our marketplace and communities.About the InternshipIn your role as a Software Engineer Intern at Deliveroo, you will implement and manage technological solutions that enhance the experiences of our restaurants, riders, and customers. From designing user-friendly interfaces to developing scalable backend systems, our goal is to deliver reliable and high-performance technology that delights our users.Our 12-week internship program immerses you fully within your team, allowing you to develop, maintain, and ship products that make a real difference. You will have the chance to collaborate with your team to solve genuine problems for our customers, directly influencing our business.Candidates must possess the legal right to work in the U.K. to be eligible for this position. The internship program for 2026 will take place in person at Deliveroo's London headquarters at Cannon Bridge House.

Company OverviewDeductive AI is pioneering the development of the world's first real-time reasoning engine designed to identify and mitigate large-scale software outages. By employing advanced reasoning techniques on distributed systems, code, and statistical anomalies, we analyze vast amounts of telemetry data—including metrics, logs, traces, and events—in real-time. Our accomplished team boasts decades of experience from industry leaders such as Databricks, Facebook, Thoughtspot, Google, Splunk, and Amazon. Backed by top-tier venture capital firms, we are well-positioned for growth and innovation.Internship OverviewWe are looking for innovative interns to join our team and engage with cutting-edge technology. You will tackle fascinating challenges at the intersection of artificial intelligence, code understanding, and data analytics. Your work will involve distributed systems, the development of AI agents, and the fine-tuning and benchmarking of Large Language Models (LLMs).This is a paid, on-site internship based in Camden, London. As a Software Engineer Intern at Deductive AI, you will have the opportunity to contribute to the next generation of foundational code and data processing systems that can reason over extensive datasets, both structured and unstructured. We are committed to aligning projects with your skillset and preferences.

About Anthropic Anthropic builds AI systems with a focus on reliability, interpretability, and steerability. The company’s mission centers on making AI safe and beneficial for both individuals and society. The team includes researchers, engineers, policy experts, and business leaders working together to advance responsible AI development. Role Overview: Software Engineer, Safeguards Foundations – Internal Tooling The Safeguards team at Anthropic is responsible for detecting, reviewing, and addressing potential misuse of the company’s AI models. Within this team, the Foundations group develops the infrastructure, platforms, and internal tools that support these safeguards across the organization. This role focuses on improving internal tooling for human review. The work covers case management, labeling workflows, investigative processes, and enforcement interfaces used daily by analysts and policy specialists. Although these tools operate behind the scenes, their reliability and clarity directly affect how quickly Anthropic can spot harmful behaviors, make enforcement decisions, and provide feedback for model training. The position involves close collaboration with Trust & Safety operations, policy, and detection-engineering teams. The goal: turn complex operational needs into robust, maintainable software that supports Anthropic’s safety mission. What You Will Do Enhance and maintain internal tools for human review, including case management and enforcement interfaces Work across the stack to deliver reliable, user-friendly products for internal stakeholders Partner with operations, policy, and engineering teams to understand workflows and translate them into effective software solutions Support the organization’s ability to detect and respond to AI misuse efficiently Location London, UK

Internship Overview Wexler is seeking a Software Engineering Intern to join its London team. This is a hands-on role where interns work closely with experienced Software and Machine Learning Engineers, contributing directly to the company’s agent infrastructure and product innovation. The work impacts legal professionals who depend on Wexler’s technology every day. This internship is designed for students set to graduate in 2026 or strong second-year students from top UK universities, ideally studying Computer Science or a related field. A genuine interest in building, learning, and applied AI is important. About Wexler Wexler specializes in Legal AI, focusing on solutions tailored to the specific workflows of legal professionals. The company addresses the slow adoption of AI in the legal sector by offering targeted, precise tools rather than general-purpose platforms. Wexler’s approach has earned positive feedback for its attention to detail and commitment to supporting the needs of legal practitioners. What You Will Do Develop and improve Wexler’s agentic infrastructure. Work with the technical team on new projects that extend product capabilities. Help build user interfaces that make complex legal workflows accessible. Collaborate with AI engineers to bring LLM features into production systems. Participate in architecture discussions and learn best practices from experienced engineers. Tackle challenges such as delivering smooth user experiences, scaling performance, and upholding enterprise security standards. Technical Skills Back-end: Solid experience with Node.js, TypeScript, or Python (preferably both). Ability to write clean, testable server-side code. Databases: Familiarity with relational databases, especially PostgreSQL. Understanding of schema design and querying.

Join Elastic, the leading Search AI Company, as a Principal Software Engineer II focused on Search Internals for Lucene and Elasticsearch. In this pivotal role, you will leverage your extensive expertise to drive the evolution of our core search capabilities, ensuring we deliver an unparalleled search experience. Collaborate within a globally-distributed team of seasoned engineers to enhance our search infrastructure, including indexing and retrieval. You will define the technical vision and roadmap for Elasticsearch, working closely with product teams to shape innovative solutions that meet user needs. Your insights will continuously improve the search experience, making you a key authority in the field.

Network Support EngineerReference Number: JR254571Location: Hybrid working - remote and office near London BridgeWorking Pattern: Full Time, 37.5 hours per weekContract Type: PermanentNumber of Roles: 1Salary: £55,000 - £65,000 per annumWe are seeking a talented Network Support Engineer to join our dynamic team.In this role, you will be responsible for designing, implementing, and maintaining a robust and secure network infrastructure across both on-premise and cloud environments. Your expertise will be essential in monitoring network performance, troubleshooting issues, and managing critical network components such as routers, firewalls, and load balancers. You will work collaboratively with internal teams and external vendors, providing advanced support while driving continuous improvements within the network.This is an exceptional opportunity for a skilled Network Support Engineer eager to grow their career with an industry leader.A detailed job description can be viewed here. If the link does not work for you, please copy and paste the following URL into your web browser: https://tinyurl.com/epu3atr3.

Kaplan International is hiring a Director of Application Engineering and Architecture based in London, with a hybrid work arrangement (home and office near London Bridge). This is a full-time, permanent position working 37.5 hours per week. Role overview This senior leadership role reports to the VP of Information Technology. The Director will guide the design, development, and delivery of technology solutions across the company. The position oversees teams responsible for building and supporting applications, ensuring platforms are scalable and reliable while meeting business goals. Responsibilities include setting engineering standards, defining architectural guidelines, and making decisions that support both current needs and future growth. The Director will shape how technology is delivered and maintained throughout the organization. Key details Reference Number: JR255016 Location: Hybrid (home and London Bridge office) Working pattern: Full time, 37.5 hours per week Contract type: Permanent Number of roles: 1 Salary: Competitive More information For the full job description, view this document. If the link does not work, copy and paste this URL into your browser: https://tinyurl.com/y7ud595b.

The Position: We are in search of motivated and passionate Graduate Software Engineers to join our dynamic Engineering team in London. The ideal candidates will collaborate within cross-functional teams alongside product managers and designers, working closely with various departments to produce quality code that addresses genuine challenges for both internal and external stakeholders. This role offers the opportunity to take ownership of the solutions your team develops, ensuring excellence in all released products while contributing to a high-performing international development team. If you’re eager to tackle real-world problems through coding and thrive in a results-oriented environment, this could be the perfect opportunity for you. Key Responsibilities: Craft Solutions: Identify and define optimal technical solutions to business challenges, contributing to an architectural vision aimed at establishing us as the world’s leading research platform. Deliver Functional Code: Engage with React for frontend development and Kotlin microservices with PostgreSQL for backend solutions, while also maintaining legacy services in Ruby on Rails. We continuously evaluate new technologies that might enhance our stack. Deploy and Improve: Release updates frequently to our users, utilizing CIrcleCI and Spinnaker for CI/CD processes and rapidly gather user feedback to inform subsequent iterations. Enhance Your Skills: Accelerate your learning through hands-on experience in building cutting-edge technology with seasoned professionals in a performance-driven setting. Engineers have access to our Learning and Development budget to quickly acquire specific technical skills. Monitor and Troubleshoot: Vigilantly oversee our services to identify errors proactively, diagnose root causes, and implement fixes efficiently. Your Profile: You are currently pursuing a degree in Computer Science or a related field. Technical Proficiency: Familiarity with Kotlin, Java, Python, or React is required. Demonstrated Achievements: You have a clear record of accomplishments in your studies or previous roles.

Position Overview:We are in search of a skilled and enthusiastic Software Developer to become an integral part of our expanding team. In this pivotal role, you will be instrumental in the design, development, and maintenance of Squarepoint's internal frameworks, services, and platforms that drive our business operations. This is a fantastic opportunity to work with advanced technologies, directly influencing the efficiency and productivity of both our investment and technology teams at Squarepoint.Design, develop, and maintain high-quality, scalable, and high-performance software solutions.Contribute to the creation of company-wide productivity tools, frameworks, and platforms that enhance operations across the organization.Collaborate with fellow developers and stakeholders to collect requirements, design solutions, and implement features.Write clean, well-documented, and testable Python code.Engage in code reviews and help elevate code quality and development practices.Diagnose and resolve technical issues promptly and effectively.Stay informed about the latest advancements in Python technologies and industry best practices.

About xAIAt xAI, we are dedicated to developing AI systems that possess a profound understanding of the universe, ultimately assisting humanity in its quest for knowledge. Our compact team is driven, motivated, and committed to engineering excellence, making our organization ideal for individuals who relish challenges and foster curiosity. We pride ourselves on a flat organizational structure where every employee plays a vital role in advancing our mission. We recognize initiative and excellence in our leadership approach, and emphasize the importance of work ethic and prioritization skills. Strong communication abilities are crucial, enabling team members to share knowledge clearly and effectively.About the RoleThis newly established civilian team is focused on engineering and deploying xAI's AI capabilities (models, APIs, tools, and integrations) for international government agencies, regional and local administrations, and public sector workflows globally. We are building the bridge to responsible, impactful AI adoption. Team members will have opportunities for travel and international assignments, primarily in the Americas, Asia, and the Middle East. You will collaborate closely with product, research, infrastructure, and legal/governance teams to ensure that Grok and future models serve global civilian missions effectively while maintaining safety, transparency, and ethical standards.ResponsibilitiesDesign, build, and optimize integrations between xAI's frontier models (e.g., Grok family) and international government systems, platforms, and data environments.Develop secure, scalable solutions for applications such as policy analysis, educational technology, scientific research support, public health modeling, regulatory workflows, and citizen-facing services across diverse global contexts.Collaborate on custom SDKs, APIs, developer tools, and documentation tailored for international government and enterprise developers.Engage with international agency stakeholders to understand requirements, prototype solutions, and iterate based on feedback.

Join Runna as a Senior Software Engineer II, where you'll play a pivotal role in enhancing our software solutions. You will collaborate with cross-functional teams to design, develop, and implement robust applications that meet our customers' needs. Your expertise will help us push the boundaries of technology, ensuring our products remain at the forefront of the industry.

Why Join Faculty?Founded in 2014, Faculty believes that artificial intelligence (AI) is poised to be one of the most transformative technologies of our era. Over the years, we have collaborated with more than 350 global clients, helping them enhance their performance through human-centered AI solutions. Discover our impactful projects here.At Faculty, we prioritize genuine innovation over fleeting trends. We focus on developing and implementing responsible AI that truly makes a difference. Our clients range across various sectors, including government, finance, retail, energy, life sciences, and defense, and we possess an unmatched depth of technical, product, and delivery expertise.As our reputation grows, we continuously seek talented individuals who share our intellectual curiosity and are eager to leave a positive legacy through technology.AI is a groundbreaking technology; join us to explore its most powerful applications and help bring them to life.About the TeamWithin our Professional and Financial Services Business unit, we leverage over a decade of Applied AI experience to assist our clients in navigating a fast-evolving landscape. We create and integrate AI solutions that enhance efficiency, improve customer experience, and uncover commercial opportunities in uncertain markets. In a highly regulated industry, we see immense potential for meaningful innovation and are proud to set the standard for combining technical excellence with secure deployment.About the RoleAs a Lead Software Engineer, you will drive the technical direction and execution of complex, innovative AI projects. Acting as a technical authority, you will apply your expertise across various initiatives, from AI strategy formulation to client-side implementations, ensuring that architectural decisions are both robust and reliable. This role requires a blend of profound technical knowledge and strong leadership capabilities, emphasizing innovation, team development, and the creation of reusable solutions across the organization. If you are ready to oversee high-stakes projects and deliver impactful, innovative results, this is your opportunity to shape our future.What You'll Be DoingLeading the technical direction and delivery of sophisticated AI projects.Applying your technical expertise to various projects, ensuring sound architectural decisions.Driving innovation while fostering team growth and collaboration.Building reusable solutions that can be leveraged across the organization.

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 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.

About the Role Samsara is hiring a Software Engineering Manager based in London (UK2) or remotely within the UK. This position leads a team of engineers focused on building software that helps businesses work smarter and more efficiently. What You Will Do Guide and support a team of engineers as they design, build, and deliver software products Shape product development by collaborating with cross-functional partners Encourage a team culture that values creativity, technical growth, and collaboration Work Location London, UK2 office Remote within the UK

We are seeking a Principal Software Engineer specialized in engineering applications to join our dynamic team at physicsx. In this role, you will lead the design and development of innovative software solutions that empower our engineering teams to achieve exceptional results. Your expertise will drive the implementation of cutting-edge technologies and methodologies, ensuring the highest standards of performance and reliability.As a Principal Software Engineer, you will collaborate closely with cross-functional teams, mentor junior engineers, and contribute to the overall technical strategy of our organization. You will have the opportunity to work on challenging projects that have a significant impact on our business and clients.

Role overview Based in London, the Senior Software Engineering Manager for Quality Engineering at Sony Interactive Entertainment Global leads a talented group of engineers. The position centers on defining and executing the strategy for software quality and performance across projects. Main responsibilities Shape the strategic direction for the quality engineering team Mentor and guide engineers, supporting their professional development Establish and maintain effective software testing practices Encourage ongoing improvement within the team Collaborate with cross-functional partners to ensure quality standards are met throughout the software development lifecycle Collaboration and impact This leadership role bridges engineering and quality, making sure software products meet rigorous standards from initial planning through release. Regular interaction with teams across Sony Interactive Entertainment Global helps to maintain and raise quality expectations company-wide.