Senior Lead - Staff Software Engineer

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 fro…

C/C++ Software Engineer (Video)Location: LondonAbout UsAt New Route Recruitment Limited, we are proud to present our state-of-the-art video platform designed for live, social, and mobile environments. Our cloud-based technology alleviates the conventional challenges associated with professional video production and distribution.We collaborate with some of the world's leading broadcasters and rights holders, including renowned names like Sky Sports, BT Sport, Eurosport, ITV, Turner, The Premier League, LaLiga, The FA, Buzzfeed, AELTC Wimbledon, and GOAL.com. Our platform seamlessly integrates with major social media channels such as Facebook, Instagram, Periscope, Twitter, and YouTube, and we are a recognized global partner for Facebook Live.Leveraging Amazon Web Services as our primary hosting provider, our platform is designed for scalability and high availability to serve a global clientele. This cloud-based infrastructure empowers our engineers with agility, enabling them to explore innovative solutions while ensuring reliability and rapid development cycles.We believe in the potential of nurturing bright graduates and junior engineers, which we view as vital to our growth. From day one, you will be paired with a mentor who will assist you with technical inquiries and guide your career path by helping you identify your focus area within our platform (video, data, front-end, architecture, streaming, etc.) while providing regular performance evaluations.Your well-being and commitment to our team are paramount. We encourage pushing the boundaries with cutting-edge technologies and provide you with significant responsibilities from day one—overseeing the entire product lifecycle: from design and architecture to deployment, support, and monitoring in production. This approach ensures that you feel engaged, challenged, and impactful in your role.Our commitment to creating a supportive environment has contributed to the long-term retention of our talent. Many of our current senior engineers, including our Product Owner and Lead Software Architect, started as graduate engineers and have evolved into key leadership roles within the organization.We value social interactions and fun, offering various activities to foster team spirit.If you are driven by technology and eager to make a difference, we want you on our team!As a C/C++ Software Engineer, you will play a crucial role in designing, building, and supporting the platform’s Media Engine, which facilitates live and on-demand encoding, including applying exciting video effects.

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 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.

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.

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.

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.

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.

About AirwallexAirwallex stands as the only integrated payments and financial platform tailored for global enterprises. Our unique blend of proprietary infrastructure and innovative software empowers over 200,000 businesses globally, including industry leaders like Brex, Rippling, Navan, Qantas, and SHEIN, offering fully integrated solutions for managing business accounts, payments, spend management, treasury, and embedded finance on a worldwide scale.Established in Melbourne, our team comprises more than 2,000 of the brightest minds in the tech industry across 26 global offices. Valued at US$8 billion and supported by world-renowned investors such as T. Rowe Price, Visa, Mastercard, Robinhood Ventures, Sequoia, Salesforce Ventures, DST Global, and Lone Pine Capital, Airwallex is at the forefront of constructing the global financial and payments platform of the future. If you are prepared to engage in the most ambitious work of your career, we invite you to join us.

Our VisionAt Omnea, we are passionately transforming the enterprise landscape, specifically tackling the complexities of procurement. Our goal is to eliminate the lengthy processes that often involve over 50 emails and the engagement of multiple departments such as Finance, Legal, Security, and IT just to secure a simple purchase approval.With a significant investment of $75M from Khosla Ventures, Insight Partners, and Accel, we are set on a mission to revolutionize this space. Our AI-driven platform seamlessly integrates all stakeholders, automating approvals and renewals, managing supplier risks in real-time, and providing complete visibility into spending.The procurement market is valued at over $7B, and our remarkable progress demonstrates the potential: we have achieved a tenfold increase in ARR to double-digit millions within just 18 months, working with esteemed global clients like Spotify, MongoDB, Monzo, and Albertsons. We are proud to be recognized as the 4th fastest growing startup in Europe.Our team boasts experience from scaling Tessian (a cybersecurity tech firm supported by Sequoia, Balderton, and Accel, acquired post-Series C), including former founders and operators who have led unicorn companies and developed top-tier products. You will collaborate with distinguished leaders such as Ben, Abs, Sabrina, and Rebe.What We SeekWe are on the lookout for an outstanding, product-oriented Team Leader - Staff Software Engineer (L4) to enhance our engineering team and navigate Omnea through this exciting growth phase. In the upcoming year, we aim to double our team size, expand our enterprise client base from approximately 100 to over 200, and triple our revenue. This Staff-level position offers a significant opportunity for domain-level influence, combining senior technical leadership with team management duties. You will guide a team, mentor engineers, and shape architectural and product decisions across a broader domain while remaining actively engaged in critical areas.You will be joining us at a critical juncture as we have just secured a $50M funding round to further our mission...

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 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.

About WatershedWatershed is a premier enterprise sustainability platform utilized by leading organizations such as Airbnb, Carlyle Group, FedEx, Visa, and Dr. Martens. Our platform enables companies to effectively manage climate and ESG data, generate audit-ready metrics for both voluntary and regulatory reporting including CSRD, and facilitate substantial decarbonization efforts. We seek passionate individuals who are enthusiastic about product development, eager to contribute to a mission-driven startup, and willing to collaborate in shaping a vibrant team culture.With offices in San Francisco, New York, Denver, London, Paris, Berlin, Sydney, Mexico City, and a robust remote workforce across the US and Europe, we invite you to explore the opportunity to join our dynamic team!The RoleWe are on the lookout for a talented software engineer with a specialization in AI to become a key member of our sustainability AI reporting team. In this technical leadership role, you will assist in the creation of a cutting-edge AI tool that empowers companies to manage and report their sustainability progress. You will harness LLMs, embeddings, and various AI technologies to deliver innovative features to our customers while establishing the technical groundwork for AI at Watershed.This position requires being based in our London HQ four days a week.Your Responsibilities:Prototype, develop, and refine new product features for Watershed, empowering our customers with advanced AI tools for data extraction and report generation.Productionize and launch core technologies necessary for AI functionalities, leveraging extensive operational sustainability data.Engage with product and other AI engineering teams to define product and technical strategy.Stay informed about advancements and state-of-the-art developments in AI to assess relevance for Watershed.Write efficient, high-quality, tested, and maintainable code across our technical stack.Ideal Candidates Will Have:A minimum of 2 years of experience in building AI-powered products and 5+ years in software engineering.Proven experience in developing products utilizing LLMs, embeddings, and other machine learning technologies.Comprehensive experience with the lifecycle of building, deploying, and monitoring products that leverage LLMs, embeddings, or other machine learning technologies.

Join Our Mission to Empower UK Small Businesses As a pivotal part of the economy, small businesses deserve the best support to thrive. At Funding Circle, we’ve engineered a revolutionary platform that leverages innovative data solutions to provide fast funding—delivered in minutes, not weeks.We embody the dynamic spirit of a fintech start-up combined with the reliability of a public company. This unique blend empowers our team, known as Circlers, to take initiative and make significant impacts in the financial landscape.Our high-performing team thrives on collaboration, support, and mutual respect. We believe that together, we can accelerate progress and enhance our overall performance.Your Contribution Matters: Last year, our platform enabled businesses to generate a remarkable £7.2bn for the UK economy Join us in making a difference![Explore Our Impact Report] | [Check Our Trustpilot Ratings]The Role London (Hybrid) | 2 days in the office | Competitive Salary + BenefitsWe seek a passionate and seasoned Staff Engineer to lead our Product Engineering team, focusing on our cutting-edge Loans Engineering Group. You will provide essential technical leadership for the platform that powers our industry-leading term loan products.As one of our senior technology leaders, you will elevate our standards and drive us towards remarkable achievements.Collaborate closely with Product leadership to align business objectives with technical strategies, creating a clear roadmap for system and data architecture.Exhibit exceptional documentation skills by producing comprehensive technical designs and standards.Uphold high standards, foster continuous improvement, and guide others towards excellence.Mentor Lead Engineers, providing constructive feedback and establishing decision-making frameworks that support their growth.

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.

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 MentisAt Mentis, we are dedicated to creating reliable AI solutions for critical sectors such as finance, healthcare, and legal. Our team specializes in developing meticulously curated evaluation datasets and reinforcement learning environments. We empower AI labs and startups by providing them with expertly crafted training data, calibrated assessment rubrics, and rigorous task environments to push the boundaries of AI capabilities in regulated industries.As a tight-knit team based in London, we pride ourselves on our agility and commitment to excellence. Every member plays a vital role in our mission, and we value initiative and ownership in our collaborative work culture. If you are passionate about shaping the future of frontier AI applications, we want to hear from you.About the RoleAs a Software Engineer and Member of Technical Staff, you will be instrumental in building and scaling the platform that drives Mentis' operations. You will develop essential annotation tools, workflow systems, quality control pipelines, and internal infrastructure fundamental to every dataset and environment we deliver.Your daily tasks will include designing expert task creation workflows, creating task assignment and review interfaces, developing data pipelines to convert expert outputs into structured training sets, and integrating LLM-powered tools into our product. Your role will vary from product engineering to infrastructure development, with a consistent focus on producing high-quality evaluation data at scale.You will take ownership of the platform's development, making key decisions on what features to build, how to implement them, and establishing the standards for our growth.What You'll DoDevelop and manage the core data annotation and workflow platform from start to finish, overseeing task assignment, expert interfaces, quality control, and dataset delivery.Design systems that facilitate expert onboarding, task routing, review workflows, and scalable quality assurance processes.Enhance AI-integrated pipelines across the platform, including LLM-assisted annotation, automated checks, and model-in-the-loop workflows.Collaborate directly with founders and domain experts to streamline bespoke processes into effective, scalable software solutions.Make informed product and engineering decisions in a dynamic environment, prioritizing and shipping features without waiting for perfect specifications.Contribute to defining our team’s development practices, including tooling choices, engineering standards, and product strategy.Who We're Looking ForWe seek a proactive individual who thrives in fast-paced environments and embraces ambiguity. If you are excited about the opportunity to influence how AI learns and operates in real-world settings, we welcome your application.