Senior Software Engineer - London

About H: H exists to push the boundaries of superintelligence with agentic AI. By automating complex, multi-step tasks typically performed by humans, AI agents will help unlock full human potential. H is hiring the world’s best AI talent, seeking those who are dedicated as much to building safely and responsibly as to advancing disruptive agentic capabilities. We promote a mindset of openness, learning, and collaboration, where everyone has something to contribute. About the Team: The Product Engineering team is responsible for developing H’s Enterprise Platform, providing all the tools and services to support critical operational use-cases for our customers. Our platform includes key services, from executing computer-use agents at scale, to orchestrating complex workflows and providing a complete observability, troubleshooting and evals suite of tools. Our Product Engineering team is at the heart of our company’s development, bridging the gap between AI research and real-world impact, and works closely with all parts of the organization. Key Responsibilities: - Define and lead technical architecture, design, and long-term engineering roadmap. - Develop and maintain complex, high-performance, and scalable systems. - Mentor and guide engineers across multiple teams, fostering technical excellence. - Conduct thorough code and design reviews, ensuring quality and security best practices. - Collaborate with Research, Product, and other stakeholders to deliver impactful solutions. - Drive improvements in system reliability, scalability, and observability. - Establish and enforce engineering standards, tooling, and processes. - Champion technical innovation and proactively address technical debt. REQUIREMENTS: - Technical skills: - Previous demonstrable role(s) as Senior Software Engineer with relevant set of responsibilities and achievements - Strong 5+ years of experience in backend development (Python & Golang preferred) - In-depth experience with distributed systems or cloud computing, preferably in AWS - Experience building and shipping end to end solutions - Experience building APIs (REST and/or GraphQL) and integrating with external services - Expertise in relational and non-relational databases - Experience working with message queueing technologies (SQS/RabbitMQ/Kafka/etc.) - Solid understanding of coding standards, architectural patterns and test frameworks - Expertise in instrumentation, observability and monitoring - Soft skills: - Mentorship & Influence - You inspire and elevate engineers across teams - you are a true force multiplier. - Cross-Functional Communication - You communicate effectively with engineers and business leaders, switching between technical and business contexts. - Technical Leadership – You are able to guide teams through complex technical decisions, balancing short-term delivery with long-term architectural health. Location: - Paris or London. - This role is hybrid, and you are expected to be in the office 3 days a week on average. - Please expect some travel between offices on a reasonable cadence (e.g., every 4-6 weeks). What We Offer: - Join the exciting journey of shaping the future of AI, and be part of the early days of one of the hottest AI startups. - Collaborate with a fun, dynamic, and multicultural team, working alongside world-class AI talent in a highly collaborative environment. - Enjoy a competitive salary. - Unlock opportunities for professional growth, continuous learning, and career development. If you want to change the status quo in AI, join us.