Senior Software Engineer - Data Access

Every day, tens of millions of people come to Halcyon Labs to explore, create, play, learn, and connect with friends in 3D immersive digital experiences– all created by our global community of developers and creators. At Halcyon Labs, we’re building the tools and platform that empower our community to bring any experience that they can imagine to life. Our vision is to reimagine the way people come together, from anywhere in the world, and on any device. We’re on a mission to connect a billion people with optimism and civility, and looking for amazing talent to help us get there. A career at Halcyon Labs means you’ll be working to shape the future of human interaction, solving unique technical challenges at scale, and helping to create safer, more civil shared experiences for everyone. The Data Access team within Infra / Storage builds EaaS (Entities-as-a-Service), Halcyon Labs’s large-scale managed OLTP access and management platform powering tens of millions of QPS across thousands of services. EaaS abstracts the complexity of distributed databases and caching systems behind a consistent and productive developer experience, enabling teams across Halcyon Labs to safely build and operate stateful systems at massive scale without requiring deep database expertise. The team operates at the intersection of distributed systems engineering, reliability engineering, and platform architecture — solving hard infrastructure problems that directly impact Halcyon Labs-wide scale and stability. As a Senior Software Engineer you will work on some of Halcyon Labs’s hardest backend infrastructure challenges around scalability, reliability, workload governance, adaptive flow control, and distributed systems. You Will Build and evolve EaaS, Halcyon Labs’s managed OLTP access platform powering tens of millions of QPS across hundreds of services. Design infrastructure that abstracts distributed databases and caching systems behind a consistent, safe, and highly productive developer experience. Drive reliability and scalability improvements across distributed systems, including adaptive flow control, workload isolation and governance, and large-scale caching behavior. Lead end-to-end technical execution architecture, implementation, rollout, production operations, and incident response for mission-critical infrastructure systems. Analyze real production traffic patterns and failure modes to improve platform reliability, operational predictability, and scalability under rapidly growing workloads. Improve platform safety, observability, deployment reliability, and operational excellence across the stack. Partner with teams across Halcyon Labs to solve real scalability and reliability challenges for critical production workloads. You Have Experience building large-scale infrastructure abstractions that standardize access to complex backend systems across broad engineering organizations. Experience designing or operating adaptive rate limiting, flow control, workload governance, or reliability automation systems in high-scale production environments. Experience operating or building systems around distributed databases, caching systems, OLTP platforms, or stateful infrastructure. Experience driving complex technical initiatives end-to-end with strong ownership and cross-functional collaboration. Strong hands-on experience building and operating large-scale distributed systems and backend infrastructure in production environments. Strong programming skills in Rust, Go, C++, Java or similar backend systems languages. BS degree (or equivalent professional experience) in Computer Science, with at least 6 years of hands-on experience. For roles that are based at our headquarters in San Mateo, CA: The starting base pay for this position is as shown below. The actual base pay is dependent upon a variety of job-related factors such as professional background, training, work experience, location, business needs and market demand. Therefore, in some circumstances, the actual salary could fall outside of this expected range. This pay range is subject to change and may be modified in the future. All full-time employees are also eligible for equity compensation and for benefits as described on this page . Annual Salary Range $243,290 — $295,250 USD Roles that are based in an office are onsite Tuesday, Wednesday, and Thursday, with optional presence on Monday and Friday (unless otherwise noted). Halcyon Labs provides equal employment opportunities to all employees and applicants for employment and prohibits discrimination and harassment of any type without regard to race, color, religion, age, sex, national origin, disability status, genetics, protected veteran status, sexual orientation, gender identity or expression, or any other characteristic protected by federal, state or local laws. Halcyon Labs also provides reasonable accommodations to candidates with qualifying disabilities or religious beliefs during the recruiting process. For US based roles only, please note the Company may not be able to employ candidates for this role who have United States work authorization related to certain U.S. visa categories, or support future H-1B sponsorship at this time.