Sekai is building the TikTok for mini apps — an AI-driven consumer platform where people create, remix, share, and play interactive content instantly. We are a Series A company backed by Khosla, a16z and Mayfield, with $30M raised to date. We are remote-first across all positions and are looking for ambitious, AI-native builders who want to help shape the next generation of consumer social products.
🏢 About Sekai
Sekai is an AI-powered consumer platform where users can create, remix, and play interactive content. We build mobile-first products at the intersection of AI, consumer social, and interactive entertainment. We are a Series A company backed by top VCs including a16z, a+, Mayfield, and Khosla, and have raised a total of $30m.
🎯 The Role
We're looking for a Backend & Cloud Infrastructure Engineer to help build and scale the systems behind Sekai. In this role, you'll work across backend development and cloud infrastructure, building high-performance APIs, supporting AI/LLM workloads, and ensuring our platform is scalable, reliable, and efficient. You'll have end-to-end ownership, from designing core backend services to optimizing AWS infrastructure and improving overall system performance. It's a great opportunity for someone who enjoys both building products and solving complex infrastructure challenges in a fast-moving startup environment.
✅ Key Responsibilities
Own the architecture, development, and evolution of core backend services. Write high-quality code in Python / Go, and lead design reviews and code reviews.
Design and build high-performance, highly available RESTful / gRPC APIs that serve high-traffic consumer features and AI / LLM workloads.
Design and tune async task processing and message queues (Kafka, Celery, SQS, etc.) for throughput and data consistency.
Plan, build, and govern our AWS infrastructure (ECS / Lambda / RDS / S3 / CloudFront / VPC, etc.), and drive Infrastructure as Code with Terraform or similar tools.
Build and improve monitoring, logging, and alerting (Datadog, CloudWatch, Sentry). Keep alerts actionable and production stable.
Lead incident troubleshooting, on-call response, and postmortems. Keep improving capacity planning, autoscaling, and disaster recovery.
Own cloud cost and security: remove idle resources, enforce least-privilege IAM, and manage multiple accounts and internal network access.
Turn shared business logic into reusable services, middleware, and internal tools, and improve CI/CD so the team ships faster and more reliably.
📌 Required Qualifications
5+ years of backend development experience, including at least 2 years in cloud or infrastructure work.
Strong proficiency in Python or Go, with hands-on experience building large projects on frameworks such as FastAPI, Django, or Gin.
Solid knowledge of core AWS services, with production experience in architecture, operations, and cost optimization.
Experience with Docker and ECS / Kubernetes, and with IaC tools such as Terraform.
Strong MySQL / PostgreSQL schema design and performance tuning skills. Familiar with Redis, Kafka, Nginx, and other common middleware.
Strong production debugging skills, with on-call and postmortem experience. Good communicator who can own a project end to end, from design to launch.
⭐ Desirable Experience
Backend experience with AI / LLM applications, such as model integration, agent systems, or managing LLM cost and reliability.
