Senior Backend & Cloud Infrastructure Engineer

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.

Here are Sekai’s download links:

Android: https://play.google.com/store/apps/details?id=chat.sekai.app&hl=en_US

IOS: https://apps.apple.com/us/app/sekai-create-remix-play/id6504506653

About 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.

Responsibilities

• Backend Development
• 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.
• Cloud Platform & Reliability
• 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.
• Infrastructure & Platform
• Turn shared business logic into reusable services, middleware, and internal tools, and improve CI/CD so the team ships faster and more reliably.

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.

Preferred Qualifications

• Backend experience with AI / LLM applications, such as model integration, agent systems, or managing LLM cost and reliability.
• Experience supporting large-scale, high-traffic consumer products.
• Multi-cloud (AWS + GCP), cloud migration, or account consolidation experience; familiarity with BigQuery or similar data platforms.
• Knowledge of networking and security, such as VPN / zero trust and compliance.