We are hiring a senior scalability engineer to help prepare a modern microservices backend for high-concurrency production usage. This role is focused on backend performance, reliability, capacity planning, async workflow design, database scalability, and observability. This is not a generic DevOps-only role. We are looking for someone who can reason deeply about how backend systems behave under load: database pressure, queue depth, retries, rate limits, stuck jobs, async workflows, API latency, and failure recovery. Responsibilities Analyze backend architecture and identify scalability bottlenecks across APIs, services, database, cache, queues, storage, and third-party integrations. Design and execute load tests for high-concurrency user flows. Tune Postgres queries, indexes, connection pools, pagination, and transaction patterns. Design reliable queue/background-job systems with retries, idempotency, dead-letter queues, and reconciliation jobs. Define observability for scale: metrics...