iClosed

Backend Engineer

• Own the performance and scalability of backend systems and the underlying data layer
• Design request flows, synchronous versus asynchronous work, state placement, dependency behavior, and scalable service boundaries
• Diagnose latency and performance issues using traces, execution plans, metrics, and evidence
• Establish instrumentation, review standards, and regression gates to prevent customer-visible problems
• Design strategies for read scaling, write scaling, read/write separation, background processing, real-time updates, traffic spikes, high availability, reliability, search, data growth, safe changes, and API efficiency
• Review feature-team architecture proposals
• Write design documents and decision records for other engineers to build from
• Select and optimize relational, document, key-value, and in-memory data stores based on workload and access patterns
• Diagnose execution plans, index costs, lock contention, connection pooling, replica lag, partitioning, document aggregation, shard keys, hot partitions, cache behavior, and dual-write issues
• Diagnose latency across the full request path, including ORM-generated traffic, synchronous and ETL latency, and third-party integrations
• Own data-layer capacity planning and cost per request alongside latency
• Introduce design and query reviews for hot paths and data-layer changes
• Define standards for migrations, index justification, and work that must not run synchronously
• Instrument data access in application traces
• Contribute CI regression gates and production-realistic load testing
• Investigate performance for the largest customer accounts and per-tenant behavior
• Join the escalation on-call rota once established

Principal Backend Engineer, Performance, Database