Core backend concepts from concurrency and error handling to API design and service architecture.
Understand PostgreSQL internals from EXPLAIN plans to the storage engine, indexing strategies, and zero-downtime migration patterns.
Modern Java for backend services: virtual threads, GraalVM native images, streams pipelines, async composition, and an honest comparison against Go on a real workload.
Go 1.26 makes the Green Tea garbage collector the default. What actually changed, how to measure GC CPU before and after on your own workload, and the short window you have to opt out.
Slow JVM cold start breaks scale-to-zero and autoscaling. Three ways to fix it in 2026 — Project Leyden's AOT cache, GraalVM Native Image, and CRaC — with the exact commands, the trade-offs, and a decision framework.
Go context.Context: constructors, cancellation, deadlines, request values, and five goroutine leak patterns in production.
Kafka producer configuration: acks, idempotence, batching, compression, and the tradeoffs that matter for throughput and durability.
Postgres EXPLAIN plans: node types, cost interpretation, and six patterns that kill query performance on large datasets.
Handle unpredictable JSON in Go: map[string]any, json.RawMessage, type switches, and defensive patterns for shifting schemas.
Go graceful shutdown: SIGTERM handling, health probe coordination, and Kubernetes drain patterns for zero dropped requests.
Why exactly-once is a myth, and how idempotency keys, database constraints, and the outbox pattern make retries safe in Go and Java.
Java collections: computeIfAbsent, getOrDefault, removeIf, immutables, and Comparator chains that eliminate entire bug categories.
Stop fighting java.util.Date. Master LocalDateTime, ZonedDateTime, Instant, and Duration — predictable, thread-safe time handling.