Backend Engineering
Webhook Signatures and Replay Protection: A Checklist
Secure webhooks with raw-body HMAC, constant-time comparison, signed timestamps, delivery deduplication, business idempotency, durable inboxes, and key rotation.
ZoyTown Engineering
Technical Articles
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Latest articles
30 articles
Backend Engineering
MongoDB Change Streams: Resume Tokens and Recovery
Build a recoverable MongoDB Change Streams consumer with opaque resume tokens, idempotent effects, CAS checkpoints, backpressure, backfills, and reconciliation.
AI Agent Engineering
Bedrock Agents Classic to AgentCore: A Migration Guide
Migrate Bedrock Agents Classic to AgentCore with account eligibility checks, capability mapping, shadow tests, rollout gates, and rollback-safe IaC.
Retrieval Engineering
RAG Retrieval Evaluation: Recall, MRR, and nDCG Checklist
Build a versioned RAG retrieval benchmark, select Recall@k, MRR, and nDCG@k deliberately, and gate chunking, latency, context budget, LLM judges, shadow traffic, and rollout.
Python
Python Free-Threading in Production: Compatibility and Gates
Evaluate Python 3.14 free threading with runtime GIL checks, C-extension qualification, shared-state audits, controlled benchmarks, canary thresholds, and a tested rollback to the regular build.
Backend Engineering
FastAPI OpenTelemetry Tracing: A Production-Ready Guide
Instrument FastAPI with OpenTelemetry, export OTLP through a Collector, control sampling and sensitive data, preserve background-task context, and verify the trace pipeline before production rollout.
Python
uv Workspaces and Lockfiles: A Reproducible Build Checklist
What uv.lock captures and why to commit it, when a workspace is the wrong tool, gating drift in CI with uv lock --check, Docker layer caching, and exporting lockfiles without losing the source of truth.
Backend Engineering
Redis 8.6 Upgrade Guide: XADD Idempotency, LRM Eviction, CVEs
Why to target Redis 8.6.5, how XADD IDMP and IDMPAUTO idempotent production works, sizing IDMP-DURATION and IDMP-MAXSIZE, LRM eviction, HOTKEYS, and a staged upgrade sequence with rollback gates.
Retrieval Engineering
MongoDB Hybrid Search: Fusing Vector and Text with $rankFusion
Combine $vectorSearch and $search in MongoDB with $rankFusion: version prerequisites, both index definitions, a working pipeline, input-pipeline constraints, and how to tune recall.
AI Agent Engineering
A2A 1.0 Migration Guide: Agent Cards, Tasks, and Streaming
Migrate A2A v0.3 systems to Protocol 1.0 with explicit interface negotiation, stream parsing, task authorization, idempotency, dual-stack rollout, and contract tests.
Backend Engineering
FastAPI Background Tasks: Celery or a Durable Workflow?
Choose between FastAPI BackgroundTasks, Celery, and durable workflows using persistence, retry, idempotency, outbox, HTTP 202, state, scheduling, and recovery requirements.
Open Model Engineering
Anthropic on Open Weights: A Release Framework for Developers
Analyze Anthropic’s open-weights position and apply practical gates for capability testing, model provenance, deployment isolation, and release decisions.