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How to integrate GPT-4 in enterprise microservices

Practical patterns to add LLM-powered capabilities to existing services while meeting enterprise constraints: security, performance, observability, and cost. These are the battle-tested lessons from migrating regulated workloads to intelligent services in 2024-2025.

Updated Nov 8, 2025 6 minute read Enterprise-grade checklist
Diagram representing LLM-enabled microservices architecture

Architecture at a glance

01
  • Sidecar or dedicated "AI adapter" service for prompt construction and response shaping
  • Async workflows via queues (Kafka / SQS) for long-running or batch jobs
  • Guardrails: input validation, PII redaction, output moderation, schema validation
  • Observability: structured logging, trace IDs, prompt/response redaction, cost/latency metrics

Security & compliance

02
  • Use server-side API keys; never expose keys in clients
  • Encrypt secrets (AWS KMS/Secrets Manager), enforce VPC endpoints where available
  • Mask PII before sending to the LLM; log only redacted prompts

Latency & cost controls

03
  • Prefer smaller/faster models for classification or routing; reserve GPT-4 for complex reasoning
  • Cache deterministic prompts (embedding search, canned summaries, templated responses)
  • Batch compatible requests and tune max_tokens / temperature per use-case

Patterns that work

04
  • Tool-using agents to call internal services (profile lookup, transactions, domain-specific APIs)
  • Validation layer using JSON Schema or Zod to ensure outputs are machine-usable
  • Prompt templates versioned and A/B tested with feature flags for safe rollout