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LetsGit.IT/Categories/Monoliths
Monolithsmedium

What is a modular monolith?

Tags
#modular-monolith#architecture#evolution
Back to categoryPractice quiz

Answer

A modular monolith is still one deployable unit, but with strong internal module separation. Each module owns its domain and communicates through well‑defined interfaces, improving maintainability and making future extraction to services easier.

Advanced answer

Deep dive

Expanding on the short answer — what usually matters in practice:

  • Context (tags): modular-monolith, architecture, evolution
  • Scaling: what scales horizontally vs vertically, where bottlenecks appear.
  • Reliability: retries/circuit breakers/idempotency, observability (logs/metrics/traces).
  • Evolution: keep changes cheap (boundaries, contracts, tests).
  • Explain the "why", not just the "what" (intuition + consequences).
  • Trade-offs: what you gain/lose (time, memory, complexity, risk).
  • Edge cases: empty inputs, large inputs, invalid inputs, concurrency.

Examples

A tiny example (an explanation template):

// Example: discuss trade-offs for "what-is-a-modular-monolith?"
function explain() {
  // Start from the core idea:
  // A modular monolith is still one deployable unit, but with strong internal module separatio
}

Common pitfalls

  • Too generic: no concrete trade-offs or examples.
  • Mixing average-case and worst-case (e.g., complexity).
  • Ignoring constraints: memory, concurrency, network/disk costs.

Interview follow-ups

  • When would you choose an alternative and why?
  • What production issues show up and how do you diagnose them?
  • How would you test edge cases?

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