Question 1

What is two-phase commit and its drawbacks?

Accepted Answer

**Target Audience:** Developers who know what a database transaction is and now meet data spread over several databases or services. No distributed-systems background assumed.
**Difficulty:** Medium
**Verified with:** Node 22.22 and Python 3.12 (both print identical output).

> **How to read this doc:** Every idea is explained in plain language first, then tagged with `📌 Interview term:` so you also learn the exact words an interviewer expects. All timings and counts come from running the examp

Question 2

What are the trade-offs of microservices vs a monolith?

Accepted Answer

**Target Audience:** Beginners to architecture — you have built a web application; every term is defined the first time it is used.
**Difficulty:** Medium
**Verified with:** Node 22.22 and Python 3.12 (both print identical output). Hop latencies, availabilities and memory sizes are stated assumptions. The case studies are cited to their published coverage (InfoQ, July 2018, on Segment; DevClass, May 2023, on Prime Video), checked October 2026.

> **How to read this doc:** Plain language first, t

Question 3

What is the saga pattern for distributed transactions?

Accepted Answer

**Target Audience:** Developers who build or interview for microservice back ends. You know what a database transaction is; no distributed-systems background assumed.
**Difficulty:** Medium
**Verified with:** Node 22.22 and Python 3.12 (both print identical output).

> **How to read this doc:** Every idea is explained in plain language first, then tagged with `📌 Interview term:` so you also learn the exact words an interviewer expects. All behaviour shown comes from running the example; the **V

SYSTEM DESIGNDECODED.

Medium

What is two-phase commit and its drawbacks?

What are the trade-offs of microservices vs a monolith?

What is the saga pattern for distributed transactions?