Word of the Day

idempotent

/ aɪˈdɛmpətənt /

Part of speech: adjective

Vietnamese: bất biến khi lặp lại (tính lũy đẳng) — thực hiện nhiều lần cho kết quả giống lần đầu

What it means in plain English:

An operation is idempotent if doing it once produces the same result as doing it multiple times. The second, third, or hundredth call has no additional effect beyond the first.

Example Sentences

  1. REST API context: “We designed the payment endpoint to be idempotent — if the client retries after a network timeout, the charge won’t be processed twice.”

  2. Database operations: “The migration script is idempotent, so you can safely run it multiple times without corrupting the schema.”

  3. Microservices: “In an event-driven architecture, consumers should treat message handlers as idempotent because the message broker may deliver the same event more than once.”

Further Reading

Vocabulary Table

PhraseVietnameseExample in Context
idempotentbất biến khi lặp lại”Ensure your DELETE endpoint is idempotent — deleting a resource that no longer exists should return 204, not an error.”
scalabilitykhả năng mở rộng”Horizontal scalability means adding more servers; vertical scalability means upgrading the existing ones.”
fault-tolerantchịu lỗi tốt”A fault-tolerant system continues operating correctly even when one or more of its components fail.”
throughputthông lượng (lượng xử lý trong một đơn vị thời gian)“After switching to async processing, our throughput increased from 500 to 4,000 requests per second.”
latencyđộ trễ”End-to-end latency spiked during the deploy because the new pod took 30 seconds to warm up its cache.”

Pronunciation Guide

Focus Word: idempotent

Stress pattern: i - DEM - po - tent

The stress falls on the second syllable — say it like: “eye - DEM - puh - tent”

i       DEM      po      tent
●       ●●●      ●       ●●●●
weak   STRONG   weak    medium

Common mistake: Many non-native speakers stress the first syllable (“EYE-dem-po-tent”). This sounds unnatural to English speakers. Push the weight to -DEM-.

Practice Sentence

“An idempotent API endpoint ensures that retrying a failed request won’t cause duplicate side effects.”

Breakdown:

ChunkNotes
An i-DEM-po-tentStress on DEM; the article “an” links smoothly into the word
A-PI end-pointAPI = three separate letters: “AY - PEE - EYE”; stress on end in endpoint
en-SURES thatStress on second syllable of “ensures”; links into “that” without a pause
RE-try-ing a failed re-QUESTStress on first syllable of “retrying”; stress on second syllable of “request”
won’t CAUSE du-pli-cateShort and punchy on “cause”; “duplicate” = DU-pli-cut (three syllables, not four)
SIDE ef-fectsCompound noun — stress on the first word

Tip: Record yourself saying this sentence, then play it back at 0.75x speed. Listen for where your stress lands and compare to native speaker recordings on YouGlish.

Exercise 1 — Fill in the Blank

Context: You are in a system design discussion. Choose the correct word from the box.

Word bank: idempotent · latency · scalability · fault-tolerant · throughput

  1. “We need to think about __________ early in the design — once we have 10x the users, can this architecture handle it without a full rewrite?”

  2. “The service mesh makes our cluster more __________ by automatically rerouting traffic away from unhealthy pods.”

  3. “Users in Southeast Asia are complaining about slow load times. The problem is network __________ — the origin server is in Frankfurt.”

  4. “Make sure the webhook handler is __________ — Stripe will retry on timeout, and we can’t charge the customer twice.”

  5. “After we moved to batch inserts, database write __________ jumped by 300%.”

See Answers
  1. scalability — “We need to think about scalability early in the design…”
  2. fault-tolerant — “The service mesh makes our cluster more fault-tolerant…”
  3. latency — “The problem is network latency…”
  4. idempotent — “Make sure the webhook handler is idempotent…”
  5. throughput — “database write throughput jumped by 300%“

Exercise 2 — Translate Vietnamese → English

Read each architecture concept description in Vietnamese. Write a natural English sentence that expresses the same idea. Try to use the vocabulary from today’s table.

1. “Hệ thống của chúng tôi có thể tự phục hồi khi một node bị lỗi vì chúng tôi đã thiết kế nó để chịu lỗi tốt.”

Your answer: ___________________________________________

2. “Vì endpoint này là bất biến khi lặp lại, client có thể gửi lại request mà không sợ tạo ra bản ghi trùng lặp trong cơ sở dữ liệu.”

Your answer: ___________________________________________

3. “Độ trễ cao là vấn đề nghiêm trọng đối với ứng dụng giao dịch thời gian thực — người dùng không thể chờ hơn 100ms.”

Your answer: ___________________________________________

See Answers

1. “Our system can recover automatically when a node goes down because we designed it to be fault-tolerant.”

(Also natural: “Because we built fault tolerance into the architecture, the system continues operating even when individual nodes fail.”)

2. “Because this endpoint is idempotent, the client can safely retry the request without worrying about creating duplicate records in the database.”

3. “High latency is a serious problem for real-time transaction applications — users cannot wait more than 100 milliseconds.”

(Also natural: “For real-time trading systems, high latency is unacceptable — every millisecond counts.”)

Idiom of the Day

”single point of failure”

Vietnamese: điểm hỏng duy nhất — nếu nó hỏng, cả hệ thống sập

Literal meaning (architecture): A component in a system that, if it stops working, brings down the entire system. Good architecture eliminates single points of failure through redundancy and replication.

Metaphorical meaning (people & teams): One person or process that everything else depends on. If that person leaves, gets sick, or is unavailable, the whole workflow breaks.

Usage Examples

  1. Technical context: “The primary database with no replica was a single point of failure — the night it went down, the entire platform was offline for six hours.”

  2. Team/human context: “Jake is the only one who knows how to deploy to production. He’s a single point of failure for the whole release process — we need to document that and cross-train someone else.”

How to use it naturally:

  • “We need to eliminate this single point of failure before launch.”
  • “Don’t let any one person become a single point of failure on your team.”
  • “The load balancer itself became a single point of failure — ironic, given its purpose.”

Build your architecture English vocabulary by watching engineers explain real systems in English:

1. System Design Interview — Alex Xu (YouTube) Search: “System Design Interview channel YouTube” Why: Real interview conversations using terms like idempotent, consistency, throughput, and CAP theorem. You hear how experienced engineers actually speak about these concepts — not textbook English.

2. TechWorld with Nana Search: “TechWorld with Nana Kubernetes” Why: Nana explains Kubernetes, Docker, and microservices with clear, slow, precise English. Great for following along because her vocabulary is technical but her delivery is accessible. Watch with subtitles first, then without.

3. ByteByteGo (YouTube + Newsletter) Search: “ByteByteGo system design” Why: Short animated videos (under 5 minutes) that diagram complex concepts — rate limiting, idempotency, load balancing — while a narrator explains each piece. The narration script is clean, formal English you can copy directly into your own writing.

Morning Challenge

Time required: 5 minutes

Open your most recent pull request description (or the last Jira ticket you wrote). Read through it once.

Now rewrite just the summary paragraph using at least three of today’s words: idempotent, latency, and fault-tolerant.

If none of the words apply naturally to your current PR — write one sentence for each word describing a hypothetical improvement you could make to the system you are working on right now.

Example output:

“This PR makes the order-confirmation webhook handler idempotent so retries from the payment gateway don’t create duplicate records. It also reduces response latency by moving the email dispatch to a background queue. The updated architecture is more fault-tolerant because the webhook can now succeed even if the email service is temporarily down.”

Post your rewritten paragraph in a comment on the PR itself. Writing for a real audience, in a real place, is what makes vocabulary stick.

Good morning. One word, used precisely, is worth ten used vaguely. Make idempotent yours today.

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