# LLD / Machine-Coding Rounds — Current Landscape

**Researched:** 2026-08-18
**Recency rule applied:** only 2025–2026 sources retained. Reports from 2021–2024 were found and
deliberately discarded — the format has changed materially (Karat removal, AI-assisted rounds,
Google's code-comprehension pilot), so older experiences would train for the wrong event.

---

## Headline finding, stated plainly

**Google L4 has no dedicated LLD or system-design round.** Google reserves system design for L5
and above. The L4 loop is: Google Hiring Assessment → recruiter screen → one technical phone
screen (45–60 min coding) → onsite of 2–3 coding rounds (45 min each) plus one behavioural
("Googliness"). Hiring committees weight coding most heavily.

So "system design rounds for Google L4" is a mismatch with how Google actually hires at that
level. The round being described — a blank editor, a product-shaped problem, produce working
classes under a clock — is real and common, but it belongs to **Uber, Atlassian, Salesforce, and
the Indian product companies**, not to Google L4.

Two live 2026 changes matter more for Google specifically:

- **May 2026:** Google announced a pilot replacing one traditional coding round with an
  open-ended **"code comprehension"** round for junior and mid-level SWE on select US teams
  (starting Google Cloud and Platforms & Devices), rolling out through H2 2026. Format: a 200–500
  line unfamiliar codebase in CoderPad, 60 minutes, read it, find bugs, discuss design decisions,
  suggest improvements — **with Gemini available as an assistant**. Scored on AI fluency: prompting,
  validating output, debugging. It sits *alongside* one remaining traditional coding round, not
  instead of all of them. Still a limited pilot; most L4 candidates will not see it yet.
- Google is shifting toward requiring **at least one in-person round**, attributed to
  AI-assisted-cheating concerns.

## Company-by-company

### Uber — yes, a real machine-coding round
- Dedicated LLD round is **now standard for SDE-2**. 45–60 minutes.
- Emphasis: clean OOP design and **extensibility**; complete, working implementations.
- **The code is compiled and executed.** It must run.
- Observed problem space: rate limiter, in-memory file system, parking lot, trip state machine,
  truck tracking system.
- Platform: CodeSignal. Loop: recruiter → 70–90 min CodeSignal OA (4 problems) → phone screen →
  4–6 round onsite → hiring committee, 2–6 weeks end to end.
- Judged on: data structures, design patterns, language proficiency, single-responsibility class
  decomposition, naming, readability.

### Atlassian — yes, and the format has a signature move
- **Karat has been dropped.** The "Coding Design" stage is now two rounds: one DSA, one LLD.
- Observed LLD problems: Customer Satisfaction system, Middleware Router, Game of Snakes, Cost
  Explorer, Rating System. Earlier years: snake game, rate limiter, parking lot.
- **The distinguishing signal is a mid-round scale-up requirement.** Atlassian expects a design
  where the new requirement costs minimal change. Negative feedback clusters on exactly two
  things: solving the problem but **not validating edge cases**, and **rewriting large portions**
  of the code when the scale-up lands.
- Atlassian recycles a **small question bank** — candidates who drilled the recurring set did
  better. This is the one company where targeted memorisation genuinely pays.
- 2026 reports describe interviewers as patient and process-focused, scoring thought process over
  the final answer.

### Salesforce — yes, and it is explicitly Java + concurrency
- SMTS loop: a design round with **two problems** (SOLID, caching, design patterns, LLD, UI/UX
  considerations) and a separate **60-minute machine coding round based on Java, multithreading,
  concurrency, and thread safety**.
- **July 2026 report:** 90-minute LLD+HLD round, design a **Notification Service** resembling a
  real product (Klaviyo-like), described as tough and deliberately **ambiguous** — significant time
  went just to understanding the problem. Explicitly *off-template*.
- Takeaway: Salesforce is the company least served by memorising the classic catalogue, and the
  one where thread-safety is a first-class scored dimension rather than a follow-up question.

### Meta — related round, different shape
- **Product Architecture**, 45 minutes: define requirements, design the APIs, draw a high-level
  diagram. Product-mindset weighted over raw backend scalability.
- **From 2026-04-16, Product Architecture was replaced by "AI-Enabled Product Architecture."**
- Some interviewers narrow the round to API design or low-level component design; scope varies by
  interviewer.
- Not a machine-coding round — no requirement to produce running code.

### Indian product companies — the densest concentration of this format
Flipkart, Swiggy, Cred, Razorpay, PhonePe, Ola, Groww, Udaan. **90–120 minutes**, used from SDE-1
through SDE-4. This is where the round is most standardised and most drillable.

---

## The composite rubric

Weightings reported for machine-coding rounds:

| Dimension | Weight |
|---|---|
| Code design & structure (class organisation, naming, separation of concerns) | 30% |
| Working functionality (it compiles, it runs, it is correct) | 25% |
| Design patterns & SOLID | 20% |
| Extensibility (add a feature without modifying existing code) | 15% |
| Edge cases & error handling | 10% |

Cross-cutting: **the code review is 30–50% of the evaluation.** The code alone does not carry the
round. Interviewers ask "why Strategy here?", "how would you add feature X?", "what changes under
concurrency?" — and score the answers.

**A driver/demo `main` is non-negotiable.** Interviewers run it first. Unit tests are not
universally required, but testability is scored, and at Salesforce concurrency tests are in scope.

## The reported time-box

| Phase | Minutes |
|---|---|
| Requirement extraction & design | 10–15 |
| Core models / entities | 15–20 |
| Business logic | 25–30 |
| Driver code | 10 |
| Edge cases & polish | 5–10 |

## Problem catalogue by frequency

- **Tier 1 (must):** Parking Lot, Snake and Ladder, Vending Machine, Shopping Cart
- **Tier 2 (frequent):** Elevator, Chess, Restaurant/Food Ordering, Movie Ticket Booking
- **Tier 3 (advanced):** Rate Limiter, Notification Service
- **Also reported 2025–2026:** Splitwise-style expense splitter, ride-matching/Uber-lite, LRU cache
  with custom eviction, food-delivery order tracking, in-memory file system, Cost Explorer,
  Middleware Router, Rating System, Customer Satisfaction system

---

## What this implies about the "goes blank" gap

The gap is not a knowledge gap about design patterns. Nothing in the rubric rewards naming
patterns. What the rubric rewards, and what passive video-watching never rehearses:

1. **Requirement extraction from an ambiguous prompt in 10–15 minutes** — the Salesforce
   Notification Service round was mostly this. Untrained, this phase either gets skipped (leading
   to the wrong design) or eats half the clock.
2. **Typing an entity skeleton fast enough that it costs no thought** — enums, immutable value
   objects, interface seams. This is muscle memory, and it is trainable in isolation.
3. **Absorbing a mid-round requirement change without rewriting** — Atlassian's explicit
   discriminator, and the thing the blank-page feeling actually predicts.
4. **Defending decisions aloud during code review** — 30–50% of the score, and 0% of what solitary
   silent practice rehearses.
5. **Finishing.** Working code beats elegant unfinished code, because functionality is 25% and an
   unrunnable submission forfeits it.

Each of those is a separate drill. Practising "do a whole LLD problem" trains all five badly at
once; the first three are better trained apart and then assembled.

---

## Sources

- [Google L4 Interview Guide — Hello Interview](https://www.hellointerview.com/guides/google/l4)
- [Google's Interview Process (2026) — TechPrep](https://www.techprep.app/blog/google-interview-process)
- [Google's New Code Comprehension Interview Round — Final Round AI](https://www.finalroundai.com/blog/google-code-comprehension-interview)
- [Google SWE onsite 2026 — code comprehension round with Gemini](https://www.finalroundai.com/community/t/google-swe-onsite-2026-the-code-comprehension-round-with-gemini-is-completely-different-from-what-leetcode-prep-covers/228)
- [Google Coding Interviews in 2026: What Changed — Levelop](https://levelop.dev/blog/google-coding-interviews-in-2026-what-changed-and-what-didnt)
- [Uber's Interview Process (2026) — TechPrep](https://www.techprep.app/blog/uber-interview-process)
- [Uber L4 Interview Experience — Medium](https://khaniqbal.medium.com/uber-l4-interview-experience-5350c0e5918d)
- [Uber SDE 1 (2025) Interview Experience — Medium](https://medium.com/@quoteblogs/uber-sde-1-2025-interview-experience-8cf313833d1b)
- [Atlassian LLD questions from recent interviews — Medium](https://medium.com/@prashant558908/atlassian-low-level-design-questions-from-recent-interviews-d09c463c0889)
- [Atlassian Interview Experience | SWE | India | P40 — LeetCode](https://leetcode.com/discuss/post/7412653/atlassian-interview-experience-swe-india-rhrg/)
- [Atlassian Interview Experiences 2026 — CodingKaro](https://www.codingkaro.in/jobs-internships/leetcode-interview-experience/Atlassian)
- [Salesforce SMTS Hiring Drive July 2026 — LeetCode](https://leetcode.com/discuss/post/8428080/)
- [Salesforce | MTS | Interview Experience | 2026 — LeetCode](https://leetcode.com/discuss/post/7561138/salesforce-mts-interview-experience-2026-nl4g/)
- [Salesforce's Interview Process (2026) — TechPrep](https://www.techprep.app/blog/salesforce-interview-process)
- [Meta Product Architecture Interview: How to Prepare — Hello Interview](https://www.hellointerview.com/blog/how-to-prepare-meta-pa)
- [Meta AI-Enabled Product Architecture discussion — Hello Interview](https://www.hellointerview.com/community/discussion/meta-ai-architecture-interview)
- [Meta System Design Interview (2026 Guide) — Exponent](https://www.tryexponent.com/blog/meta-system-design-interview)
- [Machine Coding Round: Complete Interview Preparation Guide — Low Level Design Mastery](https://www.lowleveldesignmastery.com/blog/machine-coding-round/)
- [Top 20 Low Level Design Interview Questions (2026)](https://www.lowleveldesignmastery.com/blog/low-level-design-interview-questions/)
- [Low Level Design in a Hurry — Hello Interview](https://www.hellointerview.com/learn/low-level-design/in-a-hurry/introduction)
- [Types of LLD interviews — AlgoMaster](https://algomaster.io/learn/lld/lld-interview-types)
- [Machine Coding Round and LLD — workat.tech](https://workat.tech/machine-coding)
- [What to Expect in a Low-Level Design Interview Round — Design Gurus](https://www.designgurus.io/answers/detail/what-to-expect-in-a-low-level-design-interview-round)
