Twilio

Role: Software Engineer (P2), Full-stack

College: Not Specified

Interview Date: June 2025

Interview Type: Full-Time

Result: Offer (Declined)

Difficulty: Medium

Rounds: 5 rounds (1 HR screening + 4 technical rounds)

Topics Asked: React, Node.js, REST API, State Management (useReducer), Low-Level Design, High-Level Design (WhatsApp-like app), Scalable Backend Architecture, APIs, Database Design, Behavioral

Experience:

This candidate, with 3 years of experience as an SDE-2, interviewed for a Software Engineer (P2) full-stack position in June 2025. The process took about 20 days. The recruiter reached out directly on LinkedIn.

1. HR Screening
Approximately 30 minutes. This round involved discussions about the candidate's background, career goals, and a quick overview of the company and the specific role.

2. Online Assessment (OA) — 90 minutes (HackerRank)
A full-stack test with automated test cases.

• 1 React question (focused on React hooks and basic REST API building).
• 1 Node.js question (focused on basic REST API building).

The questions were described as "nothing extremely difficult" if one knew React hooks and basic REST API building.

3. LLD (Low-Level Design) — Interactive on HackerRank
This virtual round on Google Meet focused on React + Node.js separately.

• React question: Build a user list with Add, Edit, Update, Delete, and Display functionalities. The expectation was to use `useReducer` for state management instead of just `useState` + prop drilling, with a constraint of no external libraries like Redux.
• Node.js question: Build 4 APIs (GET, POST, DELETE). One specific task involved calling an external API, processing its response, and returning combined data. The candidate faced strict test cases and couldn't finish all Node.js test cases due to time constraints but was selected for the next round.

4. HLD (High-Level Design) — 1 hour
The task was to design a WhatsApp-like application. Topics covered included frontend component design (chats, messages, groups), scalable backend architecture, designing the WhatsApp group feature, APIs, and database design. The candidate explained everything on a virtual whiteboard.

Overall Experience: The candidate found the process gave great exposure to full-stack interviews, system design, and negotiation. Although an offer was received, the candidate did not end up joining Twilio.