How I Cracked Multiple Backend Interviews: Real Stories & Technical Deep Dives

Background

The author graduated in 2015 from a 985 university majoring in communications engineering, spent a year创业 in Beijing, and began looking for a corporate job at the end of 2016. With only one year of formal work experience, the author documents interview experiences for reference.

1. Afanti

First round

The first interview involved a written test focusing on Python fundamentals such as mutable vs immutable objects, garbage collection, and a simple database design question.

Second round

The interviewer reviewed the written test, asked about the author's projects, and posed basic system‑design questions before moving to a third round.

Third round

The CTO asked broad questions ranging from server deployment to Nginx details. The most memorable question was:

"Describe in detail what happens from the moment a browser sends a request until the response is returned."

The author answered by covering:

Network model: HTTP over TCP (or TLS for HTTPS), socket communication, lower‑layer protocols (ARP, RARP, OSPF, IEEE 802.x) and routing.

Application layer: HTTP request/response, stateless nature, POST vs GET, RESTful design, server handling via Nginx, uWSGI, and Django processing flow (middleware, routing, response construction).

2. XueTang Online

Similar interview flow with a backend engineer conducting the first round, a department manager for the second, and HR for the third. The focus was on Python, Django experience, and system design.

3. Guokr

The first round included a written test with database queries and a classic O(1) stack problem that required returning max/min values. The author discusses the design of such a stack and references the well‑known solution.

Second round

Technical questions covered TCP flow control (the author mistakenly mentioned congestion control), and deep database internals such as index principles and MySQL storage engines.

4. Veeva

Phone interview followed by a homework task (leap‑year function). The author emphasized writing clean, testable code and demonstrated object‑oriented design.

Four‑round interview

The final technical round required designing a short‑URL generation system with random strings, collision avoidance, and space efficiency.

5. Zhihu

Multiple rounds included project discussion, system design (e.g., WeChat red‑packet architecture), and algorithm questions such as quicksort and binary search.

6. Chunyu Doctor

Interview questions were practical, based on real project scenarios like grouping chat records. System design involved a QQ‑style chat tool with groups, media, and admin features.

7. 360

The interview emphasized Linux fundamentals; the author struggled with advanced Linux commands and felt mismatched with the Python‑focused role.

8. Toutiao

Five interview rounds covered:

First round: Python basics, Redis usage, hash‑table distribution issues, TCP, and a Fibonacci function.

def fib(n):
    a, b = 0, 1
    for x in xrange(n):
        a, b = b, a + b
    return b

Second round: Cache‑miss handling, single‑linked list reversal.

def reverse(node):
    p = node
    cur = node.next
    p.next = None
    while cur:
        tmp = cur.next
        cur.next = p
        p = cur
        cur = tmp
    return p

Third & fourth rounds: System design for multi‑device login, QR‑code login, database schema, and a final HR discussion.

Summary

The author ultimately accepted Toutiao’s offer, reflecting on the importance of leveraging campus recruitment, building personal projects, and continuously practicing interview problems.