Test Development Interview Preparation: Tips, Sample Questions, and Core Technical Knowledge

The author, a developer named XiaoLin, explains that students who start preparing for large‑company spring internships late may find it difficult to break into backend roles, but can consider test development positions as a less competitive alternative.

Test development roles offer similar salaries to backend positions (e.g., 22k per month, 35w+ annual) and involve both development and testing tasks, such as building testing tools and handling test‑related features.

Interview topics for test development include designing test cases, differences between black‑box and white‑box testing, manual versus automated testing, API testing tools, and personal motivation for choosing the role.

The article shares interview experiences from two major companies—Kuaishou and Didi—highlighting that while algorithm questions may appear, they are generally less intense than backend interviews, providing a shortcut to land a position.

Key database commands are listed: Insert – INSERT INTO table_name (column1, column2, ...) VALUES (value1, value2, ...); ; Delete – DELETE FROM table_name WHERE condition; ; Update – UPDATE table_name SET column1 = value1, column2 = value2, ... WHERE condition; ; Select – SELECT column1, column2, ... FROM table_name WHERE condition; .

The differences between MySQL and Redis are explained: MySQL stores data on disk in relational tables with rich data types and full persistence, while Redis stores data in memory with faster read/write, supports various data structures, offers optional persistence (RDB/AOF), and is suited for caching, messaging, and high‑speed scenarios.

HTTP vs. HTTPS differences are outlined: HTTP transmits data in plaintext, while HTTPS adds SSL/TLS encryption, uses port 443, and requires certificates for server authentication.

HTTPS security is broken down into data encryption, identity verification via certificates, and data integrity ensured by hash algorithms.

TCP reliability mechanisms include connection management (three‑way handshake, four‑way teardown), sequence numbers, acknowledgments, timeout retransmission, flow control via sliding windows, and congestion control (slow start, avoidance, fast retransmit, fast recovery).

Common Linux commands are summarized: ls (list directory), grep (search patterns), chmod (change permissions), top (resource usage), ps (process status), netstate (view ports).

Array vs. linked‑list differences are highlighted: arrays provide O(1) random access and better cache locality, while linked lists offer O(1) insertion/deletion but require O(n) traversal.

Test case design for a social‑media "like" feature is presented with six scenarios: normal like, cancel like, concurrent likes, like limit, cross‑device synchronization, and exception handling.

class ListNode {
    int val;
    ListNode next;
    ListNode(int x) { val = x; }
}

public class LinkedListDeletion {
    public ListNode deleteNode(ListNode head, int val) {
        if (head == null) {
            return null;
        }
        if (head.val == val) {
            return head.next;
        }
        ListNode prev = head;
        ListNode curr = head.next;
        while (curr != null) {
            if (curr.val == val) {
                prev.next = curr.next;
                break;
            }
            prev = curr;
            curr = curr.next;
        }
        return head;
    }
}

A SQL example to retrieve the highest score is shown: SELECT MAX(score) FROM grades;

public int binarySearch(int[] arr, int target) {
    int low = 0;
    int high = arr.length - 1;
    while (low <= high) {
        int mid = low + (high - low) / 2;
        if (arr[mid] == target) {
            return mid;
        } else if (arr[mid] < target) {
            low = mid + 1;
        } else {
            high = mid - 1;
        }
    }
    return -1; // target not found
}

Additional interview questions cover login interface testing (boundary values, state transitions, permissions, concurrency, cross‑platform, performance, security) and general queries about test development motivations.