Coinbase OA 面经大放送｜算法、SQL、逻辑题全覆盖

要说 Coinbase OA ，真的是比一般互联网公司的更有意思一点。作为全球最大的加密货币交易平台之一，他们在招聘环节尤其看重候选人的逻辑和代码功底。OA 不只是单纯刷题，很多题目都带点交易业务的味道，比如订单撮合、价格分析或者交易异常检测。刚拿到题的时候，可能觉得跟常规 OA 差不多，但仔细做就会发现，细节上还是有不少坑。

Coinbase 的 OA 一般在 Codility 或 HackerRank 上测，时间大概 70 到 90 分钟。整体是 2 到 3 道编程题，有时还会掺杂一点 SQL 或者数据清洗的小题。难度在中等偏上，主要考察三个方面：

1. 代码的正确性（能不能跑通所有 case）；
2. 时间复杂度（别超时）；
3. 可读性（代码是不是清晰）。

常见题型围绕数组、哈希表、区间处理、字符串操作，但题目背景会结合金融场景，比如撮合引擎、价格波动、异常交易检测之类的。做题时感觉既像算法题，又有点业务味道。

Coinbase OA 真题分享

Question 1

What does event.stopPropagation() do?

Select the correct answer:

• It stops the event from bubbling through the element’s descendants.
• It stops the default behavior of the element being clicked.
• It stops other event handlers on the element from firing.
• It stops the event from bubbling through the element’s ancestors.
• I don’t know

Question 2

In what order does f receive its arguments?

Language: Javascript

f("foo");  
setTimeout(function() { f("bar"); }, 0);  
f("baz");  

Select the correct answer:

• foo baz bar
• foo bar baz
• foo baz
• bar foo baz
• I don’t know

Question 3

What does the following code do?

Language: Javascript

str.split("dog").join("cat")  

Select the correct answer:

• Replaces every occurrence of the word “dog” in a string with the word “cat”
• Finds the word “dog” in a string, and appends “cat” at that location
• Creates an iterator from “dog” to “cat” in the string
• Appends “dogcat” to the end of a string
• I don’t know

Question 4

Which of the following selectors will make Text pink?

Language: Html

Select the correct answer:

Replaces every occurrence of the word "dog" in a string with the word "cat"
Finds the word "dog" in a string, and appends "cat" at that location
Creates an iterator from "dog" to "cat" in the string
Appends "dogcat" to the end of a string
I don't know
Question 20
Which of the following selectors will make Text pink?

Language: Html

Select the correct answer:

• div.elem { color: pink; }
• #id { color: pink; }
• .wrapper.elem { color: pink; }
• .wrapper:nth-child(1) { color: pink; }
• I don’t know

Question 5

What technique would dramatically improve the performance of the following function?

Language: Plain

fun fib(n: Long): Long {  
    return if (n <= 1) n else fib(n - 1) + fib(n - 2)  
}  

Select the correct answer:

• recursion
• bytecode compilation
• memoization
• divide-and-conquer algorithm
• I don’t know

Question 6

Consider the following Javascript code. The final output to the console is 0. Why?

Language: Javascript

function incr(num) {  
    this.count++;  
}  

incr.count = 0;  

let i;  
for (i=0; i<10; i++) {  
    if (i > 5) {  
        incr(i);  
    }  
}  

console.log(incr.count);  

Select the correct answer:

• this in incr doesn’t have a reference to incr.count.
• There’s a bug in the for-loop.
• This is caused by Javascript’s hoisting mechanism.
• console.log is async and therefore doesn’t reflect the most up-to-date value.
• I don’t know

Question 7

Which of the following is not an accurate statement regarding CAPTCHAs?

Select the correct answer:

• They have been criticized for exploiting unwitting labor
• They are used to distinguish users and bots
• Input solutions are manually verified
• A common implementation is based on the recognition of distorted text
• I don’t know

少走弯路，多拿 offer

Coinbase 的 OA 给我的感觉就是：不光看你能不能写出代码，还要看你能不能在紧张的时间里把思路理清，写得既对又快。如果你经常遇到“脑子里有点思路但写不完整”或者“卡在 debug 出不来”的情况，那真的没必要死撑。

在 Programhelp，我们做的不只是“代写”，而是帮你在考试中保持节奏感。通过远程无痕助攻，我们能及时提醒你哪些思路更高效、哪些坑要避免，甚至在关键 debug 节点拉你一把。很多同学靠着这点辅助，不光顺利过了 Coinbase 的 OA，还在 Robinhood、Stripe 这种金融科技公司拿到后续面试机会。

所以如果你正准备 Coinbase 的 OA，不妨找我们聊聊，少走点弯路，节省宝贵的备考时间，说不定下一个顺利过关的就是你。

jor jor

See Full Bio