Amazon OA2 Work Simulation | Keep Walking

Amazon OA2 Work Simulation | Keep Walking

目前两大原则：

1. requirement排在第一, deadline第二
2. 有manager出现的选项无脑选manager，manager就是一个组的代言人+保护伞，大哥自己人。

注意事项:

1. 时间充足, 仔细读题, 慢慢做
2. 那个打分并不是每个都要1, 2, 3, 4, 5, 因为你可以打比如2个5, 3个4也是可以的，所以还是很多变数的
3. 记的每收到email就要看看, email中会有后面的题目需要的信息

13. Database metric generation

Please rate the effectiveness of each response option for meeting the deadline.

1. Work on the project on your own putting in extra effort to finish on time.
2. Work on the project on your own until Priya is available, then continue to work on it together.
3. Work on the project with Ben being sure to watch his work closely because of this lack of experience.
4. Tell your manager you will not be able to complete the project in the time available.
5. Cut features from the product so you will be able to meet the two week deadline.
6. Start working on the project right away with Ben. Then ask Priya to contribute what (left?)

Answer:

• 一定要先告诉Manager有不能按时完成的风险, 所以4评5; 同时利用一切可以利用的资源来尽可能按时完成任务, 6评5;
• 然后2, 3评4分吧, 利用了一部分资源
• 1自己单干, 精神可嘉, 但是感觉浪费了点资源, 评3分吧
• 5减功能, 这个还是算了吧, 宁愿自己苦一点, 也要争取按时完成计划啊, 评1分吧
• 总结 344515

14. 别的Team要依赖于你的项目, 需要你把原先2周的活在用一周完成

Please rate the effectiveness of each response option for completing this work on time:

1. Ask your whold team for help, explaining the urgency that another is blocked.
2. Work with the Customer Incentives Team to identify the critical features that they need by the deadline and focus on those.
3. Push the timeline back another week to ensure there is enough time for all work to be completed accurately.
4. Ask your manager for help in determining the best approach to meet the new deadline.
5. Put in extra hours yourself to make sure everything gets done on time.

Answer:

1. 报告Manager是首要的, 所以4评5分; 利用一切可以利用的资源按时完成, 1评4分
2. 5自己加班加点完成, 评3分
3. 2跟别的Team商量着加功能, 评2分吧
4. 3不能在规定时间内完成, 也没有沟通, 会影响其它Team的工作, 评1分
5. 总结下来是 42153

15. 系统是否升级

Retail Website Team是我们的客户, 我们答应了他们要做两个features. 说咱们现在要帮人做两个feature，一个让100%用户爽，还有个让20%的用户爽。但是咱们现在还要升级一下系统，升级系统会让我们自己组爽，但是升级会推迟帮忙做的feature，不升级吧，以后升级之后还得做一遍。
这题中心是不升级，要做feature，因为feature可以让用户获得快感。（之前的想法：首先不升级，因为会block其他组。而且这个工具其实是更针对自己组方便的，要做的就是先把承诺的feature做好，然后找机会再搞这个升级。）

1. 升级, 在deadline前完成feature 1, 在deadline后完成feature 2
2. 升级, 把Retail Website Team的需求推后, 这样可以让我们更有效率的服务用户
3. 不升级, 优先完成我们答应的features, 然后把我们其它项目的deadline向后推一下, 做系统升级,
4. 不升级, 完成我们答应的features, 然后再找时间升级
5. 升级, 把Retail Website Team的需求推后, 因为这样可以避免我们做同样的事两次
6. 不升级, 因为这样对Retail Website Team没什么重大的影响, 我们要focus on Retail Website Team的需求上

Answer:

• 首先是不升级吧, 虽然1很好, 也很合理, 但是如果客户至上的话, 还是优先满足客户需求吧
• 在不升级中, 4我觉着最好, 找时间以后升级, 3其次, 6是说, 以后也不升级了, 这不好
• 在升级中, 1最好, 2其次, 5最差
• 总和起来, 从好到坏排: 4, 1, 3, 6, 2, 5, 如果是1-5分评分的话, 我会评4, 1, 3, 5, 1, 2

16. Customer Complaints on Recommendation Service

17. New Product Design

总共有8 weeks的时间, 安排工作任务.

Feature	Engineer Estimate of Time to Develop	Product Manager's Prioritization of Benefit
A	1 to 2 weeks	Medium
B	4 to 6 weeks	High
C	2 to 4 weeks	Low
D	2 to 4 weeks	Medium
E	5 to 9 weeks	High
F	3 to 5 weeks	High
G	2 to 4 weeks	Medium
H	1 to 2 weeks	Low

Rate the effectiveness of each of the following options:

1. F, G
2. A, B, D
3. A, C, D, G
4. A, D, F
5. A, C, F
6. A, C, D, G, H

Answer:
这个题目是要做一个时间和优先级的权衡.

1. 优先做优先级更高的feature
2. 时间安排要合理

High: B, E, F
Medium: A, D, G
Low: C, H

Option	Time	Features	Rank	Comment
F, G	5-9	1 1 0	4	时间安排不够紧凑, 浪费时间
A, B, D	7-12	1 2 0	2	任务安排合理, 但是时间略紧
A, C, D, G	7-14	0 3 1	5	没有完成任何一个高优先级的工作
A, D, F	6-11	1 2 0	1	任务安排合理, 也能够在规定时间内完成
A, C, F	6-11	1 1 1	3	在有限的时间内应该尽可能完成高优先级的任务, 所以最好不要完成Low的任务
A, C, D, G, H	8-15	0 3 2	6	没有完成任何一个高优先级的工作, 时间太紧, 基本无法按时完成

1. 先把A, C, D, G和A, C, D, G, H比较, 因为这两个里没有High的任务, 所以这两个最差, 但是A, C, D, G的时间要合理些.
2. 再比较F, G和A, C, F, 都是只完成了一个High, 一个Medium, 然后A, C, F多做了一个Low, 我是觉着A, C, F要好些, F, G的时间太宽裕, A, C, F至少比F, G多干了一个活
3. 最后是A, B, D和A, D, F的比较, 完成的任务数量和优先级是一样的, 这里就要考虑时间了. A, D, F的耗时是6-11, 总共有8 weeks, 比A, B, D的7-12合理

18-20. Last part of code

18 What is the problem with the Product.wasPurchasedByUser()?

1. It will run slowly because algorithm complexity is O(n^2)
2. It will run slowly on large datasets because more than one user could have purchased the same product.
3. It will run slowly because algorithm complexity is O(n^3)
4. It has performance issues.

1 2 3 4 5 6 7 8 9 10 11

class Product { public boolean wasPurchasedByUser(Shop shop, User user) { for(ShoppingCart shoppingCart : shop.getShoppingCarts()) { for(Product product : shoppingCart.getProducts) { if(product.getId() == this.getId() && shoppingCart.getUser().getUserId() == user.getUserId()) { return true; } } } } }

• 这个方法的作用是判断一个商品有没有被一个特定的用户购买. 这个方法会遍历所有的shopping cart, 然后遍历shopping cart中所有的商品, 会很慢.
• 选项2, 前半部分对, 后面because more than one user could have purchased the same product. 这个原因不对. 即使只有一个用户买了这个商品, 运行速度依然很慢
• 选项4是正确的

19 What is the most effective way of improving the ShoppingCart() class for the long term?

1. ShoppingCart should not override the user property every time new product is added to it.
2. Make Shopping Cart a property of Product class to improve performace.
3. Change the design of Shopping Cart by removing ShoppingCart.user and making shopping cart a property of User instead.
4. Product should have getUser() method so that we know what user has added it to his/her shopping cart.

经过18题的分析, 可以比较容易的得出, shopping cart应该做为user的一个属性存在. 所以选3

20 5个测试用例, 看哪个会通过, 哪个会失败, 面经上的是对的
Test1 失败, getDefaultPaymentMethod() 返回 null
Test3 失败, 构造函数中没有初始化email
Test5 失败, setPrice()中的参数是Integer, 会把10.75强制转化成Integer

21. Problem with the website

Jacob发邮件来说线上网站遇到了问题, 他不知道为什么, 来寻求帮助. 然后要向Jacob提问, 给以下问题的重要性评分

1. Do any other projects depend on fixing this problem?
2. How long will it take to solve this problem?
3. How does this affect customers?
4. Are we receiving complaints from customers?
5. How many customers is this affecting?
6. If I help you with this problem, will you help me finish my work today?

我觉着跟用户相关的都可以评5分, 谁让Amazon用户至上呢; 然后1评4分吧, 这个也很重要; 2问要花多长时间, 我觉着Jacob都不知道是什么问题, 怎么来估计时间呢, 所以不太现实, 评3分吧; 然后6, 显得有点自私, 一定要评1分. 总结一下 435551

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