Chapter 4: Good and Bad Cache Practices

Cache can help reduce the load to the database and improve the service performance, however, designing and using the cache in the optimal way is one of the most tricky problems. In Doordash’s monolithic world, there were many anti-patterns cache usage, which makes cache itself a scalability issue. In this chapter, I am going to revisit the bad practices using cache, and discuss the right principles as well as some interesting cache problems.

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Chapter 3: How to Scale SQL Database?

Database is oftentimes the bottleneck of service scalability and reliability. Between 2018 and 2020, Doordash experienced multiple site wide outages during our traffic peak hours due to database issues. Before we are able to break down the monolithic service, we need to put off the database fires to ensure the team has enough room to focus on the service extraction. In this chapter, I am going to introduce how we scale the SQL databases.

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Chapter 1: Decouple Client and Backend through BFF Layer

In the monolithic world, doordash service only has two layers: a python Django monolithic service as the backend, and the client layer, including the web and mobile clients. The simple architecture worked well when the business and the team were small, as it enabled the product team to move fast. However it doesn’t scale as it increases the overhead maintaining the backend.

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Introduction to Monolithic to Microservice Extraction

The biggest issues Doordash faced in the past few years are reliability and scalability challenges. They are connected: since we can’t scale the server as the business grows, we crash very often. In the worst outage, Doordash lost millions of dollars since it had to pay for the prepared food to the merchant and send extra apology credit to the customer besides the refund.

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职场杂谈:如何有效推动跨职能合作

我们大多数人或早或晚都会经历过跨团队跨职能的合作项目。能够有效推动这样的项目是个人领导能力最好的证明,也常常是晋升到高级职位必须的历练和必备的资历。跨部门合作之所以困难本质上是权力不足造成的。作为项目的推动者,你往往并不具备对这些合作的组织的直接权力。你能倚靠的只有自己日常建立起来的影响力和推动这类项目的技巧。

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《候场》我把肚皮给你看

那一刻我担心地确认了一下前后没有车,因为视线模糊我无法稳定地前进。那一刻我满心感动,却不知道要跟谁说。那一刻我感到自己得到了理解,却因为不知道跟谁说起而再次感到孤独。我花了很多时间想要弄明白那打动我的究竟是什么。也许是李诞对人生的困惑让我得到了一点安慰。这安慰就是,世界上确实有很多敏感的人对人生的终极问题感到困惑,并且因为找不到答案而感到生命空虚。

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《传道书》 从虚无中寻找意义

开始学习之后不久我就读到了《传道书》。我很快就被书中弥漫的虚无主义的气氛吸引,作者在书中如同呓语一般反复吟咏:这也是空虚,如同捕风。他列举自己寻找人生意义的各种尝试,描述他对世界的种种观察,最后得出结论一切都是空虚。《传道书》极擅长通过修辞增强说服力,在不断重复人生空虚的感叹中形成一种奇妙的回响。我在这样反复的吟咏之中仿佛遇到了知音。因为那些消极的话语恰好符合那时我对人生的感受:如果我们对人生的各种答案多问一个为什么,总会发觉背后的无意义。

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《随机漫步华尔街》现代投资思想史

菲尔茨·杰拉德(F. Scott Fitzgerald)说,检验一流智慧的标准,是同时保有全然相反的两种观念还能正常行事。按照这样的说法,投资者中一流智慧的比例一定不低。你当然可以说投资者必须做到兼收并蓄,但是如果你相信,我们应该认真检查行动背后的思想,那么把这些关于投资的想法拿出来审视就十分有必要了。《随机漫步华尔街》同时具备投资思想简史和个人投资指南的气质。本书的大部分篇幅用于讨论不同的投资思想和理论,系统而且全面,但并不保证客观,因为作者明显地表现出对某些理论的冷嘲热讽和不屑一顾。

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《共同基金常识》共同基金值得拥有吗?

博格关于成本的讨论让我们把更多目光放在基金费率上。作为普通投资者,如果不是仔细检验过不同费率对长期回报的影响,我们很容易把0.8%和0.03%费率的基金当做同一个物种。但最具启发性的仍然是关于共同基金行业的分析。博格告诉我们,共同基金并没有看上去那么美好,尤其是考虑到他们高昂的成本,想要长期从数以千计的基金中找到最优秀的几只几乎是不可能完成的任务,普通投资者们也许可以省了这份心了。

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