Chinese Version
08-20-2021，Friday, Cloudy and Sunny
Today, while chatting with Vicki, she showed me her harvest of big colorful tomatoes and her multitude of eggplants hanging on one plant. I asked how did she become such a skillful farmer. Turns out, she had a high IQ worker who took care of the crops for her, and she just enjoyed picking the fruits and vegetables. Indeed, she is a farmer who sits back to enjoy the harvests of others’ labor. But that wasn’t always the case, thinking back to the time when we were farmers in the software coding fields, she could not sit back but instead had to roll her sleeves.
I recalled the first project I worked on with Vicki in eBay’s software coding fields: Introducing 5th-Level leaf category to eBay’s existing 4th-level leaf category tree (“5th Category” in short).
The eBay categories sort and group eBay’s tremendous goods from many casual and professional sellers into different relevant clusters. The eBay categories to eBay goods is a bit like the skeleton to the human body, as the eBay categories are the internal navigation channels for storing and retrieving eBay goods in a quick way.
eBay category is a critical aspect of selling goods on eBay and eBay’s business, because eBay organizes selling goods into different categories intend to help buyers to find things to buy easily. Therefore, eBay sellers want to pick the right category to sell theirs goods quickly. Also from a business standpoint, eBay wants to analyze the eBay transactions in clusters to forecast selling trends accurately in different categories.
Jim, my boss, was the technical development manager of this project, Meredith was the product manager, Vicki was the software development leader (and the real product manager), and Jeff and I were the main developers for this project. It was a huge development project.
The Critical Role of eBay Category
Much of eBay’s internal business logic was configured based on eBay’s category structure. In 2001, eBay’s US official website had more than ten top categories, including real estate categories (ID verification required, third-party escrow provided), motors categories (many models, third-party escrow provided, it is a different web site from eBay US), and antique collections, etc. There can also be four levels of subcategories under each top category.
The major revenue of the eBay website comes from the listing fee. eBay sellers pay for storing each good on the eBay system. Different types of category may have different listing fees, for example, the listing fee for each car in the motors category is 100 US dollars.
eBay also has a hidden category for adults called “Everything Else”. Adult users had to log in to search for this category. Back then, we jokingly called this category “eBay’s Dark Side.” Looking back today, I think the low-key approach to the adult category at that time was one of eBay’s thoughtful approach, which showed that eBay was aiming to become a respectable high-tech company.
Many technical designs of eBay’s online goods were also closely related to eBay category structure. For instance, the core technology to distribute eBay goods into different databases, instead of a single one database, was based on eBay’s category structure. I remember that there were 11 databases for storing information of eBay’s online goods, including from category host 1 to category host 9 and 1 default category host (CatHost0-CatHost9, 1 DefaultCatHost). This design was completed before 2000. Vicki once explained to me: “This design made it impossible for 11 database hosts to collapse at the same time, so there are always some database hosts that can support the buyers to browse eBay goods online and allow the sellers to list new goods in some categories. Therefore, eBay’s website will not be completely paralyzed due to database problems.” In 2012, the second year after I worked at Paypal, Paypal started to consider storing user data in multiple distributed database hosts to prevent the entire system from becoming paralyzed, which just goes to show that eBay’s database design was more than ten years ahead of Paypal’s database design.
A very special project
Jim, sitting next to me, mentioned the importance of introducing the 5th level leaf category into eBay category a few times before it became a real project. According to Jim, 5th level leaf category was needed by the collectible top category only, other top categories did not care this feature at all. Extending to a 5th level leaf category in eBay category tree would affect almost the entire eBay system and management was afraid that such a change might cause unseeing problems to the already very complicated eBay system. So it was difficult to find a suitable product manager to start this project.
I went to the first floor with Jim to meet Meredith, the potential product manager of the “5th Category” project. She dressed very casually and spoke very friendlily. From the conversation I learnt that Meredith was the owner of eBay US collectible category, and she had several assistants. She and her assistants were responsible for adding and changing categories under the collectible top category according to the needs of sellers and of eBay’s internal business, in order to ease the search and sale of collectible goods on eBay’s website and to facilitate business analysis of after-sales data. She was not really a product manager, so I was curious how Meredith would compose the product requirements for this project.
Later, Meredith really became the product manager for the “5th Category” project. At the first project discussion meeting of “5th Category”, Meredith said: “eBay US has more than 10 top categories and the owner of each top category is just like me, they only care about how to easily and smoothly add the 5th level leaf category to the existing 4th level leaf category from the perspective of the administrator. Regarding the specific design requirements and technical implementations that may be involved in adding the 5th level leaf category to eBay category, I am willing to follow the suggestions of developers.”
I heard that this was a very technical project, and Vicki was the real product manager.
Vicki, the Product Manager
“Introducing 5th-Level leaf category to eBay’s 4th-level category tree” was similar to widening the water pipes of all the rooms in a building, the implementation details were cumbersome, and the construction designer must be familiar with the internal structure of the building. So Vicki seemed to be the right candidate.
“5th category” project required all front end pages and behind the scenes business logic that refer to eBay categories to be upgraded and updated, including eBay’s search domain and list domain, two completely independent services. The development managers of those two services discussed with Vicki about their concerns on technical design and their hopes that the design could optimize the implementation.
Vicki told the two managers: “We will modify the core data structure of eBay category to handle 5th-level. If your applications could dynamically handle the eBay category structure in your domain, then your back-end changes might not be big, but the user facing pages probably needed more changes, as the UI real estate would be expanding.”
Those two managers, middle-aged, were very satisfied with Vicki’s answer.
Jeff and I were both newbies who had just joined eBay and did not have a full picture of the eBay categories. According to Vicki’s design , we changed the intricate software code related to the eBay categories in eBay’s core software system. Jeff and I were both serious and hardworking people, but a few hours after this product was launched on the eBay website, we were notified: “’5th Category’ project brought system memory leaks.” Memory Leaks are recognized by C++ language software developers as a fatal point, because memory leaks may cause the system to crash.
Vicki quickly found Josh, a geek for the production website, who went to live debug to triage this memory leaking. Josh quickly found the line of code that caused the system memory leak and shared the details on the “Netscape Instant Message”. Jeff and I worked together overnight to modify the code that caused the memory leak. That was the first time I saw Josh. I thought Josh, who was short with a long beard and dressed very casually, seemed to be deliberately pretending to be an old guy, which qualified him as the “old naughty boy” in Jin Yong’s novels in my memory.
“5th Category” was a very large development project, which only introduced a single memory leak, so this was a very successful project. Meredith, the theoretical product manager, specially organized a celebration party for the developers and gave each person a customized clock.
Snippets of eBay Culture
1. In 2001, eBay seemed like to gift clocks or watches to employees.
In 2001, Lynn, the product development VP, gave us a watch with an eBay logo as a new year gift. I remembered the watch has two styles: men and women, it was very pretty. After I got the watch, I joked with my colleagues: “We were in a rush to deliver products every day. Now Lynn gave everyone a watch to further enhance our sense of being in a timely manner.”
This is the fifth anniversary souvenir eBay gave to the employees. Photoed by Vicki: another clock
2. eBay 5th level category structure and eBay management structure
In 2001, eBay’s management structure was CEO – VP – Manager – developer, a total of four levels. One day we talked about the “Extending eBay category structure to the 5th level”. Sonya joked: “The company’s management structure is only four levels, but the eBay category needs 5th level. It seemed that eBay goods were more complex than people!”
Therefore, the 5th category had another meaning among developers who were familiar with the eBay category. A few years later, while the number of developers increased sharply, the company’s management structure also expanded quickly. A senior developer once commented: “In terms of personnel structure, we were already under the 5th category, and people are really more complex than eBay goods.”
Little Episodes
1. The happy growing eggplant and the harvested large tomato shared by Vicki, the laid back farmer:
2. Vicki’s tomatoes had been dry in the middle. She thought it was caused by the insects initially. Later, her friend, an expert, told her it was calcium deficiency and needed to add calcium fertilizer. Vicki smashed her calcium tablets to mix with water and feed her tomato plants. After this, her tomato grew big and full as shown above.
3. 2021-08-20, eBay category structure on search front page:
Antiques have 5th-Level leaf category
eBay’s adult category：
