Talk with Technical Product Managers (Mercari TPMs, @ akis, @ yuu, @ Suwen) – What It’s Like to Work as TPM at Mercari

This interview is part of a series of interviews where we talk with Technical Product Managers (TPMs) working in the Mercari Group. In this edition we meet Aki Saarinen(@akis), Yuma Kanai(@yuu), and Suwen Weng(@Suwen), who share their experiences, learnings, and outlook for the future as TPMs.

Featured in this article


  • Yuma Kanai (@yuu)

    After completing my master’s degree, I started my career at Mercari as a new graduate. My major in graduate school was mathematics. After joining the company, I experienced the data science team and then I joined the search team as a TPM. I won the MVP of Mercari JP in the first half of 2021. Currently, I continue to lead the search area.

  • Suwen Weng (@Suwen)

    Started the career as a software engineer in a world leading oil service company. I then worked as Product Manager in a Japanese apparel company to build order and inventory management systems. I joined Mercari TPM team in March, 2021, currently working for JP transaction and master products in Camp-4.

  • Aki Saarinen (@akis)

    Discovered programming at the age of 8, and has aspired to create amazing products ever since. After working at a number of startups, joined Mercari in October 2019. Currently leads personalization-related development as PM.


What do you think of Mercari?

@akis: Let’s start by talking about the products we are building. What do you think works well in Mercari’s products?

@yuu: We, Mercari, see ourselves as a market which creates new value, and I do believe that’s exactly what we are. Sellers can sell anything and buyers can also buy anything on our platform at affordable prices—this is what we aim to continue offering. And the great thing for me is that the direction the company is heading in and how I believe Mercari should be are completely aligned. This gives me motivation and makes it worthwhile to work at Mercari.

Yuma Kanai(@yuu)

@akis: Where do you see room for improvement?

@yuu: I think there is potential for improvement in every area. I myself also use Mercari as an end user and find things which can be improved. Especially in the area of matching, such as the search engine and recommendation engine, we still have a lot of things to work on in order to offer our customers even better service. I see that there is huge potential, and we are working hard everyday to enhance our functions.

@akis: How about you, @Suwen?

@Suwen: The first thing that comes to my mind is the content. We need good content to attract customers to Mercari. I think that customers sometimes have difficulties searching for exactly what they want. For example, I was trying to search for a YAMAHA piano, but it was difficult to find what I was looking for, and I had to try different keywords. Having to refine search conditions is troublesome for users, so I’m glad @yuu is working on this already.

Mercari’s culture, work environment, and people

@akis: What is the most exciting part of your job as a PM at Mercari?

@Suwen: I enjoy the open environment at Mercari. Before I joined the company, I was asked at the interviews what I think about Mercari’s values. To be honest, I didn’t have true alignment yet back then, but after I joined I really liked our values, particularly All for One and Openness. I think that the reasons decisions are made, and why those decisions are required, are openly shared to anyone at Mercari. This openness and respect for the employees really impressed me and makes me very happy to work here. Also at Mercari, I feel that I can work closely with engineers and have a chance to discuss technology-related matters with them, so it is great for me, too.

Suwen Weng(@Suwen)

@akis: For the “openness” you mentioned, do you have any examples? What kind of things made you feel you have open communication?

@Suwen: I think a good example would be the way we handle the situation when an incident occurs. When an issue is identified, it is quickly shared in the company’s Slack channel. Then we have several meetings where the management discusses how to handle it and what we need to do. Every discussion is shared in the channel as well as the meeting minutes. I find those follow-up activities, the reasons behind them, and the priorities they set really helpful and impressive.

@akis: Any other examples?

Aki Saarinen(@akis)

@Suwen: Mercari has regular meetings called “All Hands”, such as company-wide All Hands and Product All Hands. The Q&A session is always a very interesting part of the meeting. Any member can openly ask questions regarding the organization, priorities, and employee benefits—this is quite special. I’ve never experienced this kind of communication in other companies, so this is another aspect of Mercari that demonstrates the value of “openness” to me.

@yuu: I am grateful for Mercari’s openness and the atmosphere that lets us talk about anything. For example, @akis is my boss, but he always listens to me when I have a different opinion to his, and asks me why I think so. I really appreciate that we are able to exchange opinions and have an equal discussion. I believe we have a positive environment at Mercari where anyone can speak out about what they think is right, regardless of their positions.

Also, any employee can share their ideas for improvement in the Slack channels, and we actively discuss how we can make our products better. I think it’s great that we all work together to improve Mercari.

@akis: I also think that openness is a big part of the reason Mercari has been able to build good teams, hence good products.

What it’s like to work as PM at Mercari

@akis: What kind of skills are useful in PM work at Mercari?

@Suwen: For business foundation on the backend side, I think strategic planning is one of the important skills. Mercari started as a startup company with a very simple workflow, but through the years we are accumulating more and more technical debt and the system is getting more complex. So in my current role, I need to renew and refine our backend business foundation system, but this kind of work cannot be done in a quarter or even a year. Therefore, an important skill is to be able to find/create a strategy and resolve arising issues. At the same time, I see a lot of data-driven decision making is done in Mercari’s projects, so experience in data analysis will be also very useful here. I’ll leave the rest to @yuu.

@yuu: Firstly, it is very important for a PM to have passion for making Mercari better. What I particularly find interesting at Mercari is that each PM has a different strength and background. For example, some used to work on the backend side as an engineer, while others are good at UX research. Among this diverse range of talent, I think that being a heavy user of Mercari myself helps me understand what the customers think about our products. Another thing is data; I studied math in university and have knowledge of statistics, so I can analyze data with confidence. When some data is provided to you and things don’t look as they should, you can question and check the accuracy of the data if you know how to handle it. I feel this skill is very useful at Mercari.

@akis: How about the other side? What is the most difficult part of the PM job?

@yuu: At Mercari, we do a lot of experiments; we make hypotheses and carry out AB tests to verify them. To be honest, the results are unsuccessful most of the time. It’s very challenging because we will not always get positive results even though we have discussions with engineers over and over again to improve our products. However, I enjoy it even when things don’t go so well. Of course, I’m very happy when I make a hypothesis and I can prove it. But even when it’s not successful, that makes me realize that I am not understanding the customers’ needs thoroughly and it gives me an opportunity to better learn what the customers want.

@Suwen: I totally agree with @yuu. I think the difficult part is usually the most fun part. I had a similar experience in my area, which is the backend side. I face many changes on a daily basis, and I think it is one of the challenging things at Mercari. Since so many changes happen here very quickly, making a product roadmap can be difficult. But in another sense, it’s interesting that everyone in the team can propose something and turn their ideas into reality.

@akis: As PMs, we need to provide something our customers and the world want. How do you understand what customers want and how do you prioritize it?

@yuu: I think one advantage for me is that I use Mercari extensively as an end user so I can see things from the customers’ point of view. Also, we analyze customer behavior to understand what is happening on our platform and how to serve our customers better. Mercari has an internal reference called “Voice of Customers” in which customers share their requests and ideas for their ideal products/services, so I make sure to check it as well as the users’ actual voices on social media. What’s important when implementing something is to determine the feasibility and how much benefit there will be in the long term. We always think about how simply and effectively we can achieve positive performance.

@Suwen: I think the most important thing for PMs is to try out and experiment with different things in our real lives. You can learn different things even in the same business, so understanding of customers’ needs should come from our daily lives. Similar to what @yuu said, I think the first source would be the Voice of Customers. I looked into the past one year of data to see complaints and reviews for transactions, which helped me list up potential improvement areas. Another type of source we should use more is data. For example, the number of transactions each seller/buyer completes is useful when prioritizing the features to work on.

@akis: How do you use data in your work? How is it useful for you?

@yuu: Data is useful when we make a hypothesis, design an experiment to verify it, and evaluate the result of AB testing. The test result is definitely more accurate than our assumptions because we know the actual reaction of the customers when they experience certain things.

@Suwen: Although backend today doesn’t use so much data compared to frontend, our data is widely used by various groups. So you can say we are sort of a provider of data here. At the same time, recently we tried to collect some data in order to judge the future priority of features to work on for a long-term roadmap. For example, there are some comments we often receive regarding transactions, such as “why don’t we support a shopping cart feature?” Naturally, people have different opinions, but we can’t always be sure if the feature should be implemented, so we need to use data to investigate whether this feature is really necessary. This kind of data definitely gives us a clear answer.

How TPMs utilize technology in operation

@akis: Moving onto technology: currently both of your titles at Mercari are TPM (Technical Product Manager), meaning a product manager who works in technology-related areas. Can you share what role technology plays in providing a good experience?

@yuu: Since everything we do at Mercari involves technology, I’ve never really thought about it. Everyone including PMs, analysts, and engineers uses technology to improve the customer experience. In terms of the type of technology our team utilizes, we use various technologies from conventional methods to new ones from the latest reports. We use technology as a tool to solve issues in order to serve our customers better.

@Suwen: For the complex system backend, technology is definitely critical. It exists in every piece of our operation, whether you are a TPM or an engineer. On the backend side, I think there are two types of things we particularly need technology for. One is to learn new trends of transactions, logistics, and purchases in order to determine as a TPM what kind of support we need to provide to the customers in the long term. Another thing technology helps us with is problem solving. There are cases where we receive different requirements for various projects, and we always need technology to solve those kinds of issues. Therefore, technology plays a significant role in setting up a long-term vision/roadmap and solving problems in our daily operations.

@akis: Do you have any story you can tell about an important learning you had as a TPM, either at Mercari or previously in your career? How did you learn something interesting as a TPM?

@Suwen: At the beginning, I was actually working as a C++ software developer for Windows applications. After I decided to change my career, I took some courses to become a PM. I felt that you can get valuable knowledge from online training. Also in my previous job, I joined study sessions with senior PMs to improve our key capabilities as a PM. In order to be able to make a product roadmap, these hands-on training sessions were useful for me. Another type of learning I think is very important and interesting was that, in my previous job, I learned a lot from other members in different divisions about their daily operations. That was very helpful for me to understand what kind of features we needed and were important.

@yuu: Earlier I mentioned the importance of experiments to improve our products. One important learning I had was building a solid system to carry out those experiments. I think it is part of the PM’s job, and it would be a problem if we couldn’t do experiments quickly due to issues with UI and architecture. For example, we decided to change the interface of the platform to offer our customers a better shopping experience, enabling us to do more experiments at the same time. However, that influenced the UX, and we had to be careful not to make it a negative change. After implementing this, we achieved success and brought a positive business impact. What we did right was to develop a system to enable us to work on experiments efficiently.

@akis: Anything else to add about working at Mercari as TPM?

@Suwen: As @yuu mentioned earlier, I think TPMs/PMs at Mercari have very diverse backgrounds. I think Mercari’s TPM/PM team has very good diversity. We have experts in different domains with diverse backgrounds working together to improve Mercari’s products. At the same time, I’m very happy to be working as a PM in this kind of team because I can learn different things from my colleagues. Active collaborations and discussions are very helpful and healthy for the TPM team.

@yuu: One of the many good things about Mercari is that there are various experts everywhere in the TPM team and in the company, and we can help each other beyond our teams and positions.

@akis: Yes, we definitely have a diverse team, and it’s one of the greatest things about Mercari!

Outlook for the future

@akis: What kind of things do you want to do in the future as PM? What kind of things interest you or excite you for the future?

@Suwen: I have many things I want to do. At Mercari, I wish to gain various experiences and involvements in our business foundation; for example, from transaction to logistics, and even B2C and Mercoin as well. Basically, I want to grow my career in the e-commerce vertical. It would be great to be able to try different trends and features. At Mercari, maybe livestreaming shopping? These fun things and others such as POC and innovation projects interest me. And for the longer term, I’m also interested in online education in this kind of industry. I think Japan is still in the growth phase, and changing the current classroom-based education to online-based would be interesting in the future.

@yuu: One of the things I want to achieve at Mercari is to grow the company to the level where we can match tech giants overseas. They are more advanced than us in terms of technology and are able to offer more value to their customers. Although we are not exactly there yet, those companies disclose a lot of technical information, and from that we can learn how they think, what worked/didn’t work for them, and why they’re doing what they’re doing today. We utilize this information and reflect it in our operations at the moment, but someday I would like to catch up with those companies and even compete with them using advanced technology and data.

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