Manager or player? Conversation with @deme, EM of the Mercari US backend team #WeMakeMercari

In the #WeMakeMercari series, we introduce you to some of the remarkable members of the company. In this episode, we have Naoki Shimizu (@deme), the engineering manager of the backend team in Mercari US.

The three pillars of the Mercari Group are Mercari JP, Merpay, and Mercari US. The latter is in charge of developing Mercari’s business and service with a focus on the US market. Some members of Mercari JP are transferred to Mercari US to help with this mission.

Naturally, once crossing borders the languages, cultures, and markets are different. Despite being the same Mercari app, what were your concerns when you decided to transfer to Mercari US? What are the differences in management between Japan and the US? We talked with @deme about these and other topics, discovering more about his motivation and future ambition when taking this opportunity.

Disclaimer: This interview is a translation of an interview conducted in Japanese before working from home started. All Mercari employees are currently working from home as stated in our CEO statement in regards to the novel coronavirus.

In this interview


  • Profile
    Naoki Shimizu (@deme)

    Shimizu joined Mercari in May 2016 and worked as a software engineer in charge of developing the US version of the Mercari app. In January 2017 he worked on development of new features, microservices, and rebranding the app for the US market, and in May 2018 he became engineering manager of the backend team working also on engineer recruiting and team management and as leader of different projects. In January 2019, he officially moved to Mercari’s US office. His nickname is @deme.


The road to becoming engineering manager of the backend team

ーIt’s been about six months since you officially moved to Mercari US. Were you always interested in working in the US office?

Yes, of course. Actually, I joined Mercari because I wanted to create a global product. Initially, I was in the US app development team based in the Tokyo office, and then I was seconded to the US for a while. Finally, in January 2019, I was officially transferred to Mercari’s US office.

ーNow you are the engineering manager of the backend team. Did you have the same position when you were seconded to the US office?

No. In the beginning, I was a software engineer. In fact, in 2017 we only had about 10 engineers in the US office so we didn’t need a manager for that small of a scale. At that time, the Customer Support members were hired in the US, and most of the product development team was sent from Japan. It was a period of adapting the Mercari JP app for the US market.

Showing what the Mercari US app looks like

We experienced a big change in 2018 when John (John Lagerling) joined as CEO and Mok (Mok Oh) as CTO. From there, we worked on rebranding and localizing the Mercari app for the US market, revamping our development system, and starting to hire locally. At the same time, the development team split into a client, ML, backend, etc. it was then that Mok assigned me as engineering manager of the backend team.

ーWhat a casual appointment!

Yes! Now that I think about it, it was such a casual way to accept an offer. (laughs)

Juggling management and project leadership

ーIn Mercari, manager is not considered a position but a role. Management of people is the main focus of managers at Mercari JP, but how is it in Mercari US?

In Mercari US, the management of people is a core task as well. The difference is that being an EM also requires a commitment to the project.

ーSo it’s a role similar to project leader?

Yes, that’s right. Mercari US is still a small-scale organization, so I am doing people management for the backend team and I am also a cross-functional project leader.

The difficult part was balancing the success of projects and management of the backend team because the two parties don’t necessarily have the same interests. Also, because I used to be a player, I had more fun doing things myself so I couldn’t help continuing to do it. But that was actually a blocker for the project and also the team, so there were times where it failed as a result. From that experience, I learned that delegating work is a fundamental part of management.

@deme (center) working on development

ーI understand what you mean about “having fun doing it yourself”.

Sometimes it’s faster if I do it myself but the team cannot grow that way. Even if I hesitate a bit, I need to trust my team and delegate the work to them. For example, the backend is involved in almost every project so I assign a member with the right skill set to work on what I cannot keep up with. However, as EM I am still responsible for the recovery part.

Also, in the US job roles are well defined, with detailed job responsibilities written as terms and conditions of employment. Each member has a high degree of responsibility in their own area, so when I assign a job I try to clearly communicate the job I am assigning and the expected outcome. Of course, that doesn’t mean that we can do everything perfectly, so it’s important to help each other outside of our own responsibilities. I carefully assess the situation of each member and give feedback as necessary, communicating in a respectful way.

As a result, the projects I was in charge of achieved the company-wide KR in the September–December quarter of 2019. I am happy to say that the backend team members were able to achieve their goals in the projects they participated in. In my case, I was able to make a big impact as part of the backend team and also in the projects I was directly responsible for. This was the moment when I felt I was starting to successfully balance management and being a project leader.

The reason behind becoming EM

To tell you the truth, I still feel like I want to work as a player. Of course, I am committed to the backend team until they find a new EM, but after that, I would like to go back to software engineering and development.

ーUntil they find a new EM for the backend team? What do you mean?

When it comes to the backend, deep knowledge about the domain and technical leadership are required. Also, because we run a marketplace app, it’s necessary to develop complex features such as delivery and payment. In addition, we also need to work closely with Mercari JP’s SRE and security teams. It’s a highly complex area, so it’s not easy for a new member to become EM right away.

In my case, I had experience working in the Japan office and had a lot of communication with members of Mercari JP. I also had four years of experience working on the development of the Mercari JP app and had knowledge of the domain, so I was able to take the role of EM of the backend team. We started hiring locally in the summer of 2018. Now the members hired at that time are project leaders or mentors of new members.

Group picture of the Mercari US backend team

ーDo you mean that it’s starting to form a big group with the new members hired locally?

Yes, exactly. If it keeps going in this direction, soon we will have someone to replace me. That’s my ambition! It’s difficult to become an EM of the backend team in the US right away, but it is possible to develop talents and promote someone already in the team. Once that is arranged, I would like to move to another position as a player.

Why Mercari US?

ーSo you told me you joined Mercari because you wanted to develop a global product. Honestly speaking, I think other companies are also able to develop global products. Why did you choose Mercari out of all of them?

I think I chose Mercari because I would be able to develop in the US. I like the idea of experiencing product development in unknown territory. Besides, Mercari US is still in a startup phase, so it’s interesting to see how the product and the organization grow.

I understand how difficult it is to succeed with a global product. In the midst of all of this, Mercari US is growing as a product and also as an organization. The backend team is also forming a good cycle and we want to keep going in that direction.

Mercari US has experienced an evolution. Starting as the US version of the Mercari JP app, moving to locally hiring almost all members in leadership positions, to finally becoming a different product and company from Mercari JP. Now Mercari US is no longer considered an extension of Mercari JP, but an independent startup.

However, in order for Mercari to succeed globally both as a product and as an organization, we need Mercari JP and Mercari US to join forces, sharing technology and culture. As one of the few members originally from Mercari JP, I want to contribute to developing strong synergy for this purpose.

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