Establishing a Career as a Specialist: Breaking Down the New Principal System for Engineers and Product Managers

At Mercari, we have something called the Engineering Ladder, which shares our vision of the ideal Mercari engineer and defines what kind of skills are necessary in their work. The ladder goes into detail about what kind of actions are expected for engineers at each Mercari Grade (MG), which are the employee grade levels that we use internally. It is meant to help engineers get a better understanding of where they are, and what kind of actions and skills they must exhibit to reach the next level.

Engineers are a diverse group of professionals, each holding their own skillset, workstyle, and career path. However, at Mercari specifically, we talk about career paths in the context of two categories: management and individual contributors (also referred to as “specialists”).

For those pursuing a career path in management, their managerial role is made clear in their job title, whether it is Engineering Manager, Manager of Managers, Director, or VP. However, for those building their career as an individual contributor (“IC”), there were no job titles to indicate their career level.

This is why in January 2024, we decided to introduce the title “Principal Engineer” for our highly experienced MG6 engineers. At the same time, there were also active discussions about career ladders for product managers working as ICs, so we decided to introduce the Principal System.

In this article, we spoke to the VP of Architect & Foundation Engineering Motoki Narita (@motokiee), who founded the Principal System, and CPO Takaaki Shinohara (@unryu-in). In our conversation, we get into the purpose behind introducing the Principal System and what they expect from such specialists with high expertise and skills.

Featured in this article


  • Motoki Narita

    Motoki joined Mercari Group as a member of Souzoh, Inc. (now absorbed into Mercari, Inc.) in September 2016. After working on the development of Mercari Atte and launching Mercari Kauru as a new business, he transferred to Mercari in April 2018. He then worked as an Engineering Manager and the Engineering Head of the NewBiz team before transferring to Souzoh in January 2021. After launching Mercari Shops as an Engineering Manager, he returned to Mercari to manage architect teams in such domains as mobile, web, and backend. In January 2024, he assumed the position of VP of Architect & Foundation Engineering at Mercari.


  • Takaaki Shinohara

    After working as a freelance web director, Takaaki joined GREE, Inc. in 2012. He joined BizReach, Inc. in 2014, where he launched a media service for people looking to change jobs. He joined Mercari in September 2017. After serving as Director/Head of CRE, he transferred to Merpay in April 2020, where he headed up the alliance project. He established Souzoh, Inc. after that, in January 2021, where he oversaw PM/BD/CS/QA as Head of Product. In July 2022, Takaaki committed to building a safe and reliable service ecosystem for Mercari Group as Mercari and Merpay’s Vice President of Trust and Safety. In January 2024, he was appointed CPO of Marketplace.


Establishing a new career ladder for ICs

——If I remember correctly, Mercari used to have the title “Principal Engineer,” until around 2018. Why did you decide to bring the title back now, six years later?

@motokiee: Yes, that’s right. I was a big fan of the previous Principal System, and how it presented clear role models for engineers to aspire toward. We brought back this system because we wanted to establish a career path for engineers working as ICs.

Mercari has a clear career ladder for engineers who are interested in management, with titles like Engineering Manager (EM), Manager of Managers (MoM), Director, and VP. However, we did not have similar titles to signify someone’s position among ICs. It was not possible to know which ICs are in senior grades, since members do not have access to other people’s grade levels, and as a result, it was hard to find a role model while working as an engineer at Mercari.

I personally have pursued a career in management, but I felt that our discussions often lacked the viewpoint of ICs. I thought there was a need for our organization to reflect the opinions of our talented specialists more, and that’s another reason why I wanted to bring back the Principal System.

Motoki Narita (@motokiee)

@unryu-in: For product managers, their job is to manage all of the members who are involved in a given project. However, their role can also involve participating in regular 1on1s with people in their report line, evaluation meetings, quarterly business reviews, and retrospectives. These additional tasks require a lot of time and energy, and it can be difficult to maximize their performance as an IC.

Up until now, the career ladder for product managers was also designed with a path focused on management. If you keep moving up the ladder, you will inevitably end up as a manager, ultimately in the role of a Director, which is mainly a people management role. We thought there should be a system or framework for people who want to advance their career as a product manager while focusing more on feature development rather than people management.

I took a look at some documents prepared by @motokiee right around the time when we were starting to review our organization’s systems, and we decided to introduce the Principal System for product managers as well.

@motokiee: In the near future, I think this kind of title for ICs will become necessary for other roles like designers, too. If it works well for product managers, we’re considering expanding the system to other roles as well.

Defining roles and responsibilities: What does an established career look like for ICs?

——What will the Principal System look like for engineers and product managers, respectively? Will there be any differences in how the system is operated between the two roles?

@motokiee: At Mercari, engineers are evaluated based on their grade level, and we give the title of “Principal Engineer” to engineers who are MG6 based on our grade system. And, if they move up to MG7, they will be given the title of “Distinguished Engineer.”

When we were discussing how to operate the system, there were also ideas to appoint members individually to the Principal Engineer role. However, this would involve people’s subjective opinions and make things too complicated, so we decided to follow the grade system that is defined by the company.

@unryu-in: For product managers, you can take a look at the yellow parts of the image below (Graph 1).

(Graph 1)

We’ve added a new portion (labeled “Principal”) to the career path for ICs. Up until now, ICs were mainly MG1 to MG5. If members wanted to move to MG6 or above, they needed to switch career paths to the managerial roles on the right. With the Principal System, we were able to establish a clear path for members who want to reach MG6 or above as an IC.

(Graph 2)

Now, this second graph sorts out the responsibilities of each role, and it shows how ICs are responsible for executing the direction determined by VPs and Directors.

There is a certain amount of people management within the product manager role, just due to the nature of the job. However, for those in the management path, their responsibilities specifically include “organizational management,” which includes everyday 1on1s. On the other hand, the responsibilities of ICs include “creating business KPIs,” which requires stakeholder management. This could also be considered people management, but we differentiate it from the kind of people management included in the management path since they serve different purposes.

Of course, the chart is just a general overview of the differences in each role, and it’s more like a guideline than a rule. For example, there are many instances where ICs are making proposals for mid- to long-term direction and driving this vision forward. It is also not uncommon for people in the management path to move back to an IC role.

What sets this new Principal role apart? The ability to lead and contribute to the business

——I’m curious, what kind of members are in the Principal role now, and how did they get there?

@motokiee: In the engineering organization, engineers who make large contributions to the company and those who demonstrate the top level of skills and creativity have moved up to the higher grade levels and are considered Principal Engineers.

Going forward, I’d like to place more focus on their external communications and support for members’ personal development. Especially with regard to member development, because people’s grade levels are not disclosed to other members, we’ve heard engineers say that it’s hard to know who to aspire to be like or whose career to use as a model for themselves. By introducing the title of Principal Engineer, I think it will make it easier for these members to discover potential role models around them and inspire them to grow.

@unryu-in: With regard to product managers, those who can lead large projects that are significant enough to impact the company roadmap are in the Principal role. Mercari Hallo and Mercari Shops are recent examples. We look for people who can act as the project owner and coordinate projects that span across multiple companies.

——It sounds like those in the Principal role have contributed to Mercari in many different ways so far. Going forward, what kind of things would you like to see from these members?

@motokiee: I would like members in the Principal role to see themselves as leaders of our engineering organization, just like those in the CTO, VP, and Director roles. People might think that the job of engineers in IC roles is just to write code. However, in my view, Principal Engineers go beyond by steering the vision of Mercari’s engineering organization with both their technical and leadership skills.

It’s not an easy task. The role is multifaceted, requiring top-notch engineering skills to achieve technical breakthroughs that others cannot, as well as the strong leadership necessary to solve issues present in our engineering organization. We plan to further define the role and its responsibilities in our Engineering Ladder. In the leadership aspect, we of course also expect our Principal Engineers to develop other talent and share information internally and externally.

@unryu-in: Directors place their focus on mid- to long-term strategies, while those in the Principal role are responsible for the more short-term actions and initiatives to achieve the long-term strategies. Specifically, I expect Principal members to take it upon themselves to enhance our UX and drive forward complex projects that involve stakeholders from multiple companies. With their actions, they can set an example and encourage the people around them to grow and follow suit.

Takaaki Shinohara (@unryu-in)

——Interesting! I’m seeing that being a role model and inspiring others to grow is a big part of the Principal role. Now, since I have you both here, is there anything that you’d like to ask each other?

@unryu-in: Sure. I’m curious, what do you think about having a VP path after the Principal path for ICs? Looking around our industry, I feel that there are many engineers who are in a VP role while still making an impact with their supreme technical skills.

@motokiee: I see the Principal and Distinguished paths to be different from the VP path. Like you mentioned, at startups, you’ll find many CTOs and VPs who are writing code themselves and very much involved in development—which I think is amazing. However, Mercari is no longer a startup, and we have several hundred engineers. With more people, there are more roles and responsibilities expected of management.

It is natural for those with leadership skills to seek out and take on leadership roles. However, up until now, the only clear option that we had available for them was the management path to become a VP. The thing is, though, I actually know a lot of engineers who want to be writing code forever, even when they’re in their 70s. (laughs) They’re not interested in people management, and I think that’s fine! My point is that if someone has the qualities of a good leader, I think it’s a waste to only present them with the management path. They can still be a great leader as an IC.

@unryu-in: I’m not an engineer, but that’s how I view it, too. Come to think of it, for you and me as well, our work and responsibilities tend to change depending on the project or what phase our business is in. I can see a situation where a Principal member switches to a VP role, or vice versa.

Mercari has a culture of change and flexibility, and that’s why it’s especially important for us to regularly review and define the core roles at our company, like we have with the Principal System.

——Lastly, could you tell us what kind of impact that you hope the Principal System (and this new Principal role) will have on Mercari Group?

@unryu-in: We just spent all this time talking about how we are working on defining the Principal role, so this might sound a little contradictory, but I don’t want to place too much emphasis on defining specific roles. Like I said earlier, people’s roles change depending on the project and phase of the business. I want the role to remain flexible and avoid creating a cookie-cutter definition for everyone, but at the same time, we have to put it into words in order for people to know the right evaluation criteria depending on their project or phase.

Right now, we are in a stage where we are thinking of how to achieve the future we are envisioning as soon as possible. We are working on the points that need clarification so that people have a better understanding of their role, but with that being said, just because someone is in a Principal role, I don’t think they need to limit themselves to what is written in our definition. It is meant to just serve as a guidepost.

@motokiee: First and foremost, I want to establish a career path for ICs. Then, I’d like to see these members playing a role in creating the future of Mercari, together with other leaders like CTOs and VPs.

In order to do so, I will work on reflecting their voices and opinions to the Engineering Roadmap as well as Mercari Group’s mid- to long-term roadmap. We need to constantly be looking two to three years into the future, and thinking about how we can continue expanding and updating our technical capabilities. By doing this, I’d like to set the engineering organization up so that both Principal members and VPs can take lead and help us propel Mercari toward achieving its vision.

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