There's no better term to describe this year's version of myself than 'quantum superposition.' In quantum systems, superposition refers to the property where a particle can simultaneously exist in multiple states, like both particle and wave—an uncertain state that possesses both characteristics rather than being confined to a single state. Like a particle in the quantum world, I spent this year struggling within multiple overlapping states simultaneously, and I'd evaluate it as a year of hard-fought battles within that complexity.
With three identities—software engineer, undergraduate student who hasn't yet graduated, and military personnel serving as an industrial technical worker—I found myself in ambiguous situations multiple times. In the second half of the year, after completing my military service and returning to school after a 3-year break, I commuted weekly between Seoul and Daejeon, juggling work and studies through a combination of office attendance and remote work.
Looking back through my packed calendar, this year was once again filled with various attempts and busy living within the given time. However, when I reflect on this year, there's a lingering bitterness—perhaps because I felt more stagnation than the sense of achievement I had aimed for. There were certainly good aspects and accomplishments. But retrospectives aren't meant for bragging. Setting aside the desire to write only positive things, I want to write down my honest and straightforward thoughts as I look back on the past year at year's end.
A Brief Look Back: What Did I Do This Year?
In January, I moved from Benefit Silo, where I had worked for a year, to the Ads Platform Team. Having worked in a silo organization that rapidly developed and experimented with B2C products for a year, I wanted to move to the B2B side and experience a complete cycle of the advertising domain. I requested a transfer to a team that functions as an advertising platform (while the boundaries between teams and silos at Toss have become much more ambiguous than before, they differ in that experimental organizations do 0-to-1 work while more stable products do 1-to-100 optimization). As a foundational team that manages and integrates advertising products across multiple teams rather than deeply handling a single product, I was able to solve more challenging problems and simultaneously expand both technical depth and breadth. The timing was also appropriate—as Toss, which had grown through mobile-based super app strategies, began focusing much more on business users (B2B) this year, I was able to join at the right timing and contribute. Developing Toss Ads allowed me to collaborate with marketing and sales teams at a higher level, understand advertiser needs, and work with great teammates. While there were several other options during the organizational restructuring in the first half, the move to Ads Platform Team was a good decision in many ways.
When I joined in December 2022, Toss had just entered the advertising business, centered around the benefits tab and app tech, and as a latecomer in the advertising industry, had the difficult mission of growing revenue without harming user experience. Internally, we had to convince people that we needed to do 'advertising.' Two years later, with monthly revenue of 140+ billion won and over 200% growth, the advertising domain has grown into a domain responsible for Toss's revenue [1/2]. Personally, it was a time when I could learn AdTech knowledge and concepts related to advertising platforms (e.g., targeting, bidding, budget, creative) and develop interest in this market while optimizing products.
Quantum Superposition
As mentioned in the introduction, I lived in a superposition between three identities in the first half, and geographically between Seoul and Daejeon in the second half. Thinking about why I ended up in such a complex state, two factors come to mind.
First was the desire to use limited time as valuably as possible. With a mind to maximize life's opportunities, I wanted to maintain my identity as an undergraduate student in addition to my role as a working professional, keeping various possibilities open. The more I worked, the more I felt that a graduation certificate didn't mean much to me at this point. If a bigger opportunity were to present itself right now, I would consider taking another leave of absence and delaying graduation. At this young and passionate time, I wanted to explore various possibilities and gain broader experience and learning.
Second was fear of uncertainty. Rather than settling into a single identity in highly uncertain situations, I wanted to maintain both engineer and student identities to create a safety net for future changes. While someone might see me as already building a good career, I had thoughts of wanting to diversify the risks that could occur when choosing a single path.
I expected to leverage the strategically chosen superposition state to create synergy effects and worked to maximize this. I sought to gain broad perspective and insights that would be difficult to obtain when focusing on just one thing. While taking classes in lecture halls, I often reconsidered things I had taken for granted while developing in the office, and gained new insights and refreshment through interactions with students from diverse backgrounds (who were more vibrant and young). I also thought deeply about efficiency, priority setting, and the core goals I should pursue.
Additionally, maintaining this overlapping life required effective time management. For example, during the four hours spent commuting between Seoul and Daejeon each week, I tried to use time efficiently by listening to audiobooks or podcasts while thinking. (As an aside, long-distance travel itself wasn't a big difficulty. Since I enjoy driving, and traveling during non-congested times was actually less burdensome in terms of time and energy than commuting within Seoul via public transportation. Thanks to this, my living radius expanded to 150km, which might serve as preparation for a wider activity radius when I'm in the US later.)
However, this overlapping life brought confusion and exhaustion. Just as quantum superposition collapses into a single state when observed, I too had to choose one among multiple roles, but this process didn't work in my favor. At work, I couldn't devote 100% of my resources to tasks or achieve overperformance, and at school, I often neglected classes due to work or started exam preparation just the day before. While I had decided to return to school with the mindset of 'obtaining graduation requirements' since I didn't value grades highly, and wanted to continue my current work, I realized that juggling itself wasn't true focus. In the end, while I somehow managed to finish a semester, I didn't achieve the results I expected in either area, leaving regret in my heart.
Moreover, the life of traveling between Seoul and Daejeon brought many constraints to relationships and lifestyle patterns. While I had internally looked forward to returning to school after 4 years, reminiscing about college memories while working, I felt a sense of emptiness on campus, as if I was merely attending classes briefly while juggling studies and work. My connections in Daejeon had faded during 4 years of Seoul life, and the tight schedule of about 3 days per week in Daejeon was far from sufficient to build new relationships with good people. This lifestyle pattern added to loneliness, and I ended the year as if escaping when I emptied my Daejeon room after December finals and returned to Seoul.
Gary Keller says in his book 'The ONE Thing' that the key is focusing on the one most important thing rather than trying to do multiple things well simultaneously. He argues that multitasking reduces efficiency and disperses energy, and that people who achieve the best results always focus on just one thing at a time. This year was when I felt this point more acutely than ever. Going forward, instead of overlapping identities, I want to focus on what's most important to me and move toward achieving true results and satisfaction. While this year's experience was certainly a valuable learning opportunity, it's now time to establish a simpler and clearer life direction.
On Work
Domain Knowledge & FE
As an engineer aiming for entrepreneurship, I've always had an ongoing dilemma: Should I build deep technical capabilities as a specialized engineer, or should I contribute broadly as a Product Engineer with a wide perspective understanding product planning, design, development, and operations? This dilemma stems from subtle differences between current and future goals. I decided to do frontend development leveraging my aptitude and interest in technology and art, and while I really enjoy this work, I wanted to fill in product-level and domain knowledge if I ultimately want to become someone who does business. If I had wanted to extremely leverage the former, I would have chosen to be a UX Engineer who could implement in-house design system libraries at the UI level and work more closely with interaction designers (this was one of the organizational transfer options in January), but I still wanted to handle and grow products, so I chose to work as a Frontend Developer on a team where I could actually touch and grow products.
However, Frontend Engineers find it harder to acquire deep domain knowledge compared to Backend Engineers and Data Engineers. Due to the nature of the role focusing on user experience and interfaces, there's a trap of not thinking deeply about domain knowledge when focusing on and solving related problems. This connects to a debate that occurred on Twitter: 'Why are there more CTOs with Backend developer backgrounds?' There's a clear difference in what FE and BE each focus on. Unlike BE, which handles data processing, business logic, system design, and other areas directly related to domain knowledge, focusing on scalability, reliability, and availability while drawing the big picture, FE designs systems with more attention to UI/UX design, performance, and accessibility based on user-centric thinking, requiring technical expertise in user experience rather than depth of domain knowledge. So this isn't about arguing superiority between job roles based on whether they handle domain knowledge deeply or not. It's like the difference between macroeconomics and microeconomics. And furthermore, FE can't really acquire domain knowledge. Recognizing this tendency, one must broaden domain understanding through continuous communication and learning with DAs or PO/PMs while providing insights at higher dimensions.
As I have been doing, I want to more consciously check product metrics and fill in domain knowledge going forward. And as a product-level engineer, I want to consciously practice systematic thinking and drawing the big picture while considering my direction at upcoming crossroads. I hope to develop a balanced perspective that deepens technically while understanding products and business overall.
— (2025.01.05) I personally prefer to be called a Product Engineer or Interaction Developer rather than Frontend Developer.
AI
Also, the cause that brought the most contemplation and change related to 'work' this year was probably AI.
This year, AI's development speed was faster than ever before. As someone who has used ChatGPT extensively in both academics and work, benefiting greatly from it, the speed of results is frightening. Various AI-powered services are emerging, and predictions suggest AGI achievement isn't far away. Amid these changes, I thought about expanding scope as follows:
- Frontend Developer & AI: How will the role of 'frontend developer' change and to what extent can it be replaced?
- Software Engineer & AI: What will 'developers' do?
- Human & AI: Will there be work left for 'humans'?
It was a year when I asked myself many fundamental questions about the future AI will bring, human roles, and the essence of labor.
Honestly, I'm not optimistic about the development ecosystem that AI will change. I think it will bring disruptive changes not just to developers but across industries. Some treat AI like past no-code tools—merely as tools to improve developer productivity—but I'm very wary of such perspectives. Arguments like "We've always found answers and will be fine" seem like excessive optimism that underestimates AI's development speed.
AI has the potential to bring massive paradigm shifts beyond mere technological progress. Like the early smartphone adoption period, this means an era where only those who appropriately prepare according to trends can achieve great results. Missing the wave of change carries great risk of falling behind. For example, devices like Rabbit R1 and Humane (though evaluated as failures, I think they were ahead of their time) showed that we need to fundamentally rethink AI interfaces and interaction methods. Beyond simple on-screen design, being able to conceive and propose interfaces with various modalities might become the new normal for client-side interface development.
The past year was a time of deep contemplation and preparation for these changes, thinking intensively. However, now it's time to move beyond simple preparation to create concrete execution plans and actions. I resolve to make next year one where I clarify my unique role and direction within this massive flow and put it into practice.
Fragmented Thoughts
- Meeting with startup CEOs establishing US-based corporations or targeting the US market over coffee, I felt that America is truly a different dimension in terms of opportunity size and speed. Small beginnings can lead to global-scale results with tremendous upside. It's easier to secure possibilities and resources to realize visions. I want to more actively seek opportunities to advance to the US. The chaotic domestic situation strengthened these thoughts. I originally planned to travel to New York from Christmas to New Year's to directly experience and interact with locals, but couldn't go due to personal circumstances. I should prepare step by step and challenge at the right time.
- In the second half, I spent much time studying investing. I might have spent more time on this than school studies. The trigger was losing big money due to greed after making lucky profits during the fluctuations a few weeks before the US election. While I don't have greed for wealth (I believe wealth is not a goal but something that naturally follows living diligently), the momentary big loss shook my heart. With the thought of recovering more than the principal, I earnestly studied macro trends, added various chart indicators, and explored in depth. Through losing much, earning some, I learned many things as a beginner investor—how to read charts, macro situations and market flows, principles of derivatives, and even human psychology—by researching myself. It might sound funny, but I felt like I learned several truths of life through the process of investing with emotional ups and downs. The charm and appeal of finance seems to be that learned knowledge can be directly connected to financial rewards.
- But I think I was a bit too immersed. My greatest asset is myself, so let me invest in myself.
- If I were to work in a domain other than advertising? The two fields I'm most interested in currently are finance and healthcare. When I eventually want to solve world problems I define myself (=entrepreneurship), I think I'll look for problems in these two domains.
- Finance: A domain where my interest naturally increased through heavy stock/crypto trading in the second half. The finance I'm talking about includes crypto finance beyond traditional finance, and while I'm not studying as intensively as at my previous job, I'm still watching related technology and market trends.
- Healthcare: Through acquaintances working in medical fields, I've long known that many legacy systems still exist in the healthcare industry. Traditional medical systems seemed to have much room for improvement through digital & AI transformation. I've worked on several healthcare projects in the past and am currently working on new related projects.
- I seem to have 'cognitive busyness.' Too many thoughts make it hard to focus on one thing. With high goals on top of this, I become harsh on myself and often get tired faster than expected, overwhelmed by it all. When consciously focusing on one thing, let me reduce transitions and divergence to other thoughts. Next year I should cultivate habits of efficiently immersing in one task.
- This year I went to Sydney in February, Hong Kong in April, and Turkey in July. Next year, after finishing my Sapporo trip in January, I plan to focus more on completing my studies in the first half. Travel probably won't be possible until the second half. For my next trip, rather than simple tourism, I want to set a special theme (e.g., Silicon Valley IT company tour, Japanese architecture trip, volunteering/projects in developing countries) for deeper experiences.
- Around this summer, thanks to a close junior and former colleague, I worked out almost 5 days a week near Gangnam Station after work, building muscle and becoming much healthier. Though I stopped exercising after returning to school in fall and deflated like a rubber balloon again... Since I felt the joy of fitness for the first time in my life, I should continue steadily going forward.
Looking Ahead to 2025
I expect next year to be a time when these overlapping states are somewhat resolved and various constraints and uncertainties are lifted for me. Since the overlapping states that existed until this year have ended, I hope next year can be a time to focus on the one most important thing and make an impact, rather than trying to do multiple things well simultaneously.