2025 H2 Retrospect
๐ฐ๐ท: https://junsong.xyz/ko/2025-h2/
This marks my third consecutive year writing a year-end retrospective. If the first half of the year was dedicated to studying CS courses after returning back to the university, the second half was spent traveling across the globe, gathering experiences that were both joyful and enriching. Fortunately, I'm starting to feel much comfortable speaking English while I have friends that I can hit up for lunch in various cities all over the world.
Many moments stand out, but the most memorable was the excitement I felt when landing in Buenos Aires after a 30-hour journey. It was one of those places where Iโd wonder, "Will I ever get to go there in my lifetime?" while always telling myself, "I have to go there someday."
2025 felt like a year of immense growth, though in a very different direction compared to my corporate years in 2023 and 2024. It makes me so excited for whatโs to come. With less than a day left until 2026, Iโm wrapping up my reflections on the second half of this year.
Here's the list of my retrospects for last 2.5 years:
EPF (Ethereum Protocol Fellowship)
I was selected as a fellow of EPF (Ethereum Protocol Fellowship) this year, and I was dedicated to one of the project about Ethereum core development. Thanks to EPF, I've visited France and Argentina which was really cool.
I was first fascinated at Bitcoin and Ethereum when I was in the army. While there were a lot of speculative viewpoint about blockchain, what I delved into was the technical aspect of it. I've simply respected the term "core development", so I switched my major to CS (thanks to my uni, it was so smooth) and my first career had begun at one startup that I could do sort of core developement. As four years passed, my favorite is now Ethereum (there are tons of reasons that I couldn't jot down here), and it was smooth for me to have a goal as an Ethereum core dev. Through the connections Iโve made through EPF, I plan to officially transition my career into becoming an Ethereum core dev in the coming year.
For detailed recap, please check out the articles below:
Jun Song
Ream & lean Ethereum
PQ Workshop @ Cambridge, UK
Since last year, I was part of Ream team that is building things related to lean Ethereum(leanroadmap.org). At H2 this year, we've been making a new client based on Post Quantum cryptography. PQ Workshop was held at last December at Cambridge, UK, and my main goal was demo'ing the very first PQ devnet. I still vividly remember that night at the Jesus College cafe, where we were intensely debugging until the late hours. It all paid off when we successfully demonstrated the interop between different clients.
Since my business trip to Argentina in November, I havenโt been able to dedicate as much time as Iโd hoped due to several overlapping personal commitments. However, starting in January, I plan to find areas where I can contribute and get back onto the track.
2025 Fall Semester - Trade-offs
Since my business trip to Argentina for Devconnect in mid-November was planned well in advance, I intentionally took a step back from my academics this fall. I mostly chose online courses or those with no attendance requirements, starting the semester with the bare minimum of 13 credits.
In the end, my grades were a bit disappointing โ a reminder that "chasing multiple rabbits" is never easy. Despite my background as a foreign language high school graduate, I ended up with a C+ in Spanish Conversation due to some vocabulary-memorizing struggles. In Intro to Computer Networks, I thought I had a solid grasp of the concepts, but the professorโs "creative" exam questions landed me a B+.
On the bright side, I managed to get an A+ in Program Reasoning, thanks to a decent performance on the final. I also cleared my Writing and Leadership courses, which are mandatory for graduation, so Iโll count that as a win.
2026 - Hello, New York!
And now, Iโm about to head out to New York, to complete the KAIST-NYU Minor Program (Minor: Cybersecurity). I chose Cybersecurity because it has a natural synergy with my interest in blockchain and Ethereum, which fall under the broader umbrella of information security. I will stay at least four months (equal to one semester) but it depends on the program called "Academic Training" โ a policy that allows students to gain practical work experience related to their major. My dream is to gain some hands-on experience as an engineer in NYC before returning, though nothing is set in stone yet. I have no idea where Iโll be by next summer!
Fortunately, the staggering cost of living in Brooklyn will be largely covered by the Korea-US Advanced Industry Youth Exchange Scholarship. As part of this, Iโve taken on the ambitious task of researching the adoption trends of blockchain within U.S. institutions and the financial sector. Given the buzz around stablecoins and the Ethereum Foundationโs push for blockchain as a Settlement Layer, it feels like a very timely and relevant topic.
Living in one of the worldโs greatest cities for a few months is incredibly exciting, especially since this will be my first time actually stepping outside a U.S. airport. As someone who loves visiting art museums(modern art in particular) I expect to be a frequent visitor at the MoMA with my NYU ID in hand. Plus, since NYC is a major Web3 hub, Iโm looking forward to connecting with many people in the industry.