Why this persona fits the audience
He is the non-founder UI engineer in a five-person startup with two founders, one backend engineer, one operations lead, and him. He currently works on interface components, fixes, and release support for a very small team that still coordinates most decisions directly.
- Age: 27
- Location: Tokyo, Japan
- Occupation: UI engineer
- Income: ¥8.2M base + stock options
- Education: B.S. Information Science
- Company size: 5
- Years in role: 3
“Every pixel matters; clarity in design leads to clarity in function.”
古賀 大介, 27, is a dedicated UI engineer at a nascent fintech startup, operating entirely remotely from his apartment in Shinjuku, Tokyo. Holding a B.S. in Information Science, he found his niche in front-end development, drawn to the tangible results and problem-solving inherent in building user interfaces. His current role is pivotal yet demanding: as the sole UI engineer in a lean, five-person team, he is responsible for the entire user-facing aspect of the product. This includes architecting and implementing new interface components, meticulously debugging issues, and providing crucial support during product releases. The startup's small size fosters a highly collaborative environment where decisions are often made through direct, frequent communication with the two founders and the backend engineer, a dynamic 大介 navigates with his characteristic discipline and focus on quality. His income of ¥8.2M base, supplemented by stock options, reflects his critical contribution and the high-stakes nature of startup equity. He is driven by a deep-seated value for quality and continuous improvement, constantly seeking ways to refine his craft and the product's user experience. Outside of work, 大介 finds solace and inspiration in anime, the ritual of brewing and tasting specialty coffee, and long, contemplative walks through Tokyo's diverse districts, often with his camera in hand. He is saving diligently, viewing his stock options as a long-term investment in the company's success and his own financial future. His approach to work is methodical, prioritizing clarity and robust solutions, a philosophy that extends to his personal life where he values structure and thoughtful engagement.
Background & daily life
A day in their life
大介's weekday begins around 8:30 AM with a pour-over coffee and a quick scan of overnight Slack messages and JIRA tickets. He dedicates the morning to focused coding, tackling UI component development or complex bug fixes. Lunch is a simple bento box eaten at his desk while watching a YouTube tutorial. The afternoon often involves a brief sync with the founders to discuss priorities, followed by more coding, code reviews, and preparing for the next release. He might take a short walk around his neighborhood to clear his head before dinner. Evenings are for personal projects, anime, or catching up on tech news.
Lifestyle
大介 lives in a shared apartment in Shinjuku, Tokyo, sharing expenses with two roommates. His routine is structured, prioritizing work and personal projects. He enjoys quiet evenings, often spent watching anime or reading technical blogs. Weekends are for exploring new coffee shops, taking long walks through different Tokyo neighborhoods with his camera, or occasionally visiting an arcade. He's mindful of his finances, saving a portion of his income and investing in stock options from his company. Socially, he's more of an introvert, preferring deep conversations with a few close friends over large gatherings.
Work life
As the sole UI engineer in a five-person remote fintech startup, 大介 shoulders significant responsibility. His days are consumed by crafting and refining interface components, meticulously fixing bugs reported by the small user base, and ensuring smooth releases. He collaborates closely with the two founders and the backend engineer, often in quick, ad-hoc video calls to resolve issues or discuss design decisions. The team's small size means direct communication is key, and he's constantly balancing feature development with critical maintenance, all while working with a lean codebase and limited resources.
Relationships
大介 is close with his parents and younger sister, with whom he speaks weekly. His social circle is small but tight-knit, consisting of a few college friends he meets up with occasionally. Within the startup, he has a professional but friendly rapport with the founders and the backend engineer, respecting their technical expertise and vision.
How they decide
大介 is a cautious and research-driven decision-maker, especially concerning technical implementation. He thoroughly evaluates options, considers potential long-term implications, and seeks clarity before committing. For UI/UX, he relies on established best practices and user feedback, but in a small team, he also defers to the founders' strategic direction after presenting his technical assessment.
How they sound
Speaks in a measured, calm tone with clear enunciation. Avoids slang and overly casual language, even with colleagues. His sentences are well-structured, reflecting his analytical nature. He tends to pause to consider his words carefully, especially when explaining technical concepts. He rarely raises his voice and maintains a professional demeanor.
Personality traits
- detail-oriented
- reserved
- self-motivated
- perfectionistic
- analytical
- methodical
- observant
- diligent
Goals
- Become a senior UI engineer with architectural responsibilities
- Contribute to a successful product launch that gains significant traction
- Achieve financial independence through savings and stock options
- Maintain a healthy work-life balance without sacrificing quality
- Develop a personal photography portfolio
Problems & frictions
- Balancing urgent bug fixes with planned feature development
- Limited design resources and feedback loops in a small team
- Technical debt accumulation due to rapid development cycles
- Maintaining focus and motivation in a fully remote environment
- Ensuring consistent UI/UX quality across a rapidly evolving product
Values
- quality
- discipline
- clarity
- continuous improvement
- simplicity
Interests
- front-end engineering
- anime
- coffee
- walks
- photography
Media habits
- Reddit (r/frontend, r/reactjs)
- Twitter (following tech influencers)
- YouTube (coding tutorials, anime reviews)
- NHK (news)