Sina Kallabis

Why this persona fits the audience

At a seed-stage Berlin startup, coordinates two engineers and a designer from a MacBook while testing admin flows in Claude Code and comparing screenshots against Jira tickets. Uses window text, voice notes, and spreadsheets to keep track of product changes across releases.

• Age: 29
• Location: Berlin, Germany
• Occupation: Product manager
• Income: €72,000
• Education: M.A. Media Informatics
• Company size: 15
• Years in role: 3

“The most exciting part is seeing a complex idea take shape, piece by piece, and knowing that our small team is building something that could genuinely make a difference.”

Sina Kallabis, 29, is a Product Manager at a Berlin-based seed-stage startup specializing in AI tools. Holding an M.A. in Media Informatics from Humboldt University, she transitioned into product management after a brief stint as a UX researcher. Her current role places her at the intersection of cutting-edge AI development and practical application, a space she finds both challenging and exhilarating. She manages a lean team of two engineers and a designer, operating primarily from her MacBook. Her days are consumed by the intricate process of refining product features, currently focusing on the admin flows for an AI agent that interacts with user screens. This involves rigorous testing using tools like Claude Code, cross-referencing visual outputs with Jira tickets, and maintaining detailed records of product changes across releases through a combination of window text capture, voice notes, and meticulously organized spreadsheets. Sina is driven by a desire for clarity and efficiency, believing that well-defined processes and constant iteration are key to navigating the volatile startup landscape. She values team coordination highly, recognizing that her team's collective output is greater than the sum of its parts. Her income of €72,000 reflects her experience and the demanding nature of her role in a high-growth sector. While passionate about her work, she consciously carves out time for city biking and exploring Berlin's diverse neighborhoods, viewing these activities as essential for maintaining perspective and preventing burnout. She is pragmatic about her finances, saving diligently but not at the expense of enjoying life's experiences. Her approach to product development is deeply rooted in iterative improvement, constantly seeking ways to enhance user experience and streamline workflows, a philosophy that extends to her personal life and decision-making.

Background & daily life

A day in their life

Sina's typical weekday begins around 7:30 AM with coffee and a quick check of overnight messages. By 9:00 AM, she's at the co-working space, diving into her MacBook. The morning is often filled with stand-ups, reviewing code changes, and testing new features, particularly the admin flows she's currently focused on. She uses Claude Code extensively for development tasks and compares its output against Jira tickets. Lunch is usually a quick affair, often a salad or leftovers eaten at her desk while reviewing user feedback. The afternoon involves more team syncs, planning for the next sprint, and documenting product changes in spreadsheets. She often records quick voice notes to capture ideas or issues as they arise. Her workday typically wraps up around 6:30 PM, after which she heads out for a bike ride or meets friends.

Lifestyle

Sina lives in a bright, minimalist two-bedroom apartment in Prenzlauer Berg, sharing it with a friendly Golden Retriever named Pixel. Her routine is structured but flexible, starting with a strong coffee and a quick scan of industry news before heading to the co-working space. Evenings often involve cycling through the city's parks or meeting friends for Spätis and casual dinners. She's mindful of her finances, saving consistently for future travel and potential investments, but enjoys treating herself to good food and occasional vintage clothing finds. Weekends are for longer bike rides, exploring new neighborhoods, or diving into a good book.

Work life

As a Product Manager at a seed-stage startup, Sina's days are a whirlwind of coordination and problem-solving. She juggles user feedback, technical constraints, and the ambitious vision of the founders, all while managing a small but dedicated team of two engineers and a designer. Her primary tool is a MacBook, where she navigates between Jira, Slack, and various AI development environments. She's currently deep in testing admin flows for their new AI agent feature, meticulously comparing screenshots against Jira tickets and documenting every iteration. The pressure is constant, driven by tight deadlines and the need to demonstrate rapid progress to investors.

Relationships

Sina maintains close ties with her parents and younger brother, who live in a smaller town in Bavaria. Her core social circle consists of a few university friends, now scattered across Europe, with whom she stays in touch via video calls and occasional meetups. At work, she has a strong, collaborative relationship with her engineering and design colleagues, built on mutual respect and shared project goals. Her dog, Pixel, is her most constant companion.

How they decide

Sina approaches decisions with a blend of analytical rigor and pragmatic iteration. She gathers data, consults with her team, and weighs potential outcomes, but isn't afraid to make a calculated choice and then refine it based on real-world feedback. She values clarity and evidence, often using spreadsheets or comparative analyses to structure her thinking, but trusts her intuition when faced with ambiguity.

How they sound

Sina speaks with a clear, measured cadence, often pausing to formulate her thoughts precisely. Her tone is generally professional but approachable, avoiding overly technical jargon unless speaking with engineers. She uses German colloquialisms sparingly and prefers direct, unambiguous language. She tends to avoid hyperbole and focuses on factual descriptions, often prefacing opinions with phrases like 'From my perspective' or 'What I'm seeing is'.