GROWTH DESIGN
From Zero to Traction
In short — heystack was a social discovery app built around events and locations. It was developed out of the Antler Startup Incubator in Berlin. My brief was to tackle low weekday engagement by design.
Building on extensive user research, competitor benchmarking, and behavioral design models, I introduced a meetup feature that enabled weekday engagement while staying true to the app's location-based DNA.
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OVERVIEW
Connecting People IRL
heystack is a hyperlocal social discovery app built around events and locations. It was developed by an ex-Google and an ex-Revolut engineer and emerged from the early 2023 cohort of the Antler Startup Incubator in Berlin.
The mission of heystack is to converge the benefits of physical events with the ease of online introductions. By identifying those at a shared location, users can connect fearlessly, knowing the interest is mutual.
This promotes real-time interactions while preventing the drawn-out, repetitive messaging loops that often lead to disengagement and eventual ghosting. The idea for heystack stemmed from two key observations about modern social interaction:
Platform Fatigue — Many social platforms for dating or friend-finding become counterproductive due to user overload, leading to repetitive exchanges, dwindling engagement, and ultimately, ghosting.
Social Inhibition — Despite an abundance of offline social opportunities — clubs, festivals, bars — many hesitate to start conversations, deterred by the fear of rejection or judgment.
Despite having validated market fit, the co-founders decided to discontinue the project in early 2024 due to personal circumstances.
DESIGN BRIEF
From Weekend Buzz to Weekday Habit
heystack's utility was largely centered around weekend events — parties, clubs, and nightlife. Yet, for long-term retention, maintaining consistent weekday engagement is essential.
My design brief was defined by one central question:
How can weekday traction be built by design while keeping heystack distinct from Tinder or Bumble and true to its unique event- and location-based value proposition?
User activity peaks on weekends but remains low during the week, leading to two core challenges:
Keeping weekend users engaged throughout the week
Converting potential users outside weekend contexts without drifting into a generic social network
Any solution therefore had to stay anchored in real-world events and places, delivering real value by sparking human connection in shared spaces — leveraging the momentum of being in the same place at the same time.
In response, I focused the design on two strategic objectives:
Encourage regular, habitual app use without diluting the core proposition
Capitalize on real-time, location-specific opportunities to spark interaction between users
PRIMARY RESEARCH
Interviews & Survey on Why People Meet
Since weekday traction was not a simple usability issue that could be solved with a quick UI tweak, it called for some good old primary research into user motivations and behavioral patterns.
To uncover the true drivers, I structured this research into two key phases:
An initial user survey with 55 participants, providing quantitative insights on key engagement factors, social barriers, and app usage behavior
Followed by 10 in-depth user interviews, designed to qualitatively expand on survey findings and provide a deeper understanding of users’ motivations, expectations, and unmet needs
The research helped me better understand why and how people engage with one another during the week, which enabled me to formulate a first design hypothesis:
Primary Insight — People meet during the week primarily for shared activities, driven by common interests and proximity
Design Hypothesis — To build weekday traction, a feature must facilitate real-life activities based on shared interests, rather than attempting to replicate traditional dating or friend-finding apps
Analysing & Clustering the Findings
The interview transcripts were coded and clustered into themes according to the methodological principles of empirical social research, derived inductively from the categories previously defined for the user survey.
This process revealed several key conclusions across distinct focus areas:
Features — Prioritize discovering nearby events/happenings and connecting individuals with similar interests
Branding — Clearly position heystack as a social discovery app, differentiating it from dating apps
Barriers — Address top obstacles like lack of time and difficulty in finding like-minded people
Weekday Engagement — Develop features or incentives that specifically encourage weekday interactions
Interesting User Comment — "Group matches & meetup functionalities! I hate swiping on individuals on Bumble Friends because it has 'dating vibes.'”
IDEATION
Designing for Weekday Traction
To tackle weekday traction based on my research findings, I explored several approaches that align with heystack’s core value: connecting people in real-life settings through shared locations and interests.
Each concept aimed to encourage weekday engagement without compromising the app’s unique positioning.
Weekday Events or Hangouts — Location-based weekday events or meetups exclusive to heystack users, encouraging spontaneous in-person connections
Daily Challenges — Check-in-based challenges or tasks that reward users for engaging with venues on weekdays
Localized Content — Real-time, location-specific updates on trending venues or weekday-only social events
Collaborations — Partnerships with local businesses to offer exclusive weekday deals or experiences, incentivizing weekday app use
When Bumble Stole My Design
A few months after my work on this project, in winter 2023, Bumble rolled out a new feature called Plans — a concept strikingly similar to the design I had developed.
Rather than seeing this as mere coincidence, it reinforced a fundamental truth about great product design:
When you follow a strong research-driven process, you will likely arrive at similarly validated solutions.
This moment served as a testament to the scientific nature of product design — good research leads to good, evidence-based decisions. Seeing a major player implement a concept so close to mine only confirmed that I had been on the right track.
USER PERSONA
Meeting Outgoing Oliver
Personas have long been a valuable framework in UX design and marketing, helping teams build empathy and make clearer decisions by grounding designs in real user needs.
For me, personas have been a foundational tool for years — not only as a designer, but also during my time in Product Management and even earlier during my bachelor’s degree with a major in Marketing. Whether in product strategy, research, or design, I’ve consistently used personas to structure user insights, refine targeting, and guide decisions.
Over time, I’ve developed my own set of categories and characteristics that I find particularly effective for building personas, including:
Sinus Milieus to segment users based on socio-cultural lifestyles and values
Psychological Archetypes to understand deep-rooted behavior patterns and intrinsic motivations
Big Five Personality Traits to assess openness, conscientiousness, extraversion, agreeableness, and neuroticism, which influence how users interact with products and communities
During a workshop with one of the co-founders, we developed a primary persona named Outgoing Oliver, along with additional supporting personas.
I love going out, talking to people, and making new friends.
At 19 years old and living in Berlin, Oliver represents heystack’s core target audience. The detailed persona description is available on this Notion.
SECONDARY RESEARCH
Mapping Social Discovery Apps
Before moving into the design phase and prototyping, I conducted secondary desk research to better understand the current digital landscape for social discovery apps.
The goal was to analyze how competing platforms drive engagement on weekdays and extract best practices for increasing off-peak user activity.
Key focus areas included:
Return strategies — How platforms encourage users to come back during the week
Engagement mechanics — The role of time-based or recurring features in sustaining user activity
Beyond dating — How social discovery platforms differentiate themselves from dating apps
Within these areas, several patterns became evident that proved particularly relevant for heystack:
Time-based features drive engagement — Bumble introduced Speed Dating, a weekly event at a fixed time, which successfully created a scheduled in-app habit for users
Gamified experiences foster social interactions — Tinder’s Swipe Night turned engagement into a narrative-driven, shared activity, moving away from traditional swiping
Differentiation from dating apps is key — Both platforms incorporated community-based interactions, shifting from 1:1 matchmaking toward a more social networking experience
Creating urgency encourages participation — By offering limited-time interactions, both Tinder and Bumble gave users a reason to open the app on specific days, driving retention beyond casual browsing
Bumble Speed Dating
Bumble introduced a weekly Speed Dating Game, where users join the app at a designated time to engage in three-minute blind chats before seeing each other’s profiles. If the interaction clicks, they can choose connect and continue the conversation.
Scheduled —The feature runs every Thursday from 7–8pm, encouraging users to open the app at a set time, fostering real-time engagement on a weekday
Differentiated — By removing profile pictures initially, Bumble shifts the focus to conversation over appearance, differentiating it from traditional swiping
Tinder Swipe Night & Explore
Tinder launched interactive, event-driven features to enhance user engagement beyond passive swiping.
Swipe Night — A gamified, interactive story where users make choices to navigate a narrative, creating an engaging shared experience that fosters new connections
Tinder Explore — A redesigned app section focusing on social interactions and events, shifting Tinder away from its roots as a pure swipe-based dating app toward a more community-driven social platform
LITERATURE REVIEW
Building a Sticky Product
As part of my secondary research, I reviewed Hooked by Nir Eyal, one of the most influential works on habit-forming products.
The book provides a structured approach to understanding how products become so seamlessly integrated into daily life that we engage with them almost automatically, with little conscious thought.
Habit-forming products generate high user retention, strong engagement, and are difficult to compete with. According to Eyal, such products rely on users continuously going through the four stages of the Hook Model:
Trigger — An external event that initially introduces the product, such as a TV commercial or a social media ad
Action — The behavior required to use the product, such as signing up for an online community
Reward — The fulfillment of the initial motivation, such as being entertained when experiencing boredom
Investment — The personal value a user contributes to the product, such as time, money, or personal data
Once users transition from external triggers to internal triggers, they become hooked. A product successfully builds habits when users develop a mental association between the product and solving a personal need.
Applying the Hook Model
Social discovery apps like heystack are particularly tied to social motivations and emotional triggers. Eyal’s research suggests that most habitual product usage stems from two fundamental drivers:
When users associate a product with solving one of these core emotional needs, an internal trigger forms, making them more likely to habitually engage with the product.
The most powerful internal triggers are often tied to negative emotions — for instance, social networks and smartphones frequently trigger usage through boredom or fear of social disconnection.
According to behavioral models, a person only takes action if three conditions are met:
Ultimately, human motivation evolves around seeking pleasure, avoiding pain, gaining social acceptance, and avoiding rejection.
Products that align with these psychological drivers are far more likely to build long-term user habits — a key insight when designing for weekday traction in heystack.