# Similarity: A Collaborative Filtering Approach to Modern Dating Platforms Revisiting the pre-Tinder era through a custom-built, interest-based matching engine. - **Source:** [Hacker News: Show HN](https://news.ycombinator.com) - **Published:** 2026-10-31 - **Topic:** [Entrepreneurship](https://brifing.si/c/entrepreneurship) - **Original article:** - **On Brifing:** https://brifing.si/s/bbbb6409-7312-4b8c-9558-76ba2f38c337 ## Project Origin and Philosophy Similarity functions as an experimental dating platform inspired by the 1990s moviecritic.com site. Unlike modern swipe-based applications, the project focuses on collaborative filtering to match users based on shared tastes. The developer intends for the platform to remain engaging for non-single users, prioritizing interest-based connections over traditional dating mechanics. ## Technical Stack Architecture The application utilizes a robust stack featuring Java, Guice, and Gwizard for backend operations. Frontend interactions are managed via React and Jotai, while data persistence is handled by Neon Postgres. The infrastructure is deployed on AWS Elastic Beanstalk, incorporating Cloudflare services to ensure the entire system remains scalable, cost-effective, and automated. ## Custom Matching Engine Logic The core innovation lies in a custom in-memory matching engine designed to process user preferences efficiently. The developer utilized LLMs to assist with load testing and performance optimization of this structure. This technical milestone allowed for a responsive matching experience that avoids the common latency issues found in traditional database-heavy query systems. ## Leveraging AI for Development The project integrates AI tools, specifically relying on the Codex model under a twenty-dollar monthly subscription plan. While the developer notes that token usage remains relatively low, the AI played a crucial role in refining the engine's performance. This demonstrates a practical, low-cost application of generative models in personal software development. ## Addressing Market Challenges The developer acknowledges the classic chicken-and-egg problem inherent in launching new social or dating platforms. Currently, the project maintains low expectations for immediate user growth, focusing instead on technical stability and feature refinement. Strategic ideas to bootstrap initial user acquisition are in the planning phase while the project remains a side-hustle. ## Operational Sustainability Strategy Similarity is built to be a hands-off, low-maintenance project that complements the developer's full-time day job. By utilizing PaaS solutions, the infrastructure scales automatically without requiring constant manual intervention or high operational overhead. This approach ensures the platform remains financially sustainable even with a minimal user base during the early stages. ## Design Philosophy vs Tinderization The platform explicitly rejects the swipe-based interface that dominates the current dating market. By aiming to capture the appeal of 2000s-era OkCupid, the project prioritizes depth and shared interests over rapid visual judgment. This design choice targets users who feel alienated by the gamified, high-velocity nature of contemporary mobile dating applications. ## Future Development and Feedback The project is currently in an open-testing phase, allowing users to explore functionality without mandatory sign-ins. The developer is actively seeking community feedback to refine the matching algorithms and user experience. This iterative approach highlights the value of building niche, passion-driven software projects that prioritize technical experimentation over immediate commercial scaling. ## Sources covering this story - https://similarity.com — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._