I built a large-scale dog fitness app for animal physiotherapist Susanna Vartiainen from Siilinjärvi

Next.jsFull-stackSaaSStripeAWS S3MongoDB

siriusdog.filive

Overview

Sirius Dog Fitness is a professional-grade web application commissioned by animal physiotherapist Susanna Vartiainen to transform everyday dog walks into structured, effective musculoskeletal fitness sessions. The app delivers expert-guided 'gymnastic' exercises via text, images, and video — improving posture, muscle strength, range of motion, balance, and coordination. Before me, multiple developers had tried and either quoted too high a price or gave up halfway through the project. Then I stepped in.

The challenge

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The technical scope was significant: the app required a monthly subscription-based licensing system, cloud media hosting for videos and images, email automation, a gamification system with paw points, leaderboards and achievement badges, a 15-question mobility assessment test, informational 'Rest Stop' sections, and complex user management for two distinct target audiences.

The build

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I built the entire app as a Next.js full-stack solution with the following integrations: AWS S3 for video and media hosting, Stripe for monthly payments and license tiers, Resend for the email system, and MongoDB as the database. Features built: guided fitness paths with text/images/video, the Dog Days activity calendar, paw point scoring, leaderboards, achievement badges, and the mobility assessment test.

The result

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The client received exactly the app she had dreamed of. Result was, in her own words, better than she could have hoped for. The app is now live in production, actively serving both companion dog owners and sport & hobby dog enthusiasts.

Technologies

Next.jsFull-stackSaaSStripeAWS S3MongoDB