Yanis – Next.js, Typescript, React

A pastry shop needed to sell cakes and desserts online and coordinate production and delivery without handling orders by phone and email. The e-commerce platform covers the storefront, checkout and payments, order management, fulfillment, and delivery tracking, with multilingual support for local and international customers.

• Built the entire e-commerce platform as the sole developer, covering the storefront and admin workflows for products, orders, checkout, payments, fulfillment, and delivery tracking.
• Designed a reliable notification system that used a Firestore collection as a queue with cron-based retries, so order emails and SMS still reached customers when providers failed.
• Integrated Firebase/Firestore, Cloud Functions, email services, and the production-and-delivery workflow tool.
• Optimized images and rendering with ISR, responsive images, and Sharp to improve Core Web Vitals.
• Added multilingual support and deployed the application on Vercel and Google Cloud.

Websites and web applications built remotely for small and mid-sized businesses by an independent contractor, ranging from marketing websites to custom web apps with admin panels and databases.

• Built websites and web applications for clients remotely, from gathering requirements to deployment and maintenance.
• Developed early client projects in PHP and JavaScript and moved newer work to Next.js, React, MongoDB, and Cloud Firestore.
• Set up and maintained Nginx-based hosting for client websites.

Gyms and fitness studios often run memberships, class bookings, and check-ins on spreadsheets and disconnected tools. The multi-tenant SaaS gives each studio a staff dashboard and its own branded member app (PWA) for memberships, recurring class schedules, bookings and waitlists, QR check-ins, and personal training.

• Built the gym management SaaS end-to-end, including client and membership management, recurring class schedules, bookings and waitlists, QR check-ins, and personal training workflows.
• Implemented tenant isolation and role-based access with Supabase Auth, PostgreSQL, and row-level security.
• Built branded member PWAs in Next.js so each studio could offer its own app to members.

Operational teams such as bakeries and delivery businesses lose track of work when orders, production tasks, and deliveries live in separate tools. The multi-tenant workflow SaaS turns incoming e-commerce orders into production tasks and tracks them on boards, tables, and calendars, with live delivery tracking and a mobile app for couriers.

• Built the workflow SaaS with board, table, and calendar views, workspace onboarding, real-time updates, and authenticated integration APIs that sync e-commerce orders into production tasks.
• Developed delivery tracking with live GPS, delivery photos, and offline queues, plus a Capacitor mobile app for couriers.
• Built the data layer and authentication on Supabase and PostgreSQL.

A web platform that lets users download videos and images from Instagram, YouTube, TikTok, X, and Pinterest in one place, with free and premium access tiers.

• Built the download APIs, account authentication, premium access checks, admin dashboards, and download activity logging.
• Implemented queued YouTube downloads with background workers and S3-compatible storage, so long downloads ran without blocking the app.
• Built the front end and content pages with Next.js, React, and Contentful.

Game publishers struggle to find content creators to promote their games, and creators struggle to find paid partnerships. The platform connects publishers, creators, and players in one place, supporting game discovery, creator partnerships, and promotional campaigns for marketing and selling video games.

• Developed the interfaces for the Publisher, Creator, and Player portals, covering game discovery, creator partnerships, and promotional campaigns.
• Built the platform’s front end in Next.js and React as part of a small product team.

Energy consumption data reported by suppliers is hard for end users and regulators to verify. Built under an EU-funded research program, the platform lets energy suppliers report their end users’ energy consumption and publishes the metrics and KPIs on a blockchain, making the data tamper-evident and transparent.

• Integrated blockchain publishing into the partner’s energy platform, writing consumption metrics and KPIs on-chain for integrity and transparency.
• Built the integration with Node.js and React together with the partner’s engineering team.

A website that helps users decide which Android apps to install by publishing reviews with pros and cons for apps listed on Google Play. The review content is generated automatically with AI from app store data.

• Built the website end-to-end: Google Play app data fetching, OpenAI-generated reviews with pros and cons, and a Strapi CMS on PostgreSQL.
• Built the front end in Next.js.

A private, multi-tenant real estate platform used by several real estate businesses, each working in its own isolated space.

• Developed the platform’s front end with React and Next.js, integrating the APIs built by the back-end developer.

Game studios need new ways to monetize and retain players without building their own reward systems. The platform lets game developers create battle passes with off-chain and on-chain rewards and integrate them into their games through a Unity SDK.

• Built the platform’s front end in Next.js and Tailwind CSS, including the dashboards game developers use to create and manage battle passes.
• Integrated Stripe payments and Web3 wallet support with Wagmi and Viem for on-chain rewards.
• Turned Figma designs into production UI.

An NFT collection’s holder community needed ongoing reasons to stay engaged after the mint. The platform gives holders a suite of web apps and games: a social network with feeds, direct messages, and NFT interactions, a bingo game where players mint their boards, and a pixel-art app whose winning artwork becomes a new NFT collection.

• Designed the architecture and infrastructure for the community’s suite of web apps and games.
• Built the community social app with feeds, direct messages, and NFT interactions, including NFT renaming and ID-card image updates reflected on OpenSea.
• Built a bingo app where users minted bingo boards and organized games.
• Built a pixel-art app with drawing and voting, where the winning artwork was minted as an NFT collection.
• Fixed a production bottleneck where a surge of mint events made Cloud Functions time out during CPU-heavy image generation, by moving processing to a Firestore task queue with retries, user-visible status, and scheduled asynchronous processing.

Esports organizers needed a way to run tournaments with crypto prize pools that are paid out to players transparently. The platform hosts esports tournaments with token and NFT prize pools on Ethereum, Polygon, BNB Chain, Ronin, and Solana, including tournaments with prize pools of up to $1M.

• Integrated Ronin injected and mobile wallets together with the Web3 back-end lead under a tight deadline for a $1M tournament for a major blockchain game.
• Integrated smart contract functionality into the UI and added multi-chain blockchain and wallet support.
• Added support for NFTs as tournament prize pools.
• Interviewed Web3 candidates, mentored two junior developers, and coordinated feature releases with the front-end, back-end, and Web3 leads.

Holders of an NFT collection needed tools to mint, trade, and share their NFTs. The suite of web apps covers the pre-mint and mint flow, an NFT matching and trading app with smart contract exchanges, NFT swap pools, and a meme generator for sharing NFTs on social media.

• Led the application architecture and a team of two front-end developers and one blockchain developer while building features full-stack.
• Built pre-mint and mint apps with Merkle-tree whitelists and NFT ownership checks.
• Built an NFT matching and trading app with smart contract exchanges and a Cloud Functions/Firestore notification back end.
• Built an NFT swap-pool app with optional swap fees, front end and back end.
• Built a meme app for NFT image selection, captioning, and sharing via the Twitter and Discord APIs, plus Node.js Discord/Twitter bots and blockchain listeners for sales, swaps, and matches.

An esports tournament platform where players compete in organized online tournaments, run and displayed through interactive tournament brackets.

• Built a new tournament bracket UI system in React for the platform’s esports tournaments.

Small and mid-sized companies need cyber insurance, and they also need to reduce the risk of attacks such as phishing in the first place. The platform sells cyber insurance policies and trains employees to recognize security threats. The company was later acquired.

• Built the platform’s entire front end with React and Redux on a Firestore database.
• Integrated the platform’s APIs together with two back-end developers.
• Deployed the web applications on Heroku with a Google Cloud back end.

A platform that helps users connect and engage directly with their Twitter followers.

• Built the platform’s back-end services in Node.js on Firestore.
• Covered the back-end services with automated tests in Jest.

During the COVID-19 lockdowns, elderly and high-risk people needed help with everyday tasks without leaving home. The volunteering platform connected them with local volunteers for shopping, dog walking, and other support, showing requests on a map.

• Built the volunteer matching platform’s front end in React and Redux, with Leaflet maps showing help requests near volunteers.
• Designed the UI in Figma.

A movie streaming platform with free and premium tiers, serving 8K registered users, 2K premium users, and about 50K monthly visits.

• Built the Strapi/MongoDB admin dashboard for managing movies, users, and premium access, plus the React front end.
• Configured a dedicated Ubuntu server with Nginx, PM2, and MongoDB and deployed the application on it.