# Tony Tang > Head of Engineering · Paris, France. I lead teams that build and scale web products, and I'm taking my team AI-first. Open to freelance (evenings & weekends). - Email: tony@tonytang.dev - tonytang.dev: https://tonytang.dev/ - LinkedIn: https://www.linkedin.com/in/tony-tang-671248b1/ - GitHub: https://github.com/tonytangdev - YouTube: https://www.youtube.com/channel/UCaJEuCzLyx6nEDOg0_kvldw - Learn Effect (course): https://learn-effect-ts.tonytang.dev - CV: https://cv.tonytang.dev/ (PDF: https://cv.tonytang.dev/tony-tang-cv-en.pdf) ## Highlights - Lead a team of 5 developers as Head of Engineering at Fonts Ninja. - 5 years at Planity, France's leading beauty booking platform (40,000+ salons, around 10M appointments a month), the last 3 leading a team of 4 to 6 developers. - Hired 2 senior developers, and mentored around 20 developers. Most of the developers I led at Planity were promoted. - Led a zero-downtime migration that made Planity's salon dashboard much faster and fixed long-standing wrong totals. - Taking my team AI-first: production errors are now triaged by AI, and developers and our Product Owner use AI to explore the codebase. ## About I'm Tony, Head of Engineering at Fonts Ninja in Paris, with around 10 years of experience building web products. I lead a team of 5 developers: I choose our technologies, set our standards and make the final technical calls, and I have a direct say in the product direction. Before that, I spent 5 years at Planity, France's leading beauty booking platform, first as a developer and then leading a team of 4 to 6 developers. Today I focus on systems that handle large volumes of data, and on using AI to change how my team works. I have also mentored around 20 developers on Codementor. ## What I can help with - **Build or rescue a web product:** Web apps, APIs and back-office tools, from the first version to production, built so your team can maintain them. - **Backend and data pipelines:** Systems that collect and process large volumes of data reliably: web scrapers, queues and background jobs. - **Make your team AI-first:** Set up AI tools and workflows so your developers ship faster without lowering quality. - **Part-time tech leadership:** Technical decisions, code review, hiring and mentoring for teams without a senior lead. ## Experience ### Head of Engineering, Fonts Ninja Feb 2026 – Present Makes a browser extension that identifies the fonts on any website (900k users on Chrome), and Font Radar, a service that finds websites using fonts without a license so that type foundries get paid. - Lead a team of 5 developers: I choose the technologies, set the standards and make the final call when the team disagrees on a solution. - Have a direct say in the product direction, in a smaller company with broader responsibilities than my previous role. - Hired 2 senior developers, one of whom now works with us remotely from Korea. - Taking the team AI-first: AI now triages our production errors, and both the developers and our Product Owner use AI to explore the codebase. - Leading the step-by-step modernisation of how we process data, planned to keep downtime to a minimum. How it was done: - Set the team's coding standards and enforce hexagonal architecture through code review; I step into every project to validate solutions when developers have doubts. - Leading the migration from legacy database queues to BullMQ and Redpanda: easiest or most valuable parts first, every data flow mapped and each step planned. - Automated AWS and Sentry error triage with AI, and set up AI codebase analysis. Tech: NestJS, TypeScript, Next.js, MySQL, BullMQ, Redpanda, AWS SQS, AWS ECS, AWS S3, AWS Lambda, Cloudflare, Claude Code ### Backend Developer, Fonts Ninja Apr 2025 – Feb 2026 - Joined as a backend developer on the systems behind both products. - Worked on the Font Radar robots, which scan 30M new websites a day to find those most likely to be using fonts without a license. - Built and maintained many automations and data-collection tools. How it was done: - Started migrating legacy database queues to BullMQ and Redpanda, so that many workers can run in parallel on an ever-growing database and their progress is easy to track. - Built and maintained web scrapers. Tech: NestJS, TypeScript, MySQL, BullMQ, Redpanda, AWS SQS, AWS ECS, AWS S3, AWS Lambda, Web Scraping ### Lead Developer, Planity Feb 2022 – Feb 2025 France's leading beauty booking platform: 40,000+ salons and around 10M appointments a month, also in Belgium and Germany. - Led a team that grew from 4 to 6 developers over 3 years, one of the teams created as Planity scaled its engineering. - Mentored the developers I worked with: most of them were promoted, and some became Lead Developers themselves. - Estimated project timelines, planned delivery and reviewed the team's work for readability, correctness and security. - Led the zero-downtime move of the salon statistics dashboard to a new system: it became much faster, cheaper to run, and long-standing wrong totals were fixed. How it was done: - Migrated the dashboard from Firebase to Elasticsearch, replacing precomputed caches with query-time aggregations. - Validated the approach with a proof of concept, then designed the migration: dual-writes, an idempotent and resumable backfill of millions of records with AWS Step Functions and Lambda, per-salon validation of every total, and a feature-flag cutover rehearsed in preprod. - Spent most of my time reviewing pull requests rather than writing code. Tech: Elasticsearch, Firebase, AWS Step Functions, AWS Lambda ### Fullstack Web Developer, Planity Feb 2020 – Feb 2022 - Built features for the public booking app, on web and mobile, and for Planity Pro, the software salons use to run their business. - Built a point-of-sale system for salons in Germany, and integrated online payments and Shopify. - Designed large features, and planned releases so that customers still on older versions of the app kept working. How it was done: - Worked on the AWS backend (Lambda, S3, API Gateway, OpenSearch) and on real-time updates with Firebase and Firestore. - Integrated Stripe and Shopify, and worked on database sharding. Tech: React, React Native, Redux, XState, Firebase, Firestore, AWS Lambda, AWS S3, AWS API Gateway, AWS OpenSearch, Algolia, Stripe, Shopify ### Software Engineer, LCL (work-study) Nov 2017 – Oct 2019 French retail bank. - Added features to an internal banking application that many employees depended on every day. - Worked with other teams to integrate new features into the existing system. - Wrote automated tests to keep this business-critical application reliable. How it was done: - The application was built on an older version of Java. Tech: Java ### Web Developer, FWA (work-study) Aug 2016 – Oct 2017 - Maintained a complex business web application. - Made database queries faster and took part in database migrations. How it was done: - The application was built with C# and ASP.NET on the company's in-house template system. Tech: C#, ASP.NET, SQL, MySQL ## Education - Expert in Computer Science and Information Systems (Master's level), Supinfo (2014 – 2019) - AWS Certified Solutions Architect – Associate (SAA-C01, expired), Amazon Web Services (Oct 2018 – Nov 2020) ## Leadership skills Engineering Management, Team Leadership, Hiring, Mentoring, Code Review, Delivery Planning, Technical Decision-Making, AI Adoption ## Technical details ### Technical skills - Languages & frameworks: TypeScript, Node.js, NestJS, Next.js, React, React Native, Redux, XState - Architecture: System Design, Hexagonal Architecture, Web Scraping - Data & messaging: SQL, MySQL, NoSQL, Elasticsearch, BullMQ, Redpanda (Kafka), Firebase, Firestore, Algolia - Cloud: AWS ECS, AWS SQS, AWS Lambda, AWS S3, AWS Step Functions, AWS DynamoDB, AWS API Gateway, AWS OpenSearch, Cloudflare - AI: Claude Code, AI automation (LLMs) - Payments & commerce: Stripe, Shopify ### Projects #### Fonts Ninja Extension Identifies any font on any website in one click, using Font DNA, an in-house algorithm that analyses the actual font file rather than the CSS. 900k users on Chrome (rated 4.4/5), also available on Firefox and Safari. Tech: TypeScript, Browser extension Link: https://chromewebstore.google.com/detail/fonts-ninja/eljapbgkmlngdpckoiiibecpemleclhh #### Font Radar License enforcement for type foundries. A set of robots and jobs scans over 30M new websites a day (from CTDomains), builds a database of 1B+ websites and 10M+ apps, and finds those using fonts without the appropriate license, so that foundries get paid for their work. Tech: NestJS, TypeScript, MySQL, BullMQ, Redpanda, AWS SQS, AWS ECS, AWS Lambda, Web Scraping Link: https://www.fontradar.com #### Planity France's leading beauty booking platform, with 15M users a month, also available in Belgium and Germany. I worked on both the web and mobile apps. Tech: React, React Native, XState, Firebase, Firestore, AWS Lambda, AWS API Gateway, AWS DynamoDB, AWS S3, Algolia, Stripe Link: https://planity.com #### Planity Pro Management software for salon professionals on web, tablet and phone: real-time calendar and appointment management, plus a point-of-sale system used in France, Belgium and Germany. Tech: React, Redux, Redux Saga, Firebase, Firestore, AWS Lambda, AWS Step Functions, AWS DynamoDB, AWS OpenSearch, Algolia, Stripe Link: https://pro.planity.com #### Mentoring on Codementor Mentored around 20 developers on Codementor, helping them with their React, Next.js, Node.js, TypeScript and MongoDB projects. Tech: React, Next.js, Node.js, TypeScript, JavaScript, MongoDB, HTML, CSS Link: https://www.codementor.io/@tonytangdev Updated 2026-11-01.