Yannick Mermet

About Me

I'm a Senior Frontend Engineer with 10+ years in software engineering, including 4 years building institutional crypto custody at io.finnet. Frontend-first with fullstack ownership and an AI-native workflow in Claude Code.

Since August 2022 I've been responsible for all frontend delivery across web and mobile at io.finnet: I led and architected the full platform redesign, built the 90+ component library as its sole maintainer, and shipped multi-chain tokenization and Solana signing end to end in React, Next.js, and TypeScript. Before that I built real-time energy analytics at Vortexa and high-traffic ticketing platforms at Live Nation.

Outside of work I build side projects at the intersection of AI, Web3, and automation. Bilingual English/French, certified Scrum Master, MSc Computer Science from the University of Warwick. Advocate for test-driven development and atomic design systems.

Skills

Languages
TypeScriptJavaScriptHTMLCSSSCSSSolidity
Frontend
ReactNext.js (App Router)React NativeExpoTailwind CSSshadcn/ui
State Management
TanStack Query (React Query)React Hook FormZod
Automated Testing
VitestReact Testing LibraryPlaywright (E2E)TDD
Web3
EthereumSolanaBitcoinTronWalletConnectsmart contractsMPC custodytokenization
APIs and Cloud
GraphQLRESTOpenAPINode.jsAWS (AppSync, Lambda, DynamoDB, S3)Serverless FrameworkPostgreSQLElasticsearchVercelDockerTerraform
Tooling
FigmaGitHub ActionsCI/CDTurbopackSentryClerkGitAgile
AI Development
Claude Code (agentic workflows)Claude Design (design system)

Experience

Aug 2022 – Present · Grand Cayman

io.finnet

Senior Full Stack Engineer (Frontend)

Startup providing institutional self-custody of blockchain assets, built on Multi-Party Computation (MPC) threshold signing.

  • Led and architected the complete redesign of the custody platform in Next.js, React, and TypeScript, owning all frontend delivery and making every screen responsive across desktop, tablet, and mobile.
  • Built the 90+ component library used by io.finnet's core product, structured by atomic design on shadcn/ui and Tailwind CSS with accessibility and subtle animation built in, and remain its sole maintainer.
  • Built the tokenization product end to end, including a multi-chain deploy wizard for io.finnet's own EVM chain and Liquid Bitcoin.
  • Delivered Solana support, including a two-phase durable nonce signing flow that reconciles Solana's transaction expiry of 60 to 90 seconds with a 24-hour MPC signing window.
  • Developed the cross-platform mobile signing app in React Native and Expo, letting users authorize MPC transactions with biometric authentication on iOS and Android.
  • Reduced CI/CD pipeline runtime by 60% (from 25 to 10 minutes) with matrix sharding and parallel workers, migrated production builds to Turbopack, and stabilized Playwright end-to-end (E2E) test runs.
  • Integrated agentic workflows in Claude Code across the team for test generation and code review, increasing pull request throughput, and mentored a backend engineer on frontend patterns.
TypeScriptReactNext.jsReact NativeExpoTailwind CSSshadcn/uiSolanaMPC custodyTokenization
Jan 2021 – Aug 2022 · London

Vortexa

Full Stack Engineer

Real-time energy analytics platform tracking $3T+ in global waterborne oil and gas trades.

  • Led the frontend architecture and delivery of a real-time data correction tool, working with internal analysts to improve data accuracy across the platform.
  • Built React and TypeScript dashboards visualizing real-time shipping and trade data for 5,000+ daily users.
  • Redesigned core components of the analytics platform, improving API performance and stabilizing Elasticsearch under high-volume queries against a continuously updated dataset of 1M+ records.
  • Rebuilt the internal account management system used daily by the operations team.
TypeScriptReactElasticsearchREST
Apr 2018 – Nov 2020 · London

Live Nation Entertainment

Software Engineer

World's largest live entertainment company, operating ticketing, venues, and artist management across 40+ countries.

  • Shipped features in C# and .NET Core across 30+ international ticketing sites serving 40+ countries.
  • Improved search speed and relevance through Elasticsearch query tuning, bringing response times under 250 ms, and managed deployment and scaling with Docker, AWS, and Terraform for high-traffic services.
C#.NET CoreDockerAWSTerraformElasticsearch
Sep 2015 – Mar 2018 · London

RibbonFish

Application Support Developer

Technology consultancy specializing in CRM and Salesforce solutions for publishing and media companies.

  • Developed and supported client applications in VB.NET, C#, and ASP.NET, plus Salesforce integrations, for publishing and media companies.
VB.NETC#ASP.NETSalesforce

Education

Master of Science (MSc) in Computer Science

University of WarwickCoventry, United Kingdom · 2015