Yannick Mermet

About Me

I'm a senior engineer with 10+ years shipping production React and Next.js applications, including 4 years in fintech and Web3. I work across the full stack but I'm frontend-first: I care about interfaces that are fast, clear, and trustworthy.

For the past 2 years I've led frontend delivery on an institutional digital asset custody platform at io.finnet, owning the design system, real-time transaction interfaces, tokenisation, and a React Native signing app. Before that I built real-time energy analytics at Vortexa and high-traffic ticketing platforms at Live Nation, each with its own performance ceiling and domain to absorb.

My full-stack background spans TypeScript, GraphQL, and AWS serverless, with AI-assisted development (Claude Code) embedded in daily delivery. 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.

Technologies I work with

TypeScript
React
Next.js
Node.js
Tailwind CSS
SCSS
GraphQL
Apollo Client
TanStack Query
Zod
Vitest
Testing Library
Expo
Solidity
Ethereum
Solana
AWS
Docker
Terraform
Vercel
Cloudflare
Sentry
PostgreSQL
DynamoDB
Elasticsearch
Git
GitHub Actions

Experience

Aug 2022 – Present · Cayman Islands (Remote)

io.finnet

Senior Full Stack Engineer

Institutional digital asset custody platform using MPC cryptography for secure self-custody and settlement. Frontend-focused since 2024, owning the web dashboard, design system, and mobile signing app.

  • Led frontend delivery of the tokenisation product: token issuance and administration across EVM, Solana, Tron, and Liquid, with every on-chain action gated by multi-signature approval policies.
  • Owned production observability, upgrading Sentry v7 to v10 and eliminating a 32,000-event noise source to restore usable crash reporting.
  • Defined the codebase data-fetching architecture and migrated every server-side fetch onto one typed client, cutting error-handling code by 35%.
  • Built and maintained a reusable component library adopted across 3 products by a 10-engineer team, cutting UI development time and design inconsistencies.
  • Developed the mobile signing application in React Native and Expo, letting users authorise MPC transactions with biometrics on iOS and Android.
  • Shipped real-time transaction interfaces on AWS AppSync and GraphQL subscriptions, tracking live state across institutional accounts.
  • Cut CI/CD pipeline runtime by 60% (25 → 10 min) via matrix sharding and parallel workers, unblocking daily deploys for the frontend team.
  • Introduced AI-assisted development (Claude Code) across the team, automating E2E test generation and speeding up code review.
TypeScriptReactNext.jsReact NativeGraphQLAWSTokenisationMPC Cryptography
Jan 2021 – Aug 2022 · London, UK (Remote)

Vortexa

Full Stack Engineer

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

  • Built a suite of React and TypeScript dashboards styled with TypeStyle, visualising real-time shipping and trade data and surfacing complex market movements to traders and analysts.
  • Led frontend architecture and feature delivery for a real-time data correction tool, partnering with internal analysts to ship workflows that improved data accuracy across the platform.
  • Rebuilt the internal account management system, streamlining platform access for the operations team and enabling advanced support workflows used daily across the company.
  • Redesigned core components of the analytical platform, reducing API response times and stabilising Elasticsearch domains under high-volume query load from a continuously updated dataset of 1M+ records.
TypeScriptReactTypeStyleElasticsearchREST APIs
Apr 2018 – Nov 2020 · London, UK

Live Nation

Software Engineer

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

  • Developed and shipped features across 30+ Live Nation international sites using C# and .NET Core, contributing to continuous delivery for ticketing platforms operating across 40+ countries.
  • Managed deployment and scaling using Docker, AWS, and Terraform, supporting stable production environments across high-traffic ticketing services.
  • Improved search functionality by refining Elasticsearch queries and extending the Search API middleware in C# and .NET Core, enabling faster and more relevant results across Live Nation properties.
C#.NET CoreDockerAWSTerraformElasticsearch
Sep 2015 – Mar 2018 · London, UK

RibbonFish

Application Support Developer

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

  • Developed and supported client applications using VB.NET, C#, ASP.NET, and Salesforce integrations.
VB.NETC#ASP.NETSalesforce

Education

Master of Science (MSc) in Computer Science

University of WarwickCoventry, United Kingdom · 2015