Senior Front-End Engineer: Build Scalable Web Apps & SDKs

Segmentify; Greater London; On-site; GBP 90,000 - 120,000; Full time

Job summary

Segmentify is seeking a highly experienced frontend engineer to transform requirements into scalable technical solutions. You will collaborate with product, design, and customer success to deliver reliable deployments used by hundreds of Segmentify customers daily.

The role covers developing across React, Vue, or Svelte, building npm packages, and shaping Front-End CI/CD pipelines. A strong TS background and B2+ years of experience in BFF patterns are valued.

Qualifications

• 7+ years of professional web development experience.
• Deep knowledge of Babel, Vite, and esbuild (plugins, loaders, build optimization).
• Strong experience with npm package development and publishing (monorepo/workspace experience is a plus).
• Proven experience with GitHub Actions for front-end CI/CD.
• Hands-on BFF development experience (Node.js, preferably NestJS/Express).
• Advanced TypeScript knowledge (generics, utility types, strict mode, configuration optimization).
• Experience developing SDKs or client libraries and releasing them to production.
• Experience working on customer integrations and handling revision requests.
• English level B2 or higher – must be comfortable with technical communication, documentation, and client interactions.

Responsibilities

• Develop scalable, maintainable web applications using React, Vue, or Svelte.
• Manage customer integrations, write integration documentation, and support setup phases.
• Analyze and deliver customer revision and feature requests in a timely manner.
• Configure and optimize build pipelines with Babel, Vite, and esbuild (HMR, tree-shaking, code-splitting).
• Develop and publish npm packages with semantic versioning, changelogs, and automated releases.
• Build Front-End CI/CD pipelines with GitHub Actions (lint/test/build/storybook/e2e).
• Design and implement Backend-for-Frontend (BFF) layers with API orchestration, caching, rate limiting, and security best practices.
• Write robust, type-safe code in TypeScript with well-structured domain models.
• Develop SDKs and reusable libraries used by external developers/customers.
• Ensure code quality through unit/integration testing, code reviews, and performance/security improvements.

Skills

TypeScript

React

Vue

Svelte

Babel

Vite

esbuild

npm package development

GitHub Actions

Monorepo / workspace

NestJS / Express (BFF)

Education

BSc or MSc in Computer Science / Software Engineering

Tools

NestJS

Express

pnpm/npm

Storybook

Playwright

Vitest/Jest

Job description

Segmentify is seeking a highly experienced frontend engineer to transform requirements into scalable technical solutions. You will collaborate with product, design, and customer success to deliver reliable deployments used by hundreds of Segmentify customers daily.

The role covers developing across React, Vue, or Svelte, building npm packages, and shaping Front-End CI/CD pipelines. A strong TS background and B2+ years of experience in BFF patterns are valued.