Senior Frontend Engineer

sls.guru

Wilmington (DE)

On-site

USD 120,000 - 180,000

Full time

13 days ago

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Job summary

sls.guru is seeking a Senior Front-End Developer to join our engineering team. You will build modern, scalable web applications using React and TypeScript, collaborating with product managers, designers, backend engineers, and QA to deliver business-critical workflows.

You will work across feature development, frontend architecture, API integration, performance optimization, and platform improvements, joining a mature codebase with established engineering standards and modern tooling.

Qualifications

Experience with React-based front-end development for large-scale applications.
Strong proficiency in TypeScript and modern front-end patterns.
Experience with TanStack Router, TanStack Query, and TanStack Form.
Proficiency in Tailwind CSS and Vite for efficient UI builds.
Focus on accessibility (WCAG) and performance optimization.

Responsibilities

Build new product features using React, TypeScript, and TanStack tools.
Develop reusable UI components within a shared design system.
Integrate frontend with backend APIs and platform services.
Build and maintain complex forms and data-driven UIs.
Improve performance via code splitting and modern React practices.
Maintain frontend architecture and implement engineering standards.
Improve accessibility, testing, observability, and developer experience.
Contribute to tooling, CI/CD pipelines, and deployment processes.
Collaborate with product, design, backend, and QA teams to ship high-quality software.

Skills

React

TypeScript

TanStack Router

TanStack Query

TanStack Form

Tailwind CSS

Vite

Accessibility (WCAG)

OAuth / OIDC

CI/CD pipelines

Infrastructure as Code

Component-driven development

Frontend performance optimisation

Job description

About The Role

We are looking for a Senior Front-End Developer to join our engineering team and help build modern, scalable web applications that support business-critical workflows across the organisation. This is a hands‑on engineering role for someone who enjoys building high‑quality user experiences using React and TypeScript.

Senior Front-End Developer

Frontend Engineering

React

TypeScript
TanStack Router
TanStack Query
TanStack Form
Tailwind CSS
Vite

About The Role

You will work across feature development, frontend architecture, API integration, performance optimisation, and platform improvements while collaborating closely with product managers, designers, backend engineers, and QA.

You will be joining a mature codebase with established engineering standards, modern tooling, and well‑defined architectural patterns.

We value engineers who take ownership, make thoughtful technical decisions, and care about building software that is reliable, easy to maintain, and enjoyable for other engineers to work in.

What You'll Work On

Build new product features using React, TypeScript, and the TanStack ecosystem.
Develop reusable, accessible UI components using a shared design system.
Integrate frontend applications with backend APIs and platform services.
Build and maintain complex forms, workflows, and data‑driven user interfaces.
Improve application performance through code splitting, rendering optimisation, and modern React best practices.
Maintain and evolve frontend architecture while following established engineering conventions.
Improve accessibility, testing, observability, and overall developer experience.
Contribute to frontend tooling, CI/CD pipelines, and deployment processes where appropriate.
Collaborate with cross‑functional teams to deliver high‑quality software from design through production.

Required Experience

React

Strong experience building large‑scale applications using modern React.
Deep understanding of hooks, component composition, Context, Suspense, lazy loading, concurrent rendering, and rendering lifecycle.
Strong understanding of React performance optimisation, memoisation, and rendering behaviour.
Experience designing reusable component libraries and scalable frontend architectures.
Ability to reason about state ownership, derived state, effects, and component responsibilities.

TypeScript

Strong experience writing production applications in TypeScript.
Comfortable working with strict typing, discriminated unions, utility types, generics, and advanced type inference.
Experience using TypeScript to improve application design and developer experience.

TanStack Router

Experience building applications using nested routing, route loaders, search parameter validation, route guards, and code splitting.

TanStack Query

Strong understanding of server‑state management, caching, mutations, optimistic updates, invalidation strategies, and Suspense‑first data fetching.

TanStack Form

Experience building complex forms with validation, dynamic fields, and schema‑driven form management.

Zod

Experience building reusable validation schemas and leveraging type inference across APIs, routing, and forms.

STRONG TO HAVE

Tailwind CSS
Vite
Frontend performance optimisation
Accessibility (WCAG)
Modern authentication patterns (OAuth / OIDC)
Frontend observability tooling
Component‑driven development
CI/CD pipelines
Infrastructure as Code
Experience working on large enterprise applications

How You Think

You value maintainability over cleverness.
You understand when to introduce abstractions and when to keep solutions simple.
You write code that is easy for other engineers to understand and extend.
You think carefully about API design, component boundaries, and separation of concerns.
You understand the difference between local UI state, URL state, and server state, and choose the appropriate tool for each.
You leverage TypeScript as a design tool rather than simply a type checker.
You proactively identify opportunities to improve performance, accessibility, and developer experience.
You take ownership of the systems you build and consider long‑term maintainability alongside feature delivery.

What We Explore In The Interview