Senior Fullstack Engineer

Randstad (Schweiz) AG; London; On-site; GBP 60,000 - 80,000; Full time

Job summary

A leading recruitment and staffing agency in London is seeking a Senior Fullstack Engineer to take ownership of feature development from idea to product. The ideal candidate will have strong expertise in JavaScript, Node.js, and React, and thrive in a collaborative environment. This role offers competitive compensation and a culture that values technical excellence.

Benefits

Work on technically ambitious challenges

Direct ownership and impact

A culture that values technical excellence

Competitive compensation with health insurance

Opportunity to shape the product

Qualifications

• Strong experience delivering fullstack applications in fast-moving product environments.
• Deep expertise in JavaScript/TypeScript, Node.js, React, AWS, PostgreSQL.
• Strong problem-solving ability and attention to code quality and architectural integrity.

Responsibilities

• Take end-to-end ownership of features including architecture, testing, shipping and iteration.
• Design, build and maintain scalable applications across the stack.
• Collaborate closely with product and design to align technical execution with user needs.

Skills

JavaScript/TypeScript

Node.js

React

AWS

PostgreSQL

Problem-solving

Clear communication

Job description

About Us

Zelt is on a mission to rebuild how organisations run. Our all-in-one platform helps modern companies manage their people across payroll, onboarding, time off, IT provisioning and more, in a seamless and automated way.

We are the only platform on G2 named a Global Momentum Leader across HR, Payroll and IT, and we are just getting started. Our product is technically ambitious, structurally different from anything else on the market, and already trusted by forward-thinking companies.

About the Role

As a Senior Fullstack Engineer you will have the opportunity to take features from idea through design to shipped product. You will work in a lean, product-focused team where your input helps shape both what we build and how we deliver it.

Key Responsibilities

• Take end-to-end ownership of features including architecture, testing, shipping and iteration
• Design, build and maintain scalable applications across the stack (Node.js, TypeScript, React, AWS, PostgreSQL)
• Collaborate closely with product and design to align technical execution with user needs
• Write clean, maintainable and well tested code and champion engineering best practices
• Improve developer workflows, tooling and processes to keep the team fast and productive
• Stay on top of new technologies and suggest pragmatic, high impact improvements.

About You

• Strong experience delivering fullstack applications in fast-moving product environments
• Deep expertise in JavaScript/TypeScript, Node.js, React, AWS, PostgreSQL
• Strong problem-solving ability and attention to code quality and architectural integrity
• Clear communicator who thrives in collaborative environments
• Sense of ownership and pride in your work, motivated by outcomes rather than tasks.

️ Perks & Benefits

• Work on technically ambitious challenges that will stretch your skills
• Direct ownership and impact, with your work visible and influential from day one
• A culture that values technical excellence and continuous learning
• Competitive compensation with benefits including health insurance, equity and even airline miles
• The chance to join early enough to shape the product, but with product-market fit and momentum already in place.