Full Stack Engineer

LA International; United States; Hybrid; USD 98,000 - 111,000; Part time

Job summary

LA International is seeking a Full Stack Engineer for a 3-month contract with possible extensions, based in London with hybrid pattern (on-site up to 3 days per week).

We require strong backend in Java/Python with Spring Boot, strong frontend in HTML/CSS/JS and React, REST APIs, and database expertise.

This opportunity offers exposure to leading organisations and cutting-edge tech, with an umbrella rate of £400-£450 per day.

Qualifications

• Experience delivering full-stack web and mobile backends.
• Proficient in Java or Python with Spring/Spring Boot.
• Strong React front-end with RESTful API integration.

Responsibilities

• Developing and maintaining scalable front-end and back-end applications for web and mobile platforms.
• Collaborating with designers, product managers, and other engineers to build user-friendly, high-performance software.
• Writing clean, efficient, and maintainable code while adhering to best practices in software development.
• Implementing APIs and ensuring seamless integration between front-end and back-end systems.
• Testing, troubleshooting, debugging, and optimising existing/new systems for performance and scalability.
• Participating in code reviews, providing constructive feedback, and maintaining quality standards.

Skills

Java

Python

React

HTML5/CSS3/JS

Spring Boot

REST APIs

MVC patterns

JWT/OAuth2

SQL

Tools

Docker

Kubernetes

JUnit

Mockito

Redux

React Testing Library

Jest

Cypress/Playwright

Kafka

RabbitMQ

Job description

Full Stack Engineer 3 Month contract initially + Extensions Based: Hybrid - Max 3 days p/w onsite in London Rate: £400 - £450 p/d - (via Umbrella company)

We have a great opportunity with a world leading organisation where you will be provided with all of the support and development to succeed. A progressive organisation where you can really make a difference. We have a great opportunity for a Full Stack Engineer to join the team.

Key Responsibilities

• Developing and maintaining scalable front-end and back-end applications for web and mobile platforms.
• Collaborating with designers, product managers, and other engineers to build user-friendly, high-performance software.
• Writing clean, efficient, and maintainable code while adhering to best practices in software development.
• Implementing APIs and ensuring seamless integration between front-end and back-end systems.
• Testing, troubleshooting, debugging, and optimising existing/new systems for performance and scalability.
• Participating in code reviews, providing constructive feedback, and maintaining quality standards.

Key Skills/knowledge/experience:

• Backend: Strong Java/Python skills with Spring and Spring Boot
• Frontend fundamentals: Strong HTML5, CSS3, and JavaScript (ES6+)
• Modern frontend framework: Hands-on experience with React Js
• Component architecture and state: Component-based design and state management (React Hooks, Redux, Context, or NgRx)
• Responsive UI: Building responsive, cross-browser compatible applications
• APIs: Developing RESTful APIs
• Architecture and design: MVC architecture, design patterns, and dependency injection
• Security: Authentication and authorization (JWT, OAuth2)
• Databases: Hands-on SQL with MySQL, PostgreSQL, or Oracle. This includes complex queries, joins, indexing, and query optimization.

Nice to Have

• Knowledge of NoSQL databases (MongoDB, DynamoDB)
• Exposure to Generative AI and LLM integration (OpenAI, Claude, Bedrock) in enterprise applications, including building RAG solutions with embeddings and vector databases.
• Familiarity with Spring AI or LangChain/LangChain4j, prompt engineering best practices, and streaming LLM responses to React UIs.
• Microservices architecture and messaging systems (Kafka, RabbitMQ)
• Cloud platforms (AWS, Azure, or GCP) and containerization (Docker, Kubernetes)
• Testing: JUnit and Mockito on the backend; Jest, React Testing Library, and Cypress or Playwright on the frontend

LA International is an award-winning partner of choice for many of the world's most influential companies and government organisations. Holding Enhanced Government Security Accreditation, we are recognised as the European market leader in the delivery of Security Cleared talent to organisations that demand the very highest levels of security, compliance and assurance.

A multiple award-winning organisation, having secured the prestigious Queens Award for Enterprise: International Trade over consecutive years.

We are committed to fostering an inclusive, equitable and accessible workplace where everyone feels valued and supported. We welcome applications from all individuals, regardless of background or identity, and we encourage candidates who may not meet every listed requirement to still apply. If you require any adjustments or support during the recruitment process, please let us know and we will work with you to ensure a fair and accessible experience.

Please Note: If a high volume of applications is received, only candidates shortlisted will be contacted.