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Insight International (UK) Ltd.

Java Full Stack Engineer

On site

London, United kingdom

Senior

Full Time

18-03-2026

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Skills

Communication Java JavaScript TypeScript SQL NoSQL Apache Kafka MongoDB PostgreSQL GitHub GitLab CI/CD DevOps Docker Kubernetes Monitoring Jenkins Scrum Problem-solving Attention to detail Architecture Programming Databases apache angular Analytical Skills Azure react AWS Software Development Postman Agile Junit Spring GCP Spring Boot Spring Security CI/CD Pipelines API Management Kafka Microservices GitHub Actions

Job Specifications

Role: Full Stack Developer

work from London office & Permanent role

5days/week onsite

Job Summary

We are seeking a highly skilled Full Stack Developer with strong experience in Java, Spring Boot, Kafka, and API Management platforms (Apigee) to build and support scalable, secure, and high-performance applications in the payments / banking domain. The ideal candidate will have hands-on experience with PayEdge or payment processing platforms, RESTful APIs, and modern front-end technologies.

Key Responsibilities

Backend / Microservices

Design, develop, and maintain Java-based microservices using Spring Boot
Implement RESTful APIs and integrate with internal and external systems
Build event-driven architectures using Apache Kafka (producers, consumers, streams)
Ensure high availability, scalability, and performance of services
Implement security using OAuth2, JWT, API keys, and role-based access

API Management & Integration

Design, publish, and manage APIs using API Gateway / Apigee
Configure API policies (security, throttling, caching, monitoring, transformation)
Manage API lifecycle, versioning, and documentation
Integrate APIs with PayEdge / payment gateways / core banking systems

Frontend / Full Stack

Develop responsive UI components using Angular / React / JavaScript / TypeScript
Integrate front-end applications with backend APIs
Ensure cross-browser compatibility and performance optimization

Payments / Banking Domain

Work on payment processing flows, transaction orchestration, and reconciliation
Support integrations with PayEdge, ACH, RTP, wire, or card-based payment systems
Ensure compliance with PCI-DSS, SOX, and regulatory standards

DevOps & Quality

Write unit, integration, and API tests (JUnit, Mockito, Postman)
Support CI/CD pipelines using Jenkins / GitHub Actions / GitLab
Containerize applications using Docker and deploy to Kubernetes / Cloud
Monitor and troubleshoot production issues

Required Skills & Qualifications

8+ years of experience in software development
Strong proficiency in Java (8/11/17) and Spring Boot
Hands-on experience with Kafka and asynchronous messaging
Experience with API Gateway solutions (Apigee preferred)
Strong knowledge of REST APIs, JSON, OpenAPI/Swagger
Experience with SQL / NoSQL databases (Oracle, PostgreSQL, MongoDB)
Frontend experience with Angular or React
Understanding of payment systems and financial services architecture

Preferred Qualifications

Experience with PayEdge or similar payment platforms
Cloud experience (AWS / Azure / GCP)
Knowledge of Reactive programming (WebFlux)
Experience with Spring Security
Exposure to event streaming, saga patterns, and distributed systems

Soft Skills

Strong problem-solving and analytical skills
Excellent communication and collaboration abilities
Ability to work in Agile / Scrum environments
Ownership mindset and attention to detail

Work Environment

Agile / Scrum delivery model
Fast-paced fintech or banking environment
High-availability, mission-critical systems

About the Company

We provide Software Development, Maintenance and Other Related IT Services, across spectrum, depending on individual client’s needs and dependability on us. Being a young and vibrant software solution company, we believe in harnessing the talent and experience of each member of our team to provide a unique flavor to our offerings within practical considerations and as per need and flexibility as expressed by our clients. We believe in working as a true partner and demonstrate transparency in all our dealings and conduct wi... Know more