Senior Java Engineer - High-Performance Microservices

Fynity Limited; Greater London; Hybrid; GBP 90,000 - 120,000; Full time

Benefits offered by this job

Annual 20% bonus

Hybrid work in London

Pension plan

Career progression

Job summary

Fynity Limited in London is seeking a Senior Java Engineer to design and build high‑performance, low‑latency systems for global financial clients. You’ll work on distributed architectures using Java 17+, Spring Boot, and modern CI/CD practices.

You will own development from design to production, collaborate with architects and client teams, implement asynchronous patterns with Kafka, integrate MongoDB, and contribute to code reviews and testing strategies.

Qualifications

• Strong Core Java knowledge and solid software engineering principles.
• Experience with high‑volume, low‑latency or distributed systems.
• Commercial Java experience with Spring/Spring Boot.
• Experience with Kafka or similar messaging platforms.
• No banking background required, but financial services exposure is a plus.

Responsibilities

• Design and develop high‑performance Java applications using modern Java and Spring Boot.
• Build scalable microservices and distributed, event‑driven systems.
• Develop asynchronous and message‑driven applications using Kafka or similar technologies.
• Work with MongoDB and other database technologies across high‑volume platforms.
• Design and develop REST APIs and contribute to wider system design.
• Solve complex engineering challenges around performance, latency, resilience and scalability.
• Collaborate with engineering, architecture and client teams throughout the development lifecycle.
• Take ownership of software from development and testing through to production.
• Contribute to code reviews, technical discussions and engineering best practices.
• Work with automated testing, TDD/BDD and modern CI/CD practices.

Skills

Core Java (Java 17+)

Spring Boot

Kafka

MongoDB

REST APIs

Distributed systems

CI/CD

TDD/BDD

Problem solving

Tools

None

Job description

Fynity Limited in London is seeking a Senior Java Engineer to design and build high‑performance, low‑latency systems for global financial clients. You’ll work on distributed architectures using Java 17+, Spring Boot, and modern CI/CD practices.

You will own development from design to production, collaborate with architects and client teams, implement asynchronous patterns with Kafka, integrate MongoDB, and contribute to code reviews and testing strategies.