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Contract Senior Java Developer

Contract Senior Java Developer

On site

London, United kingdom

£ 700 /day

Senior

Freelance

12-03-2026

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Skills

Python Java SQL Data Engineering PostgreSQL CI/CD Monitoring git AWS

Job Specifications

Contract Senior Java Developer – Data

Up to £700 per day Outside IR35 (6 month rolling)

In office – City of London

Quant Capital is hiring for a small, high-performing market maker in London. This is a junior-to-mid role focused primarily on Java development, with a secondary responsibility owning straightforward Python ETL/data ingestion into AWS and PostgreSQL. This is a growing team focused on data ingestion and building tooling for the wider firm.

What you’ll do:

Build and enhance Java backend services (APIs, batch jobs, integrations) used across the business
Write clean, testable code with solid engineering discipline (testing, code review, debugging, production support)
Maintain and extend Python-based ingestion/ETL (pragmatic plumbing, not heavy data engineering)
Work with PostgreSQL (schemas, migrations, performant queries, data validation)
Improve service reliability: monitoring/logging, sensible alerting, and predictable deployments via CI/CD

Tech:

Java (primary), Python (secondary), AWS, PostgreSQL + Git, CI/CD, logging/monitoring

What they want:

10+ years of experience building production systems (or equivalent ability)
Strong Java fundamentals (OO design, APIs/services, concurrency basics, testing)
Some UI development
Comfortable with SQL/PostgreSQL
Some Python experience (enough to manage and improve existing ETL/ingestion)

Nice to have

Any finance or markets exposure
Familiarity with common AWS patterns for running services and pipelines

Why this role

Broader scope than pure app dev: you’ll understand the data feeding the platform
Lean team, high impact, strong growth runway

About the Company

Executive Search and Recruitment to the Quantitative Trading and Financial Technology space. We provide a discrete search capability for the best known and most prestigious Hedge Funds & Prop Trading firms in the world. Our specialized experience, market knowledge, extensive network, and commitment to client service ensure that every search is conducted effectively. Quant Capital has been the Recruitment Partner to the Fintech50 for many years. Our goal is to be recognised as a partner to the most interesting trading and... Know more