Contract Senior Java Developer - Data

Quant Capital
London

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
Posted 2026-03-12

Recommended Jobs

COS E-Commerce Controller Sales and Planning

COS
London

Job Description LOCATION: London FUNCTION: Controlling TEAM: EU Regional MANAGER: Regional Brand Controller KPIs: Sales and WH Planning Accuracy ABOUT THE ROLE: Drive sales bu…

View Details
Posted 2026-05-27

Service Advisor

Cricklewood, Greater London

About the position The successful candidate for our Service Advisor position will have previous experience in a similar role and proven customer service skills. You will be welcomed int…

View Details
Posted 2025-09-10

Part-time Afterschool Nanny in Balham, Job ID J20418

Little Ones UK Ltd
Balham, Greater London

A lovely family based in Balham is looking for a reliable, professional and caring Afterschool Nanny to care for their two school-aged children. The ideal candidate will be someone with SEN experienc…

View Details
Posted 2026-03-12

Reservations Agent

Millennium Hotel and Resorts UK
London

The Copthorne Tara Hotel London Kensington is looking for Reservations Agent to be the first point of contact for guests and other stakeholders, offering friendly and professional service and to ente…

View Details
Posted 2026-04-24

Teaching Assistant - Outstanding Secondary School, Lambeth

Marchant Recruitment
London

Teaching Assistant – Outstanding Secondary School, Lambeth (January Start) School Information This Outstanding Ofsted-rated secondary school in Lambeth is committed to inclusive education and hi…

View Details
Posted 2026-01-10

Junior Java Software Engineer - Data Engineering

Quant Capital
London

Java Software Engineer – Data Engineering Up to £70,000 + bonus and benefits 4:1 hybrid in office – City of London Quant Capital is hiring for a small, high-performing market maker in L…

View Details
Posted 2026-02-18

Fire & Security Service Engineer

Banham
London

Join London's leading and most prestigious Security company as a Fire and Security Service Engineer. Steeped in history, innovation and excellence, Banham is seeking a highly skilled, experienced and…

View Details
Posted 2025-09-30

Year 3 Teacher - Lambeth

Marchant Recruitment
London

An Outstanding Lambeth primary is recruiting a reflective and creative Year 3 Teacher to join Key Stage 2 on a Full-Time basis from January 2026. The successful Year 3 Teacher will take part in colla…

View Details
Posted 2025-11-06

Europe Marketing Lead

OSOME
London

We're Osome - an international fintech startup making the lives of entrepreneurs easier. We help thousands of businesses kick admin, accounting and bookkeeping out of their day-to-day, so they can sp…

View Details
Posted 2026-04-30

Attendance Officer - Outstanding Mixed School in Croydon

Marchant Recruitment
Croydon, Greater London

Attendance Officer – Outstanding Mixed School in Croydon Location: Croydon Start Date: January 2026 Contract Type: Full-time, Permanent Salary: Competitive, dependent on experience …

View Details
Posted 2025-12-16