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

Science Technician - Secondary School

Marchant Recruitment
Newham, Greater London

Location: East London Start Date: January 2026 Salary: Competitive, dependent on experience A well-run secondary school in East London is recruiting a Science Technician to join its suppor…

View Details
Posted 2026-01-07

Senior Product Manager - ML / Subscriptions Growth (Hiring Immediately)

spotify
London

Spotify’s mission is to unlock the potential of human creativity by giving a million creative artists the opportunity to live off their art and billions of fans the chance to enjoy and be passionate …

View Details
Posted 2026-03-27

Unqualified Senior Broker LBS-011

Southwark Council
Southwark, Greater London

Job Category : Social & Health Care Non-Qualified Location : Talfourd Place, Southwark Council Hours Per Week : 36.00 Start Date : Immediate Start Start Time : 09:00 End Time : 17:00 S…

View Details
Posted 2026-06-03

Marketing Manager (Mat Cover from September 2026)

MHP Group
London

MHP Group is the integrated communications agency built for the Networked Age – a world that’s increasingly connected, complex, polarised and activist. We lead the way in the application of behavi…

View Details
Posted 2026-03-28

.NET Developer

Noir
London

.NET Developer, .NET 10.0, C# 14 - Computer Gaming Company - London (Tech stack: .NET Developer, .NET 10.0, ASP.NET Core, C# 14, Azure, Angular 21, Vue.js, TypeScript, Multithreading, RESTful, ASP.NE…

View Details
Posted 2026-04-01

SEN Teaching Assistant - West Ealing, London Borough of...

Marchant Recruitment
London

Inclusive SEN Teaching Assistant Role in West Ealing – Making Learning Accessible for All A progressive and inclusive school in West Ealing , within the London Borough of Ealing, is seeking a …

View Details
Posted 2026-02-06

c£70,000++ - IP Filing & Docketing Specialist - London

London

Dawn Ellmore Employment have partnered with a leading law firm who are looking to recruit an experienced IP Filing & Docketing Specialist to join their growing patent prosecution team on a full-time,…

View Details
Posted 2026-02-27

Anatomical Pathology Technician SO1

Hackney Council
Hackney, Greater London

Job Category : Technical – Skilled Facilities Location :Hackney Service Centre, Hackney Council Hours Per Week : 36.00 Start Date : Immediate Start Start Time : 09:00 End Time :  17:15 …

View Details
Posted 2026-01-09

Science ECT - Core Science Mastery - Redbridge

Marchant Recruitment
Ilford, Greater London

ECT of Science – Specialist Induction for Core Science Mastery (KS3/4) – Redbridge An Outstanding rated secondary school in Redbridge is seeking an enthusiastic Early Career Teacher (ECT) of S…

View Details
Posted 2025-11-13

Music Teacher - Beautiful Independent School - Bexley

Marchant Recruitment
Bexley, Greater London

Forward-thinking Independent School in Bexley with a strong emphasis on digital literacy and innovation. • Full-time Music Teacher required from January 2026 • Well-equipped IT and computing fac…

View Details
Posted 2026-01-22