Java Software Engineer

Quant Capital; Greater London; On-site; GBP 90,000 - 130,000; Full time

Job summary

Quant Capital in London is seeking a mid-to-senior Java developer to build and enhance backend services, APIs, batch jobs and system integrations. You will own the data ingestion layer and contribute to tool building for the wider firm.

The role requires 10+ years producing production systems, strong SQL/PostgreSQL, and at least some Python for ETL work. A lean, high-impact team offers growth and exposure to AWS patterns and data-driven platforms.

Qualifications

• 10+ years of experience building production systems.
• Strong SQL and PostgreSQL skills.
• Some Python experience to manage and improve ETL/integration.
• Ability to work in a small, high-performance market-making team.

Responsibilities

• Build and enhance Java backend services (APIs, batch jobs, integrations).
• Write clean, testable code with solid engineering discipline.
• Maintain Python-based ingestion/ETL and AWS-based data flows.
• Work with PostgreSQL schemas, migrations, and data validation.
• Improve service reliability with monitoring, logging, and CI/CD deployments.

Skills

Java

Backend development

SQL / PostgreSQL

Python

Tools

PostgreSQL

AWS

CI/CD

Job description

Quant Capital is hiring for a small, high-performing market maker in London. This is a Mid-to-Senior 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:

What they want:

• 10+ years of experience building production systems (or equivalent ability)
• 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