Senior Software Engineer (Backend & Infrastructure)

Prop League; Greater London; Hybrid; GBP 110,000 - 160,000; Full time

Benefits offered by this job

Room for technical leadership up to CT

Hybrid working in London

25 days holiday + UK holidays

Founding team ownership

Pension

Job summary

Prop League is seeking a senior backend engineer to own live trading platform systems end-to-end. You will build and operate integrations, data pipelines, and secure infrastructure that traders rely on daily.

You will lead design reviews, implement robust reconciliation, and ensure security best practices across services, APIs, and databases in a hybrid London-based setup.

Qualifications

• Experience owning production backend systems end to end, including on-call responsibilities.
• Strong TypeScript and Node.js, with depth in at least one backend ecosystem.
• Deep PostgreSQL experience: schema design, migrations, performance and access control.
• Production AWS experience: containers, IAM, KMS and VPC networking, managed as code.
• Familiarity with trading-platform or brokerage APIs (Tradovate, ProjectX or Rithmic).

Responsibilities

• Build and run trading-platform integrations: long-running real-time connections and data capture that tolerate reconnects and retries.
• Own the end-to-end data path from fills to results with reconciliation and verification.
• Run production on AWS with infrastructure-as-code and robust monitoring.
• Lead incident response, on-call readiness, and blameless postmortems.
• Own platform security: encryption, key management, least-privilege access and reviews.
• Maintain PostgreSQL performance: schema design, migrations, backups and recovery drills.
• Review code with emphasis on clarity and simplicity, across the stack.

Skills

Production backend systems end-to-end

TypeScript

Node.js

PostgreSQL

Python

Security

Idempotency & reconciliation

Trading-platform APIs

Trading interest

Tools

AWS

GitHub Actions

Tradovate API

ProjectX API

Rithmic API

NinjaTrader

Job description

\"Traders bring the performance. We build everything beneath it.\"

About Prop League

Trading is one of the most competitive pursuits in the world, and yet one of the least visible. Thousands of funded traders put real firms' capital and real nerve on the line every day, but the best of them can't prove it beyond screenshots. P&L resets when an account closes, results are scattered across firms and platforms, and real talent disappears into the noise.

The role

Every number on a Prop League table has to be right: through the market open, a dropped connection, or a platform outage. Traders compete for those numbers, argue over them and stake their reputation on them.

You will build everything underneath them: the integrations, the data pipelines, the infrastructure and its security. The work is half building, half running. We're a small, senior team, so the systems you design are the ones that ship, and your decisions show up in the product every trading day.

This role is for someone who wants to own a live system end to end, cares that every number is right, and leaves a codebase simpler than they found it.

What you will do

• Build and run trading-platform integrations: long-running real-time connections and scheduled data capture that stay correct through reconnects, retries, gaps and duplicates.
• Own the path from fills to results: reconciliation and verification, so every number holds up to scrutiny from traders and prop firms.
• Run production on AWS: ECS, KMS and networking defined as code, with monitoring that spots problems before traders do.
• Lead incident response: on-call, runbooks and blameless postmortems.
• Own platform security: credential encryption and key management, least-privilege access and security reviews.
• Keep PostgreSQL fast and safe as we grow: schema design, migrations, query performance, backups and recovery drills.
• Raise the bar on every change: review code with care, whoever or whatever wrote it, and simplify wherever complexity has crept in.

What we are looking for

We care more about what you've built and run than how many years you've been doing it.

• You've owned production backend systems end to end, including being on call for them.
• Strong TypeScript and Node.js. Depth in one backend ecosystem matters more than a long list of languages.
• Deep PostgreSQL experience: schema design, migrations, performance and access control.
• Production AWS experience: containers, IAM, KMS and VPC networking, managed as code.
• You've kept long-running services correct through disconnects, retries and restarts, and you think in idempotency and reconciliation.
• You use AI coding tools critically, and can say concretely where they help and where they fall short.
• You think security-first, write clearly, and stay steady when production breaks.
• Experience with trading-platform or brokerage APIs, especially Tradovate, ProjectX or Rithmic.
• An interest in trading, or experience as a trader yourself. If you're new to futures, we'll teach you the basics.
• Security or compliance work in a regulated setting (SOC 2, ISO 27001, UK GDPR).
• Python, for data tooling and verification.

Our stack

TypeScript, Node.js, Next.js, React, PostgreSQL and GitHub Actions. On AWS: ECS on Fargate, ECR, EC2, KMS, IAM, VPC and CloudWatch, managed with the AWS CDK. Integrations: Tradovate (NinjaTrader), ProjectX and Rithmic.

What success looks like

• 30 days: you know the platform end to end, you've shipped to production, and you're on call for the systems you know.
• 60 days: you own a core part of our data infrastructure, with the observability to prove it's healthy.
• 90 days: you're shaping the platform roadmap and the engineering standards we build to.

Why join Prop League

• Room to grow into technical leadership, up to CTO, as the team grows.
• Hybrid working, with regular days in London and flexible hours around the trading week.
• 25 days' holiday plus UK bank holidays and a workplace pension.
• Real ownership of a live platform at a defining stage, in an industry that's growing fast.
• Join as part of the founding team, and help shape how Prop League builds and transforms the industry from the start.

You will need the right to work in the UK; we can't sponsor visas for this role. We welcome applicants from every background, and if you need adjustments at any stage, tell us and we'll make them. We're not accepting agency CVs for this role.

Prop League will never ask candidates for money, bank details or trading-account logins during hiring. If a message claiming to be from us does, don't respond, and report it to [e-mail].