Systems Software Engineer - Core IP Security | Quant Finance Research Firm

Techfellow Limited; Greater London; Hybrid; GBP 135,000 - 225,000; Full time

Benefits offered by this job

Office-led with 3 days remote permonth

Job summary

Techfellow Limited, a leading quantitative research and technology firm in London, seeks a systems-focused software engineer to design, build and operate proprietary backend services and internal platforms. You’ll work across Linux infrastructure, automation and APIs, with exposure to secure infrastructure concepts.

You will own testing, deployment and production support across languages such as C#/.NET, Python, Go and Rust, while improving reliability and performance in a high-security

Qualifications

• Strong programming fundamentals in at least one of C#, Java, Python, Go, Rust or C++, with evidence of building substantial production software.
• Hands‑on Linux engineering experience with infrastructure automation.
• Experience owning software through testing, CI/CD, deployment and production support.
• Exposure to authentication, IAM, secure infrastructure concepts is a plus.

Responsibilities

• Design, build and operate proprietary backend services and internal platforms.
• Develop REST APIs across languages including C#/.NET, Python, Go and Rust.
• Automate Linux server provisioning and administration using Ansible and CI/CD tooling.
• Own testing, deployment, monitoring and production troubleshooting with a disciplined approach.
• Take end-to-end ownership across the software and infrastructure stack.
• Assess existing services and simplify or rebuild components for better engineering outcomes.

Skills

C#

Java

Python

Go

Rust

C++

REST API design

Linux

Ansible

CI/CD

Tools

Ansible

CI/CD tooling

REST API

Job description

[Up to c. £225k Comp Package | Office-Led Working - 3 Days Remote Per Month]

Role Overview

We’re representing a highly successful quantitative research and technology firm operating one of the most sophisticated proprietary engineering environments in the financial markets. The organisation builds a significant proportion of its technology internally, supporting complex research and production workloads where reliability, performance and protection of valuable intellectual property are critical. This team sits at the intersection of software, infrastructure and security, developing bespoke platforms rather than relying heavily on external products.

This is fundamentally a systems-focused software engineering role rather than a traditional cyber-security position. You’ll join a small, highly technical team responsible for building and operating proprietary services across backend development, Linux infrastructure, automation, APIs and underlying server hardware. Engineers are expected to investigate problems deeply, own systems throughout their lifecycle and improve or rebuild components where a better engineering approach exists, while gaining exposure to areas including IAM, MFA, cryptography and secure infrastructure...

Key Responsibilities

• Design, build and operate proprietary backend services and internal platforms supporting highly sensitive research, intellectual-property and production workflows


• Develop production-grade services and REST APIs across languages including C#/.NET, Python, Go and Rust, with opportunities to contribute increasingly to Rust-based systems


• Automate Linux server provisioning, configuration and administration using Ansible and CI/CD tooling, including bootstrapping environments from bare-metal infrastructure


• Engineer concurrent, highly available and fault-tolerant systems where correctness, uptime, observability and predictable behaviour are important operational requirements


• Take end-to-end ownership across the software and infrastructure stack, including interaction with physical server hardware and management interfaces such as iLO


• Build and maintain systems integrations covering areas such as authentication, MFA, identity functionality, access controls and other internally developed security capabilities


• Own testing, deployment, monitoring and production troubleshooting, investigating anomalies thoroughly rather than treating operational issues as isolated incidents


• Assess existing services and workflows critically, simplifying, replacing or rebuilding components where architectural or engineering improvements would materially strengthen the platform

What You’ll Bring…

• Typically around 4-10 years of professional software engineering experience, ideally working on systems, infrastructure platforms, backend services or other technically demanding production environments


• Strong programming fundamentals in at least one of C#, Java, Python, Go, Rust or C++, with evidence of building substantial production software rather than primarily scripting or configuration work


• Hands‑on Linux engineering experience alongside Ansible or comparable infrastructure automation, with confidence working below the application layer and understanding how systems are provisioned and operated


• Strong understanding of concurrency, distributed or highly available systems, REST API design and the engineering trade-offs involved in building reliable production services


• Experience owning software through testing, CI/CD, deployment, observability and live production support, with a disciplined approach to diagnosing complex or unexpected system behaviour


• Evidence of broad technical curiosity and end-to-end ownership, including a willingness to investigate infrastructure, networking, operating‑system or hardware‑level issues beyond the immediate application boundary


• (Preferred) Experience building proprietary internal platforms, infrastructure tooling or systems integrations within quantitative finance, trading, technology, research or another high-performance engineering environment


• (Preferred) Exposure to IAM, MFA, PKI, cryptography, secure infrastructure or similar security concepts, although deep cyber-security or AppSec experience is not required