Founding Engineer

Jobs in JS; City Of London; Hybrid; GBP 140,000 - 200,000; Full time

Job summary

Jobs in JS seeks a Founding Engineer to own end-to-end delivery of high-performance systems, architecting from scratch and shipping fault-tolerant, scalable software. You will work autonomously in a flat organisation, setting engineering standards and creating reusable tools while guiding architecture and implementation across the stack.

You will operate with full ownership of realising complex ideas into production systems, spanning from design through deployment, security, data integrity and

Qualifications

• Strong fundamentals in algorithms, system architecture, concurrency and distributed systems.
• Experience delivering high-throughput, latency-sensitive systems.
• Ability to own end-to-end design and delivery from idea to production.

Responsibilities

• Build & refine core platform foundations from the ground up.
• Own solutions end-to-end from problem definition to deployment and production support.
• Operate in a flat structure with direct accountability for core system delivery.
• Set pristine engineering standards and automated validation.
• Identify bottlenecks and build reusable tools to scale the engineering environment.

Skills

Polyglot programming

High autonomy

System design

Concurrency & distributed systems

Python

C++

Java

TypeScript

Performance optimization

Job description

About the Opportunity

We are partnering with a tech company founded by industry veterans with deep expertise in enterprise architecture and quantitative systems. The company is establishing its founding engineering team to design, build, and scale their core platform from the ground up, delivering high-performance solutions for complex data processing and mission-critical workflows.

The Role

We are seeking an exceptional Founding Engineer, a hands-on technical expert who takes complete ownership of delivering complex systems to the highest standard, end-to-end.

You will operate with high individual autonomy, taking raw, complex business or quantitative ideas and turning them into fault-tolerant, high-throughput systems.

You will own the total realisation of complex ideas into working solutions, architecting systems from scratch, refactoring paradigms where needed, creating high-performance code across the tech stack, and taking full responsibility for end-to-end execution.

Key Responsibilities & Operating Principles

• Build & Refine Core Platform Foundations: Drive the architectural vision and hands-on execution from the ground up, designing and building the foundational systems that power our mission-critical solutions.
  

• End-to-End Delivery & Ownership: Own solutions across their entire lifecycle - from initial problem definition and architecture down to deployment, system security, data integrity, operational resilience, and production support.
  

• Flat Structure & High Accountability: Work in a streamlined, non-hierarchical environment with direct access to decision-makers and domain experts, taking direct accountability for core system delivery.
  

• Set the Technical Bar: Establish pristine engineering standards, clean system design, automated validation, and operational patterns that will define the team culture as the company scales.
  

• Foundational Scale & Leverage: Identify structural friction, optimise system bottlenecks, and build reusable tools that elevate the execution capacity of the whole engineering environment.
  

Technical Capabilities & Agnostic Mindset

Languages, frameworks, and storage paradigms are simply tools chosen for the specific problem at hand. Adaptability, fast learning, and deep computer science fundamentals are valued far above specialisation in any single framework.

• Broad Computing Fundamentals: Strong foundations in algorithms, system architecture, concurrency, distributed systems, and performance tuning.
  

• Low-Latency & High-Throughput Systems: Deep understanding of performance at the hardware level (memory layout and allocation, garbage collection, lock-free concurrency, binary serialisation and efficient I/O), with experience building systems that process millions of events per second with predictable latency.
  

• Polyglot Execution: Fluid ability to work across multiple languages and paradigms (e.g., Python, C++, Java, TypeScript) as required by system demands.
  

• Modern Data Ecosystems: Experience working across diverse, modern data paradigms, ranging from real-time analytics and time-series pipelines to big data processing engines, memory-mapped stores, and machine learning integration workflows.
  

• Production Operations: Hands-on capability deploying and operating latency-sensitive production systems, from bare-metal and OS-level tuning to cloud-native infrastructure, containerisation, automated testing, continuous delivery pipelines, and system monitoring.
  

What You Bring

1. Versatile, Tech-Agnostic Mindset: You absorb new languages, frameworks, and domain concepts effortlessly. You choose the right tool for the job based on performance, scalability, and complexity rather than habit.
   

2. High Autonomy & Problem-Solving: You don't need ticket queues to execute. You see what needs to be built, design the solution, and ship it.
   

3. Exceptional Delivery Standards: High personal standards for code clarity, system robustness, and architectural elegance.
   

4. Strong Interpersonal & Communication Skills: Excellent verbal and written communication. You communicate clearly with technical peers and executive leadership alike, translating raw requirements into technical execution without friction.
   

5. Judgement, Curiosity & Continuous Learning: Relentlessly curious and fast to adapt. In an era of rapid AI evolution and shifting tech stacks, you rely on strong engineering first principles and sound technical judgement.
   

6. Financial Markets & Data Expertise (strongly preferred): Prior experience in quantitative finance, capital markets or hedge funds, with hands-on exposure to high-volume financial data pipelines.
   

Location & Work Pattern

• Hybrid Model: Flexible, distributed working model, with as-needed on-site presence.
  

• Key Hubs: London, Cambridge, Athens, New York.