Rapid Application Engineer London ·

Internal Job Level: Associate

Reports to: Rapid Application Development Manager

Job Overview

In this role you will be working with the Product, Infrastructure, QA, and Operations teams to solve complex problems at speed. Unlike our Low Latency team who build the exchange engine itself, the RAD (Rapid Application Development) team lives at the intersection of troubleshooting, innovation, and operational efficiency. You’ll be investigating the toughest production issues, validating new trading technology approaches through rapid prototyping, and building the internal tools and test frameworks that keep Aquis running smoothly. You’ll be part of a small, high-impact team that combines detective work with creative engineering. One day you might help investigate a performance anomaly in one of our trading workflows; the next, you'll be building a utility to help QA stress-test a new feature or writing scripts to analyse performance bottlenecks. You're starting a journey where problems are often ambiguous, priorities shift quickly, and learning from more experienced colleagues will accelerate your growth significantly.

To succeed as a Mid-Level RAD Engineer, you will be a proponent of agile principles and modern software best practices. You can produce clean, well-tested code and collaborate effectively with the development team. Ideally, you will have worked in environments where code reliability and performance matter, whether that's systems programming, embedded systems, or previous experience in critical infrastructure. This role will develop your operational mindset: understanding not just what systems do, but why they fail and how to prevent it.

Responsibilities and Duties

• Investigate production issues and platform behaviour: Help diagnose system problems with guidance from senior engineers; work to create reproducible test cases and diagnostic frameworks that validate root causes; learn to identify patterns and root causes; document findings clearly so the broader team can learn.
• Support rapid prototyping efforts: Implement features and approaches in POC code; write clean, testable code even under time pressure; validate technical approaches and gather feedback for the Product team.
• Build tools and utilities for internal teams: Develop test utilities, diagnostic scripts and monitoring tools that help Operations and QA teams work more effectively and validate fixes reliably.
• Code, test, integrate, and document software: Produce high-quality code with appropriate test coverage; participate in code review; maintain clear documentation and commit messages.
• Learn the platform and systems architecture: Actively invest in understanding how Aquis' market data, order matching, and trading workflows operate; build mental models of system behaviour so you can spot anomalies.
• Apply computer science fundamentals: Use your understanding of algorithms, data structures, networking, and systems design to break down complex problems.
• Escalate appropriately and ask for guidance: Work independently but recognize when issues need senior involvement; leverage your team's expertise.

Skills and Experience

Essential

• 4+ years professional C++ development experience (C++11 or later), in any domain, e.g. finance, systems, embedded, or other high-performance contexts.
• Comfortable working with core networking concepts: TCP, UDP, multicast.
• Linux experience: Able to navigate Linux systems, use common debugging tools, and understand basic system concepts (processes, file descriptors, memory, etc.).
• Python, Git, and SQL: Comfortable writing scripts, using version control, and querying data.
• Kanban and CI/CD: Comfortable with Kanban workflow, Jira, continuous integration, and rapid iteration.
• Writing well-tested code and creating reproduction environments: Able to write effective test cases, establish diagnostic frameworks, and set up reproducible environments that help isolate and validate fixes for complex issues.
• Analytical mindset: You enjoy investigating "why" something happened and can break down complex systems into understandable pieces.
• A genuine desire to learn trading technology: Curiosity about how financial markets work and how exchange technology fits into that ecosystem.
• Team player mentality: You collaborate well, give and receive feedback gracefully, and take initiative without needing constant direction.
• Comfortable using AI tools in development: Familiar with LLMs, coding assistants, and AI-powered tools for writing code, debugging, generating tests, and exploring solutions.

Desired

• Real-time or event-driven systems: Any experience where latency, throughput, or deterministic behaviour matters (e.g., gaming engines, robotics, HFT platforms, telecommunications).
• Boost libraries: Exposure to or experience with Boost (threading, networking, utilities, etc.).
• Capital markets protocols: Familiarity with FIX or other exchange-related protocols or standards.
• Performance analysis: Experience with profiling, optimization, or working on latency-sensitive code.
• QuestDB or Dolt: Time-series or version-controlled database experience.
• Open-source contributions, side projects, or competitive programming: Evidence that you pursue engineering challenges outside of work and enjoy problem-solving for its own sake.
• Shell scripting (Bash): For automation and system-level tasks.
• Docker/containers: Growing relevance for modern development workflows.

Mindset and Methodology

• Intellectually curious: You're genuinely interested in understanding how systems work, why they fail, and how to make them better. You ask good questions and learn from both successes and failures.
• Delivers incrementally: You understand that done is better than perfect. You can deliver a working MVP, validate it with stakeholders, and iterate based on feedback.
• Self-directed learner: You take ownership of understanding the Aquis platform and trading technology. You read code, ask questions, and invest in deep learning without constant prompting.
• Good team player: You collaborate well across teams, take feedback constructively, and help colleagues succeed.
• Autonomous but seeks guidance wisely: You work independently on well-scoped tasks but recognize when issues need escalation or expertise beyond your current level.
• Comfortable with production operations: You understand that code runs in production with real traders depending on it. You think about reliability, observability, and operational concerns, not just features.
• Growth mindset: You're early in your career relative to senior engineers, and you're excited about the opportunity to learn from experienced colleagues and grow your skillset.

About Aquis Exchange

Aquis Exchange(“Aquis”) is Europe’s challenger exchange, creating better markets for a modern economy. Aquis has market-leading technology and innovative rules for trading, and offers primary listings and secondary trading of equities, along with global licensing of proprietary technology. Aquis consists of four divisions: Aquis Markets operates lit and dark order books, covering 16 European markets. For its lit books, Aquis uses a subscription pricing model which works by charging users according to the message traffic they generate, rather than a percentage of the value of each stock that they trade. Aquis Technologies is the software and technology division of Aquis. It focuses on building better markets via the creation and licensing of cutting-edge, cost-effective exchange infrastructure technology and services, including matching engine and trade surveillance solutions. Aquis Stock Exchange (“AQSE”) is a stock market providing primary and secondary markets for equity securities. It is authorised as a Recognised Investment Exchange, which allows it to operate a regulated listings venue. The AQSE Growth Market is divided into two segments ‘Access’ and ‘Apex'; the Access market focuses on earlier stage growth companies, while Apex is the intended market for larger, more established businesses. Aquis Data generates revenue from the sale of data derived from Aquis Markets and Aquis Stock Exchange to non-Member market participants. Aquis is authorised and regulated by the UK Financial Conduct Authority and France's Autorité de contrôle prudentiel et de résolution and L’Autorité des marchés financiers to operate Multilateral Trading Facility businesses in the UK & Switzerland markets and in EU27 markets, respectively. Aquis is part of SIX: the provider and operator of stable and efficient infrastructure for the Swiss and Spanish financial centres.

Our Culture

At Aquis, we’re proud of our culture - one built on trust, collaboration, and accountability. We work fast, support one another, and share responsibility for both our successes and our lessons learned. Our values guide how we work every day: Win as One – We collaborate, share knowledge, and celebrate collective success. Disrupt Positively – We challenge the status quo and look for smarter, better ways to do things. Find Joy – We take pride in our work and enjoy what we do, even when it’s challenging. Act with Honour – We do the right thing, with integrity and respect for others. You’ll join a supportive, ambitious, and diverse team where ideas are encouraged and innovation is part of our DNA. We recruit talented people from all walks of life and empower them to make an impact. If our values resonate with you, Aquis could be the ideal place to grow your career.

The statements included in this job description are intended to describe the general nature and level of work being performed by people assigned to this job. They are not intended to be an exhaustive list of all responsibilities, duties and skills required.

Equal opportunities at Aquis Exchange. We are an equal-opportunities employer. All applicants will receive consideration for employment without regard to race, gender, colour, religion, sex, sexual orientation, gender identity, national origin, disability or veteran status.