[Hiring] Senior Frontend Engineer @Reactive Markets

Role Description

We're looking for a senior full-stack engineer to build the trading platform our clients use every day. Despite the "frontend" name, this is not a UI-only role — our Frontend team works across the whole application stack in TypeScript and Rust, from the trader-facing interfaces down to the services behind them.

This is a senior individual contributor role for someone who takes on the hardest problems and delivers them under their own steam. You'll own complex, ambiguous, performance-critical work end-to-end — designed, built, tested, deployed, and supported in production.

You lead through code, craft, and mentoring, setting the technical example the rest of the team calibrates to. This is not a role where you write code and throw it over a wall: our engineers own the full lifecycle, and when something breaks, you're part of the team that investigates and fixes it.

Occasional hours outside the normal working day are required for production releases, scheduled maintenance windows, and Level 3 support during critical incidents. We keep this to a minimum and recognise the commitment — but owning a production trading platform means being there when it matters.

What You'll Work On

• Complex full-stack features in TypeScript and Rust — from trader-facing interfaces to the application services behind them
• Real-time market-data presentation and high-throughput, low-latency application code across FX, Equities, and Cryptocurrency
• React and reactive state management (RX, MobX, or similar) for demanding, data-dense trading interfaces
• Distributed systems and real-time data over REST, WebSockets, and network protocols
• Architecture and solution design for the hardest technical problems the team faces
• Observability and monitoring — dashboards, alerting, and metrics that make frontend behaviour visible
• Production systems that handle real money — reliability is not optional

Qualifications

• Strong full-stack engineering ability with deep TypeScript / JavaScript (ES6+) (5+ years)
• Solid experience with React and reactive state management (RX, MobX, or similar)
• Real working ability in Rust — it's part of our stack and not optional at this level
• Strong grasp of distributed systems, API design, and real-time data (REST, WebSockets, network protocols such as TCP/UDP and binary protocols)
• Comfortable reasoning about architecture and making defensible technical trade-offs
• Python for scripting, automation, and tooling is a bonus
• Git and Linux fundamentals
• Experience in financial services or trading technology is a plus but not essential

Requirements

• You ship. You're delivery-focused — you iterate, you improve, you get things into production
• You run with things. Give you an ambiguous, complex problem and you drive it to done without being managed through it
• You have range. You're not just strong in the familiar parts of the stack — you pick up the unfamiliar and hold your own on the hardest work
• You own it. When you build something, you take responsibility for its behaviour in production
• You raise the bar. You review peers' work thoughtfully, mentor the engineers around you through the craft
• You write things down. Documentation is not an afterthought — it's how we scale knowledge across a distributed team
• You communicate. Clear, proactive communication — especially when things go wrong — is essential
• You embrace AI tooling. We use AI tools (Claude, Gemini) to amplify our engineering capability

Benefits

• Real problems — trading systems where performance is measured in microseconds, not user clicks
• An excellent team — senior engineers who care about craft, collaborate openly, and hold each other to high standards
• Ownership — small teams, clear accountability, direct impact on the platform and our clients
• Competitive package — up to 30 days leave + bank holidays, private health insurance, pension, life insurance, dental/optical cashback, cycle to work, socials and offsites
• Remote-friendly — work from home with flexibility
• Sustainable pace — we work hard, but we don't burn people out
• Growth — career progression to senior roles, performance specialisation, or technical leadership

Our Hiring Process

• Stage 1: Initial Conversation with Talent Acquisition (Video call, ~30-45 minutes)
• Stage 2: Hiring Manager Conversation with the relevant team lead or hiring manager (Video call, ~60 minutes)
• Stage 3: Technical Interview with two members of the relevant engineering team (Video call, interactive session, ~60 minutes)

How to Apply

Please apply directly via this job posting — all applications, including those submitted via LinkedIn, are managed through our applicant tracking system.

Right to Work

Candidates must have the existing right to work in the UK. We are not currently able to offer visa sponsorship for this role.

Equal Opportunities

Reactive Markets is an equal opportunities employer. We welcome applications from all qualified candidates regardless of age, disability, gender reassignment, marriage or civil partnership, pregnancy or maternity, race, religion or belief, sex, or sexual orientation.

Reasonable Adjustments

If you need any adjustments or support during the application or interview process, please let us know — we're happy to accommodate.

Data Protection

By applying, you consent to Reactive Markets processing your personal data for recruitment purposes, in line with our privacy policy.