{"id":27219,"url":"https://alion.io/job/reactive-markets-senior-frontend-engineer","title":"Senior Frontend Engineer","company":{"id":7325,"name":"Reactive Markets","domain":"reactivemarkets.com","url":"https://alion.io/company/reactive-markets","size_band":"51-200","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Ashby","truth_index":null},"role":"Frontend","role_family":"Frontend","seniority":"senior","employment_type":"full_time","work_mode":"remote","remote_scope":"stated_countries","remote_scope_basis":"posting_text","remote_working_hours":null,"hiring_geo_confidence":"structured","locations":[],"countries":[],"hiring_countries":["GB"],"hiring_countries_total":1,"salary":null,"salary_estimate":{"min_usd":62000,"max_usd":127000,"period":"year","method":"role_seniority_country_cell","sample_n":15},"experience_years_min":null,"visa_sponsorship":true,"relocation_package":false,"has_equity":false,"technologies":[{"name":"C++","optional":false},{"name":"Go","optional":false},{"name":"JavaScript","optional":false},{"name":"React.js","optional":false},{"name":"Rest API","optional":false},{"name":"Rust","optional":false},{"name":"TypeScript","optional":false},{"name":"WebSockets","optional":false},{"name":"Claude","optional":true},{"name":"Git","optional":true},{"name":"Linux","optional":true},{"name":"Python","optional":true}],"status":"live","first_seen_at":"2026-07-22T14:58:07Z","employer_posted_date":"2026-10-19","last_verified_at":"2026-10-24T00:54:05Z","board_verified":true,"closed_at":null,"days_open":93,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":93},"description":"Senior Frontend Engineer\nRemote (UK-based) | Full-Time\nAbout Us\nReactive Markets is the 2026 OTC Trading Platform of the Year (Risk.net). Our network handles over $75 billion in daily trading volumes across FX, Equities, and Cryptocurrency, connecting 60+ of the world's leading liquidity providers.\nWe build trading systems that operate at the edge of what's technically possible - where nanoseconds matter and a dropped message costs real money. Our engineering team is small, senior, and deeply invested in the craft of building cutting edge, reliable, high-performance systems.\nThe Role\nWe'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. It's distinct from our Backend team, who own the low-latency C++/Go trading engine.\nThis 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.\nOccasional 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.\nWhat You'll Work On\nComplex full-stack features in TypeScript and Rust - from trader-facing interfaces to the application services behind them\n\nReal-time market-data presentation and high-throughput, low-latency application code across FX, Equities, and Cryptocurrency\n\nReact and reactive state management (RX, MobX, or similar) for demanding, data-dense trading interfaces\n\nDistributed systems and real-time data over REST, WebSockets, and network protocols\n\nArchitecture and solution design for the hardest technical problems the team faces\n\nObservability and monitoring - dashboards, alerting, and metrics that make frontend behaviour visible\n\nProduction systems that handle real money - reliability is not optional\n\nWhat We Need\nTechnical:\nStrong full-stack engineering ability with deep TypeScript / JavaScript (ES6+) (5+ years)\n\nSolid experience with React and reactive state management (RX, MobX, or similar)\n\nWorking knowledge of Rust, or the clear appetite and ability to get there - it's part of our stack\n\nStrong grasp of distributed systems, API design, and real-time data (REST, WebSockets, network protocols such as TCP/UDP and binary protocols)\n\nComfortable reasoning about architecture and making defensible technical trade-offs\n\nPython for scripting, automation, and tooling is a bonus\n\nGit and Linux fundamentals\n\nExperience in financial services or trading technology is a plus but not essential\n\nHow you work:\nYou ship. You're delivery-focused - you iterate, you improve, you get things into production\n\nYou run with things. Give you an ambiguous, complex problem and you drive it to done without being managed through it. Senior here means trusted, not just experienced\n\nYou 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\n\nYou own it. When you build something, you take responsibility for its behaviour in production. You respond to incidents (15-minute acknowledgement SLA during working hours), investigate issues, and close the loop\n\nYou raise the bar. You review peers' work thoughtfully, mentor the engineers around you through the craft, and set a standard others calibrate to\n\nYou write things down. Documentation is not an afterthought - it's how we scale knowledge across a distributed team. If it's not written down, it doesn't exist\n\nYou communicate. We're a distributed team across multiple time zones. Clear, proactive communication - especially when things go wrong - is essential\n\nYou embrace AI tooling. We use AI tools (Claude, Gemini) to amplify our engineering capability - from code review and debugging to incident investigation and documentation. You don't need to be an expert, but you should be curious and willing to learn\n\nWhat You Get\nReal problems - trading systems where performance is measured in microseconds, not user clicks\n\nAn excellent team - senior engineers who care about craft, collaborate openly, and hold each other to high standards\n\nOwnership - small teams, clear accountability, direct impact on the platform and our clients\n\nCompetitive package - up to 30 days leave + bank holidays, private health insurance, pension, life insurance, dental/optical cashback, cycle to work, socials and offsites\n\nRemote-friendly - work from home with flexibility. We trust our people to deliver\n\nSustainable pace - we work hard, but we don't burn people out. Balance is how we stay sharp\n\nGrowth - career progression to senior roles, performance specialisation, or technical leadership. We invest in people who invest in us\n\nWe believe in transparency, honest feedback, and writing things down. We celebrate delivery, not activity. We frame AI as empowering people - removing toil, amplifying capability, enabling higher-value work.\nWe aim to build systems that don't depend on the heroics of individuals to maintain and support - systems and processes that are resilient, documented, and sustainable.\nOur Hiring Process\nWe keep our process focused and respectful of your time. Our process follows three stages.\nStage 1: Initial Conversation with Talent Acquisition\nFormat: Video call, ~30-45 minutes\nStage 2: Hiring Manager Conversation with the relevant team lead or hiring manager\nFormat: Video call, ~60 minutes\nStage 3: Technical Interview with two members of the relevant engineering team\nFormat: Video call, interactive session, ~60 minutes\nWhat to expect in each stage will be explained by Talent Acquisition if you're invited to interview. Throughout the process, we aim to keep momentum with no unnecessary delays between stages, and feedback typically comes within a few business days.\n*Please note that depending on availability, Stage 2 and 3 may swap around.\nHow to Apply\nPlease apply directly via this job posting - all applications, including those submitted via LinkedIn, are managed through our applicant tracking system, so you'll always land in the same place regardless of where you found this role.\nRight 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.\nEqual 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.\nReasonable Adjustments: If you need any adjustments or support during the application or interview process, please let us know - we're happy to accommodate.\nData Protection: By applying, you consent to Reactive Markets processing your personal data for recruitment purposes, in line with our privacy policy.\n#Hiring #SoftwareEngineering #Frontend #TypeScript #Rust #FinTech #TradingTechnology #RemoteWork #FullStack","description_format":"text","description_chars":7655,"description_truncated":false,"requirements":{"experience_years_min":null,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":["Health insurance","Life insurance"],"hiring_locations":[{"name":"United Kingdom","iso":"GB","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Financial Software & Embedded Finance","Stock Exchanges & Market Infrastructure"],"lifecycle":[{"event":"open","at":"2026-07-22T14:58:07Z"}],"visa":[],"liveness":{"score":29,"band":"fade","label":"Fading","p_open":1,"p_active":0.809,"p_room":0.36,"age_days":92,"expected_fill_days":61,"reasons":["conf:3","win:tail","crowd:"],"computed_at":"2026-10-23T05:54:15Z"},"pay":null,"html_url":"https://alion.io/job/reactive-markets-senior-frontend-engineer","json_url":"https://alion.io/job/reactive-markets-senior-frontend-engineer.json","meta":{"generated_at":"2026-10-24T04:11:45Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","about":"Alion is a live layer of people, companies and AI agents: who they are, whether they are real and active right now, what they do and how to work with them, readable by people and by agents and paid per call.","catalog":"https://alion.io/catalog.json","usage":{"tier":"crawler_verified","counted_by":"address","units_charged":1,"used_today":6579,"day_limit":null,"remaining_today":null,"minute_limit":300,"resets_at":"2026-10-25T00:00:00Z"}},"offers":[{"id":"company.slices","title":"One company in depth, by slice","status":"live","price":{"credits":0.02,"usd":0.002,"plus_per_slice":{"credits":0.05,"usd":0.005}},"unit":"per company, plus each slice with data","note":"the employer in depth","call":{"mcp_tool":"get_company","arguments":{"id":7325},"rest":"https://alion.io/mcp/rest/get_company?id=7325"},"human":"https://alion.io/catalog?offer=company.slices&for=job%2Freactive-markets-senior-frontend-engineer"},{"id":"market.stats","title":"A market slice: pay, demand and time to fill","status":"live","price":{"credits":1,"usd":0.1},"unit":"per slice","note":"pay, demand and time to fill for this role and place","call":{"mcp_tool":"market_stats"},"human":"https://alion.io/catalog?offer=market.stats&for=job%2Freactive-markets-senior-frontend-engineer"},{"id":"job.search","title":"Open jobs by role, technology, place, pay and visa","status":"live","price":{"credits":0.02,"usd":0.002},"unit":"per posting in a list","note":"similar open postings","call":{"mcp_tool":"search_jobs"},"human":"https://alion.io/catalog?offer=job.search&for=job%2Freactive-markets-senior-frontend-engineer"},{"id":"company.verify","title":"Is this company real and active right now","status":"pilot","price":null,"unit":"per company","request":{"url":"https://alion.io/catalog/request","method":"POST","body":"{\"offer\": \"company.verify\", \"for\": \"job/reactive-markets-senior-frontend-engineer\", \"note\": \"what you need it for\"}"},"human":"https://alion.io/catalog?offer=company.verify&for=job%2Freactive-markets-senior-frontend-engineer"}]}