Senior Application Support Engineer

Come join oneZero Financial Systems! An exciting, fast-growing company with Headquarters in Somerville MA, oneZero empowers banks, brokerages, and hedge funds with cutting-edge trade routing and execution technology. Our platform, deployed with 200+ entities globally, features a low-latency trading environment, integrations to the world’s leading execution venues, and reliable IT infrastructure and technical support-all designed to be customized and scaled to serve any business model and any size of market participant. We take pride in our great work atmosphere and highly motivated team of engineers. We are currently looking for a motivated and talented Senior Application Support Engineer to join ourCyprus office.

Over the last few years, oneZero has seen a surge of interest from our client base in the trading of digital assets like bitcoin and other cryptocurrencies. Our platform is primed and ready to support this emerging asset class, allowing our clients to actively participate in the digital asset space 24 hours a day, 7 days a week.

We’re excited to expand and evolve our support model to accommodate the continuous trading hours of these digital assets. This change will also put us in the perfect position to handle the traditional OTC FX markets’ transition to extended off-hours trading.

Come and join the oneZero team to collaborate on this brand-new industry dynamic!

oneZero is proud to have been named one of Business Intelligence Group's Best Places to Work for four consecutive years: https://www.onezero.com/awards/onezero-earns-recognition-as-a-2025-best-place-to-work/

oneZero earns 2025 Great Place To Work Australia Certification: https://www.onezero.com/awards/onezero-earns-2025-great-place-to-work-australia-certification/

The Boston Globe names oneZero a Top Place to Work in 2022, 2023, and 2024: https://www.onezero.com/homepage/the-boston-globe-names-onezero-a-top-place-to-work-for-third-year-

Job Purpose: The Senior Application Support Engineer ensures the stability, performance, and security of oneZero production trading platforms through advanced incident response, independent technical decision-making, and continuous operational improvement. This position supports customer-facing operations at a senior level by leading client-impacting incident response, guiding technical communications, and ensuring timely, high-quality outcomes within service commitments. This role leads complex deployments and client implementations across enterprise trading platforms and related components, owning production readiness, risk assessment, and successful transitions to steady-state support.

Key Responsibilities

• Architect and execute complex deployments and upgrades/migrations: define validation strategy, monitor key indicators, and determine rollout progression and release authorization decisions.

• Lead end-to-end client implementations by assessing readiness criteria, identifying dependencies, designing deployment sequencing, and validating oneZero product configurations and integrations.
• Assess client connectivity and integration requirements, and recommend configuration approaches and integration processes that balance technical constraints with business objectives.
• Drive cross-functional collaboration with key stakeholders to assess feasibility, define technical requirements, and manage risk for deployments and implementations.
• Improve operational maturity by evolving runbooks, procedures, monitoring/alerting frameworks, and change management practices.
• Continuously self-learn and upskill across products, systems, and investigation processes to maintain strong operational capability as platforms and client requirements evolve.
• Identify opportunities to reduce manual effort and operational burden through improvements to processes, tooling, and monitoring. Coordinate delivery with appropriate stakeholders while maintaining required controls.
• Apply security best practices through disciplined access control and secure handling of sensitive information. Operate within change and incident governance processes using risk-based judgment.
• Provide client support within SLA commitments across multiple support channels, managing concurrent communications during high-pressure events.
• Mentor junior engineers through technical guidance, analytical coaching, and knowledge transfer.
• Participate in on-call and occasional weekend coverage on a rotating schedule.
• Lead investigations into trade execution and market data issues using logs, metrics, traces, and FIX/API message flows. Determine whether issues can be resolved operationally or require engineering escalation.
• Lead major incident management for client-impacting production events. Assess severity and business impact, coordinate restoration activities, and provide clear stakeholder communication.
• Lead post-incident analysis: document decisions and outcomes, identify contributing factors, and drive preventive improvements.

Required Skills

• 5+ years supporting production systems in the financial markets domain, with in-depth knowledge of trade support, financial technology operations, project delivery, and critical incident management.
• Strong operating system proficiency and networking expertise, including effective diagnostics and troubleshooting, with foundational TCP/IP knowledge.
• Experience with production systems and application monitoring, including alerting practices and the ability to correlate metrics, logs, and traces to isolate service-impacting issues.
• Proven ability to independently analyze complex, multi-system issues and select sound remediation options under time pressure.
• Demonstrated experience improving operational processes, tooling, and documentation to reduce manual effort and increase consistency.
• Direct experience leading technical client implementations: readiness checks, configuration validation, testing, and production deployment.
• Familiarity with integration processes across vendor trading and financial technology platforms in production environments, including connectivity, configuration, and data flow validation.
• Clear written and verbal communication skills, with the ability to explain technical issues to both technical and non-technical stakeholders.
• Demonstrated ability to develop and improve operational documentation, runbooks, and procedures.
• Experience mentoring, training, or coaching junior engineers.

Preferred Skills

• Experience supporting financial technology platforms within electronic trading environments, with a strong understanding of production trade support responsibilities and electronic trading workflows.
• Deep understanding of FIX protocol message lifecycles and session behavior, with proven experience investigating production trading and quoting issues through end-to-end message analysis.
• Hands-on MetaTrader 4/5 application experience, including server installation, administration, deployment, and bringing environments to a production-ready operational state.
• Working knowledge of SQL, including experience with PGSQL and MySQL for investigation, validation, and operational reporting.
• Basic scripting and automation skills (Python, Bash, PowerShell, or similar) with examples of tooling you've built.
• Familiarity with enterprise AI capabilities and responsible usage practices to improve operational analysis, documentation quality, and productivity while adhering to data handling, security, and governance requirements.
• Experience supporting containerized application runtimes in production, including deployment coordination, service health troubleshooting, and resource and network diagnostics.
• Experience supporting streaming and message-oriented systems in production, including monitoring throughput and latency, diagnosing delivery and processing issues, and coordinating remediation.