Senior Backend .NET API Developer

Axos Business Center, Corp About This Job We are seeking a highly experienced Senior Backend .NET API Developer with strong expertise in financial services platforms to design, build, and optimize secure, scalable backend systems. The ideal candidate will have deep experience in .NET Core / ASP.NET APIs, microservices architecture, and high-volume transactional systems, with a strong understanding of banking/financial domain requirements such as security, compliance, and real-time processing. This role goes beyond development — the candidate is expected to actively participate in production incident (ITN) calls, take ownership of issue resolution, and drive root cause fixes to ensure system stability, uptime, and customer impact mitigation. Key Responsibilities Production Support & Incident Management (Critical Responsibility) Actively participate in ITN / production incident bridge calls and provide real-time technical troubleshootingTake end-to-end ownership of production issues impacting APIs and backend servicesPerform rapid debugging, issue isolation, and hotfix implementation during incidentsDrive root cause analysis (RCA) and implement permanent fixes to prevent recurrenceCollaborate with cross-functional teams (QA, DevOps, Infra) to restore service within SLA timelinesMonitor logs, metrics, and tracing tools to quickly identify production failuresEnsure post-incident documentation, learnings, and preventive measures are implemented Backend & API Development Design, develop, and maintain RESTful APIs and microservices using .NET Core / ASP.NET Core Build scalable backend services supporting high-volume transactions and financial workflowsImplement robust business logic for payments, accounts, transactions, and integrations Architecture & System Design Lead backend architecture design focusing on scalability, security, and performanceDefine API contracts, service interfaces, and data modelsDesign distributed systems, event-driven or microservices architectures Financial Domain & Compliance Ensure systems comply with financial regulations, security standards, and audit requirementsImplement secure transaction processing and data protection strategiesWork with domain teams on risk, reporting, settlement, or payment systems Database & Data Management Design and optimize relational and NoSQL databases (SQL Server, PostgreSQL, MongoDB)Ensure data integrity, consistency, and performance tuning Integration & Collaboration Integrate with external systems (e.g., payment gateways, banking APIs, third-party services)Collaborate with architects, product teams, QA, and DevOps teams Code Quality & Leadership Conduct code reviews, mentoring, and enforce best practicesDrive technical design discussions and solution architectureParticipate in Agile/Scrum processes Performance & Operations Optimize systems for low latency, high availability, and reliabilityTroubleshoot production issues and perform root-cause analysis Experience Required Qualifications 8–12+ years of experience in backend developmentStrong experience in financial services / banking / fintech domain (mandatory)Proven experience building enterprise-grade applications and APIs Technical Skills Strong proficiency in C#, .NET Core / .NET 8+ / ASP.NET CoreHands-on experience with REST APIs, Web APIs, and microservicesSolid knowledge of SQL Server and database designExperience with Entity Framework / ORM toolsUnderstanding of distributed systems, event-driven architecture Architecture & Cloud Experience with cloud platforms (Azure/AWS/GCP)Familiarity with Docker, Kubernetes, CI/CD pipelinesKnowledge of system design and scalability patterns Security & Compliance Strong understanding of:API security (OAuth2, JWT, OIDC)Data encryption and protectionFinancial compliance standards (PCI, SOX, etc.) Other Skills Strong analytical, problem-solving, and debugging skillsExcellent communication and stakeholder managementExperience mentoring and leading engineers Preferred Qualifications Experience with low-latency trading or real-time systems [builtin.com]Knowledge of payment systems (ACH, RTP, cards, SWIFT, etc.)Experience with event streaming (Kafka, RabbitMQ)Exposure to Domain-Driven Design (DDD) Education Bachelor’s or Master’s degree in Computer Science, Engineering, or related field What Success Looks Like Delivering secure, scalable APIs powering financial transactionsMaintaining high system uptime and performance under loadDriving architecture modernization and microservices adoptionEnabling compliant and reliable financial integrations Nice-to-Have (Based on Your Context – Optional Add-on) If you plan to tailor this for core banking / enterprise services (like your environment at Axos), you can explicitly add: Experience with identity platforms, payments systems, or core banking integrationsFamiliarity with event-driven enterprise platforms (Redis, RabbitMQ)Exposure to API gateways (Apigee). About Axos Born digital-first, Axos delivers financial tools and services that allow individuals, small businesses, and companies to access and manage their money how, when, and where they want. We’re a diverse team of dynamic, insightful, and independent innovators who are excited to provide technology-driven solutions that offer unbeatable value to our customers. Axos Financial is our holding company and is publicly traded on the New York Stock Exchange under the symbol "AX" (NYSE: AX). Learn More about working at Axos Business Center Pre-Employment Background Check, Medical, and Drug Test: All offers are contingent upon the candidate successfully passing a credit check, criminal background check, and pre-employment medical and drug screening. Equal Employment Opportunity: Axos is an Equal Opportunity employer. We are committed to providing equal employment opportunities to all employees and applicants without regard to race, religious creed, color, sex (including pregnancy, breast feeding and related medical conditions), gender, gender identity, gender expression, sexual orientation, national origin, ancestry, citizenship status, military and veteran status, marital status, age, protected medical condition, genetic information, physical disability, mental disability, or any other protected status in accordance with all applicable federal, state, and local laws. Job Functions and Work Environment: While performing the duties of this position, the employee is required to sit for extended periods of time. Manual dexterity and coordination are required while operating standard office equipment such as computer keyboard and mouse, calculator, telephone, copiers, etc. The work environment characteristics described here are representative of those an employee may encounter while performing the essential functions of this position. Reasonable accommodations may be made to enable individuals with disabilities to perform the essential functions of this position.