Senior Software Development Engineer

SUMMARY: Ampersand is redefining how businesses and public entities manage deposits at scale—combining fintech innovation, treasury intelligence, and secure infrastructure into a unified platform that turns cash into a strategic asset.  Our platform empowers B2B clients across both public and private sectors to handle complex financial workflows securely, efficiently, and in real time.Our technology is the core enabler of our service model—not just supporting operations but defining our market advantage. With our initial platform version launching soon, we’re entering a massive and fast-growing market with a clear opportunity to scale rapidly, capture market share, and expand through API-driven services and potential white-label offerings.We’re hiring a Senior Software Development Engineer to design, build, and evolve the next generation of our platform and API ecosystem. This role is deeply hands-on—writing code daily, designing scalable systems, and helping shape the foundation for enterprise growth and extensibility.This role is perfect for emerging Architects as you’ll work alongside our CTO to evolve our back-end architecture and API layer to support rapid growth, extensibility, and enterprise integrations. Your work will directly impact our ability to scale, support new customer types, and unlock future go-to-market models like platform licensing, API integrations, and white-labeled solutions. ESSENTIAL DUTIES & RESPONSIBILITIES: The following is a list of essential functions which may be subject to change at any time and without advance notice. Management may assign new duties, reassign existing duties, or eliminate a function.Platform Architecture & EvolutionProgress the architectural roadmap as we expand from an internal platform to a scalable, productized solution.Design for multi-tenancy, modular deployments, and white-label capabilities.Collaborate with the CTO to evolve system architecture to build with future growth in mind: extensibility, observability, and onboarding velocity.Participate in architecture reviews and contribute to technical standards.API Design & StrategyLead the design and implementation of robust, secure, and reusable RESTful APIs to support integrations with:Banking systemsRetail POS systemsCash logistics providersPublic-sector financial systemsOwn API governance, lifecycle management, and documentation for future partner-facing exposure.Implement and test multi-tenant and modular capabilities in code.Rules-Based Engine & Financial LogicExtend the architecture of a configurable calculation engine to handle:Reconciliation workflowsFee structuresExceptions and compliance logicSLA enforcementEnable non-engineering teams to manage business logic via config, UI, or DSL-based tools.Scalability, Security & ComplianceEnsure the platform is scalable, highly available, and secure—built to handle regulated financial data with full traceability and audit controls.Implement data isolation, access control, and logging to support multi-client deployments and public-sector compliance requirements (SOC2, PCI-DSS, etc.).Technical Leadership & Cross-Team InfluenceAct as a thought partner to business leaders as we explore new delivery models.Provide leadership and mentor engineers on architectural best practices and platform thinking.Translate customer requirements into scalable architectural patterns.Support code reviews and help improve platform engineering quality and velocity. QUALIFICATIONS, EDUCATION & EXPERIENCE:6 years of experience in back-end engineering, with 2 in an architectural or platform leadership role.Proven experience progressing multi-tenant platforms, complex APIs, or B2B financial systems.Practical, hands-on experience with C# programming language to develop software applications.Deep knowledge of:Scalable API design (REST API gateways, versioning)Modular architecture, microservices, and event-driven systemsSecure system design: authentication (OAuth2, JWT), encryption, RBACConfigurable/rule-based business logic systemsExperience working in a regulated or compliance-driven environment.Bachelor’s degree in Computer Science, Software Engineering, or a related field (required); Master’s degree or MBA a plus.Relevant certifications are a strong plus:Azure Solutions ArchitectTOGAF or equivalent enterprise architecture frameworkSecurity certifications (e.g., CISSP, CISM) for compliance-heavy environmentsAPI and microservicesHelpful if you have:Background in fintech, cash logistics, treasury, banking, or public-sector financial systems.Experience launching or scaling a platform from internal use to an external product.Familiarity with domain-driven design (DDD), event sourcing, or policy-as-code tools.Past involvement in productizing APIs or white-label software. SKILLS & COMPETENCIES: System DesignDeep experience with distributed, scalable, modular systems, including microservices and service orchestrationAPI ExpertiseExpertise in designing, documenting, and securing external and internal APIs (REST) utilizing C#.Rules Engine DesignExperience with configurable or rule-based engines for dynamic business logicSecurity-First MindsetStrong grounding in secure architecture, compliance standards, and access controlMulti-Tenancy & White labelingUnderstanding of tenant isolation, brand customization, and configurable deploymentsCloud-Native InfrastructureExperience with cloud architecture patterns (preferably Azure)Strategic ThinkingAbility to balance technical decisions with long-term product strategy and market expansionCollaboration & InfluenceStrong communicator who can work cross-functionally and guide teams on complex architecture decisionsExecution Under UncertaintyAbility to design with flexibility in mind, anticipating future growth and pivotsEntity Framework/MS SQL ServerExpertise in the use of Entity Framework and MS SQL Server, including data lake designCompany DescriptionAmpersand is redefining how businesses and public entities manage deposits at scale—combining fintech innovation, treasury intelligence, and secure infrastructure into a unified platform that turns cash into a strategic asset. Our platform empowers B2B clients across both public and private sectors to handle complex financial workflows securely, efficiently, and in real time.Our technology is the core enabler of our service model—not just supporting operations but defining our market advantage. With our initial platform version launching soon, we’re entering a massive and fast-growing market with a clear opportunity to scale rapidly, capture market share, and expand through API-driven services and potential white-label offerings.