Application Engineering Senior Developer - Dot NET Full Stack and Integrations

At EY, you’ll have the chance to build a career as unique as you are, with the global scale, support, inclusive culture and technology to become the best version of you. And we’re counting on your unique voice and perspective to help EY become even better, too. Join us and build an exceptional experience for yourself, and a better working world for all.

Application Engineering Senior Developer – .NET Full Stack & Integrations    Application Engineer Lead   Job Summary: The Application Engineering Lead is responsible for designing, building, and owning complex full stack applications and enterprise integrations. This role requires deep technical expertise across .NET, API integrations, databases, and data pipelines, along with strong ownership of production systems, migration activities, and critical cutovers. The role operates with minimal supervision and serves as a key technical decision maker and escalation point.   Roles & Responsibilities Application Development & Integrations

Lead the design and implementation of API integrations using REST, JSON , and industry standard authentication mechanisms (OAuth2, JWT, API keys, etc.). Lead the design and Implementation of Front end applications using Angular/HTML/Typescript Build and maintain robust, secure, and scalable integrations with structured error handling, logging, and retry mechanisms. Design and implement reverse and batch integrations across internal and external systems. Act as the technical authority for complex integration patterns, data flows, and migration solutions.

Database & Data Engineering

Design and develop SQL Server solutions , including complex queries, stored procedures, performance tuning, and indexing strategies. Perform production data fixes with strong governance, validation, and audit controls. Implement and manage ETL and data pipelines using Azure Data Factory (ADF) and/or SSIS . Handle large scale, high volume data processing , ensuring data accuracy, reconciliation, and integrity across systems.

Production Ownership & Reliability

Own end to end accountability for critical production systems and integrations. Lead production issue triage, root cause analysis, and remediation, maintaining composure and sound judgment during high severity incidents. Serve as a trusted escalation point during production issues, migration waves, and release cutovers. Ensure system stability, observability, and operational readiness across environments.

Leadership & Stakeholder Management

Operate independently with minimal guidance , making informed technical and delivery decisions. Act as a subject matter expert (SME) for integration and migration initiatives. Collaborate effectively with business stakeholders, architects, and delivery teams to translate requirements into technical solutions. Coordinate across multiple teams during migrations and production cutovers, ensuring aligned execution and clear communication. Mentor and guide engineers on integration patterns, coding standards, and operational best practices.

Knowledge and Skills Requirements: Frontend & UI Engineering (Angular)

Strong hands on experience with Angular (version 20+) for enterprise grade web applications. Expertise in TypeScript, HTML5, CSS3, and modern JavaScript (ES6+). Experience designing and implementing component based architectures, reusable modules, and shared UI libraries. Strong understanding of Angular lifecycle hooks, dependency injection, routing, and state management. Experience with RxJS and reactive programming, including observables, subjects, and subscription management. Ability to consume and integrate REST APIs into Angular applications with proper error handling and retry logic. Experience implementing authentication and authorization mechanisms on the UI (token handling, role based access, guards). Proficiency in frontend performance optimization, change detection strategies, and lazy