Application Engineering Senior Developer - Dot NET Full Stack and Integrations | ErnstYoung Job

Job Description

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 loading.
• Familiarity with responsive design and enterprise UI standards.
• Experience troubleshooting and resolving production UI issues with minimal supervision.

Core Technology Stack

• Strong hands on experience with .NET / .NET Core, C#, and full stack application development.
• Extensive experience with RESTful API design and integration, including:
  • JSON payloads and schema validation
  • Authentication and authorization mechanisms
  • Structured error handling and resiliency patterns

Databases & Data Processing

• Advanced expertise in SQL Server, including:
  • Complex query design
  • Stored procedures and performance optimization
  • Controlled production data fixes
• Strong understanding of data reconciliation, validation, and high volume data handling.

ETL & Integration Platforms

• Hands on experience with Azure Data Factory (ADF) and/or SSIS.
• Knowledge of batch processing, scheduling, and dependency management.
• Experience designing scalable data pipelines for enterprise integrations.

Supervision Responsibilities:

• Direct reports
• Working relationships (daily) with EY ITSD and AMS Lead
• Working relationships (daily) with TCS AMS team
• Liaison to the Business for that Portfolio / App

Job Requirements:

Experience:

• 6+ years of experience in application engineering / full stack development, with significant exposure to enterprise integrations.
• Prior experience in lead or senior technical roles with ownership of production systems.
• Experience supporting large migrations, platform transitions, or enterprise cutovers is highly desirable.

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