Senior C# & SQL Performance Engineer — Batch & Big Data

Phi Partners; Paris; On-site; EUR 70,000 - 110,000; Full time

Job summary

Phi Partners seeks a senior C# / SQL developer to own batch processing behind a mission-critical financial application. You will analyse algorithms, reengineer queries and optimise large-scale data workflows across C# and Oracle environments.

You will profile components, manage Control-M scheduled jobs and contribute to Hadoop-based data processing while ensuring seamless frontend-backend integration with Angular and NestJS. Strong problem-solving and capital markets awareness are valued.

Qualifications

• Proven C#/.NET and Oracle SQL engineering expertise.
• Strong performance engineering, batch optimisation and profiling.
• Experience with scheduled workloads and Control-M orchestration.
• Big Data processing with Hadoop, Spark, Python, Hive and Kafka.
• Web apps with Angular/NestJS and backend service integration.
• Autonomous, proactive problem-solving on complex challenges.
• Desirable knowledge of capital markets and fintech environments.

Responsibilities

• Analyzing payoff and observability determination algorithms, reviewing processing logic, calculation flows and data dependencies to identify functional and technical inefficiencies.
• Reengineering core algorithms and SQL queries, simplifying processing logic and improving data retrieval and transformation across the application.
• Profiling C# application components and Oracle database operations, diagnosing execution bottlenecks and optimising resource-intensive processes across high-volume datasets.
• Managing batch processing workflows through Control-M, supporting the C#/Oracle batch application and ensuring reliable scheduling, execution and integration with downstream processes.
• Working with Big Data processing on Hadoop, analysing large-scale data workflows and contributing to improvements across distributed batch-processing components.
• Supporting the Angular/NestJS web interface, investigating application behaviour and ensuring effective integration between the frontend, backend services and underlying processing components.
• Identifying architectural and technical improvements, independently evaluating existing implementations, proposing solutions and driving changes from development through production delivery.
• Documenting technical implementations and validating application changes, performing functional and regression testing to safeguard business logic, data integrity and system reliability.

Skills

C#/.NET

Oracle SQL

Batch processing

Big Data

Angular/NestJS

Performance optimization

Autonomous problem-solving

Capital markets knowledge

Job description

Phi Partners seeks a senior C# / SQL developer to own batch processing behind a mission-critical financial application. You will analyse algorithms, reengineer queries and optimise large-scale data workflows across C# and Oracle environments.

You will profile components, manage Control-M scheduled jobs and contribute to Hadoop-based data processing while ensuring seamless frontend-backend integration with Angular and NestJS. Strong problem-solving and capital markets awareness are valued.