Principal Software Engineer

Principal Software Engineer – C#/.NET Core & AWS | AI-Enabled Platforms | $200,000 - $240,000 + bonus & RSUs | Hybrid (3-days in office)

I’m recruiting for a global leader in professional information and enterprise software, and they need a hands-on Principal Engineer to help modernise a major U.S. tax compliance platform.

The opportunity

This is a true Principal IC role: you’ll own architecture and technical direction for large-scale production systems, shape decisions across multiple engineering teams, and stay close to the code. No ivory tower.

What you’ll do

• Own architecture and system design for complex, high-scale platforms, balancing scalability, reliability, performance and security
• Build production software in C#/.NET Core on AWS, staying hands-on in design, delivery and problem-solving
• Lead the move from legacy applications to cloud-native architectures: microservices, APIs, distributed systems and containerised workloads
• Set technical direction and influence engineering decisions across teams
• Mentor through design reviews, code guidance and best practice
• Identify and deliver practical uses of AI/ML and Generative AI in production products
• Help shape the long-term technical roadmap and communicate trade-offs and risks

What you’ll bring

• 10+ years in software engineering, with proven Principal-level (or equivalent senior IC) scope
• Strong, recent, hands-on C#/.NET Core experience
• Deep production AWS experience across services such as EC2, S3, ELB, Auto Scaling, RDS, Lambda, SQS and container services
• A track record of architecting and building large-scale distributed systems, microservices and highly available applications
• Experience modernising complex legacy systems into resilient, cloud-native solutions
• Strong grounding in architecture, OO design, algorithms, design patterns, API design and relational databases
• Excellent communication, able to influence across Product, Engineering, Security, QA, Data and Ops
• Degree in Computer Science or a related field, or equivalent experience