Senior .NET C# Developer

We are looking for a Senior .NET C# Developer to join a growing European Platform & APIs team. This is a strategic senior-level role with direct impact on architecture and platform evolution. You will be working on transitioning a hybrid monolith/microservices system toward a fully event-driven, service-oriented architecture.

Project – the platform that delivers mission-critical news generation and structured data extraction services for leading global financial information providers. It processes millions of web scrapes daily and transforms unstructured content into normalized, real-time intelligence used by financial markets worldwide.
This is a distributed, high-load environment with strict latency requirements and complex microservice contracts.

Requirements

• 5+ years of professional experience with .NET / C#
• Strong expertise in microservices architecture
• Hands-on experience with event-driven systems
• Production experience with AWS (SQS, S3, EC2 or similar)
• Experience with SQL and NoSQL databases (MongoDB & Elasticsearch preferred)
• Solid knowledge of async/await, threading, and resource management
• Experience working with distributed systems: Message queues (SQS, RabbitMQ, Kafka, etc.), Retry strategies, Idempotency
• Logging & debugging in distributed environments
• Proven experience modernizing legacy systems
• Strong analytical and architectural thinking
• Performance-focused mindset
• QA-driven thinking (edge cases, failure modes, resilience)
• Advanced English and better

Nice to have:

• Experience with high-volume web scraping or document processing systems
• Experience in financial services or real-time data processing environments
• Knowledge of Elasticsearch internals
• Python experience for data workflows
• Docker / Kubernetes experience

What You’ll Do

Your primary focus will be the web-retrieval domain, including a sophisticated matching engine that determines which scraped content should be processed.

• Migrating and refactoring our core platform components to modern architectures (initial focus, ~100% of time)
• Modernizing infrastructure by migrating services to the latest versions of MongoDB, Elasticsearch, and .NET (currently 4.7.2, moving to latest)
• Building greenfield APIs that expose platform capabilities to our next-generation web applications (growing to ~80% of time as migration stabilizes)
• Supporting web app teams through collaborative API design, documentation, and troubleshooting
• Improving platform reliability by increasing test coverage, velocity, and effectiveness.

This role offers significant autonomy and architectural influence, with strong support from our Director of Engineering. Over time, there are opportunities to take on mentoring responsibilities if that aligns with your interests.

What We Offer

• Vacation (up to 20 working days)
• Sick leaves (10 working days)
• National Holidays as time off (11 days)
• Medical Insurance after 3 months probation period (can be used in Ukraine)
• Online English courses
• Accountant assistance and legal support
• Flexible working schedule, remote, office-based or hybrid format
• Fully-equipped perfect office space located in the city center (ready for work in blackouts)
• Direct cooperation with the customer
• Dynamic environment with low level of bureaucracy and great team spirit
• Communication with Top/Senior level specialists to strengthen your hard skills
• Online/offline teambuildings
• Volunteering culture development and support