Vitae Recruitment is seeking a highly skilled Senior .NET Engineer to join a reputable private company based in Limassol, Cyprus. Our client is looking for a senior backend engineer to own the architecture, delivery, and quality of the server-side platform powering their trading systems. The platform is built in .NET with C# as
event-driven microservices and operated as a production-grade backend engineering product. A successful candidate will work confidently across the entire stack - from domain modelling and application services, through the data and messaging layers, to the integration boundaries with trading servers and external systems where throughput or correctness demands it. This is a senior individual-contributor role carrying architectural authority over the backend platform. The platform is data-dense and latency-sensitive, ingesting high-frequency market data, processing live order and position state, and fanning out updates to downstream consumers. Sustained high-throughput ingestion, single-digit-millisecond hot paths, and bounded, predictable resource usage under load are baseline operating requirements rather than optimisation targets.
BACKEND DEVELOPMENT:
- Design and deliver core backend services, releasing well-versioned, horizontally scalable microservices with clear ownership and operational maturity.
- Build domain logic, application services, and data orchestration in C# under strict nullable, analyzers, and typed contracts at every external boundary.
- Maintain stateless, idempotent service behaviour with predictable data flow and explicit consistency guarantees.
Integration & Interop
- Author and maintain integrations with trading servers and external systems - including MT5/MT4 Manager API surfaces and native interop via P/Invoke where required - with typed contracts and deterministic lifecycle management.
- Reason across synchronous and asynchronous, in-process and out-of-process boundaries, including legacy services not yet migrated, and lead the incremental, measurable migration of legacy code.
- Apply disciplined judgment regarding which boundary - in-process, RPC, or message - a given concern belongs to.
PERFORMANCE & REAL-TIME DATA:
Throughput & Performance
- Master asynchronous programming across the platform: async/await, the task scheduler, cancellation, IAsyncEnumerable, channels, and pipelines, minimising allocations using Span<T> / Memory<T> and pooling.
- Apply parallel execution correctly - the TPL, Parallel / PLINQ, and lock-free, thread-safe data structures (concurrent and immutable collections) - selecting efficient data structures for the access and contention pattern at hand.
- Profile hot paths with BenchmarkDotNet, dotnet-trace, and dotnet-counters; eliminate lock contention, and tune GC behaviour under sustained load.
- Sustain high-throughput ingestion with backpressure, bounded concurrency, and graceful degradation.
Connectivity & Protocols
- Own the real-time data layer: resilient gRPC and WebSocket/SignalR connectivity for quotes, order updates, and market-data fan-out.
- Implement reconnection and resequencing, backpressure, message idempotency, and deterministic state reconciliation under adverse and lossy conditions.
- Apply advanced command of the protocols underpinning a real-time financial application:
- ○ gRPC - unary and bidirectional streaming, Protobuf schema evolution, channel/deadline management, interceptors.
- ○ WebSocket / SignalR - framing, liveness detection, resync strategy, ordering/idempotency, scale-out backplanes
- ○ HTTP/1.1 & HTTP/2 - connection pooling, multiplexing, keep-alive tuning, and performance characteristics under load.
- ○ TLS - certificate validation, pinning and rotation strategy, mTLS for service-to-service trust.
- ○ REST / JSON / OpenAPI - contract design, schema validation, and versioning.
- ○ OAuth 2.0 / OIDC - client-credentials and refresh/rotation flows, token validation, and secret storage.
- ○ Messaging - delivery semantics, ordering, partitioning, dead-lettering, and exactly-once/at-least-once trade-offs.
ARCHITECTURE & QUALITY:
Architecture & Design
- Apply and uphold Clean Architecture, the SOLID principles, CQRS (MediatR), and Domain-Driven Design (DDD): a strict dependency rule, well-defined aggregates and bounded contexts, and domain models insulated from framework and transport detail.
- Design with rigorous object-oriented modelling - sound abstractions, composition over inheritance, and well-defined interfaces - and decompose the platform into cohesive, independently deployable microservices with explicit contracts and failure boundaries.
- Maintain clear separation between domain, application, and infrastructure concerns across an event-driven, domain-decomposed codebase.
Testing & Standards
- Practise Test-Driven Development (TDD), ensuring meaningful unit, integration (Testcontainers), end-to-end, and contract coverage, with quality gates enforced in CI.
- Lead code reviews and enforce engineering standards across typed boundaries, testing strategy, performance budgets, and security.
RELEASE & OPERATIONS:
Release Engineering
- Own release engineering end to end: containerised builds, deployment to AWS ECS Fargate, and blue/green and canary rollouts.
- Manage infrastructure as code (Terraform) and database schema evolution (EF Core migrations) with safe, reversible change.
- Implement configuration, secrets management, and environment promotion across staging and production.
Observability & Reliability
- Define and enforce backend observability: structured logging, distributed tracing, and metrics correlated across services (OpenTelemetry).
- Define, monitor, and uphold service SLAs/SLOs (availability, p99 latency, error budgets) and engineering delivery performance via DORA metrics (deployment frequency, lead time, change failure rate, MTTR).
PRODUCT & DELIVERY:
- Operate within an Agile delivery model - iterative planning, estimation, and continuous improvement of team practices.
- Maintain a product-oriented mindset, framing technical work in terms of user and business outcomes, and contribute to OKRs and product KPIs for the backend platform.
- Provide technical leadership and mentorship to mid-level engineers, and represent backend architecture in cross-functional decisions.
- Collaborate with mobile, frontend, and infrastructure on API/event contracts and shared platform standards.
TECHNICAL SKILLS:
Category Technologies & Tools
Core Framework .NET 8 / C#, ASP.NET Core, Minimal APIs / FastEndpoints
Architecture Clean Architecture, SOLID, OOP, CQRS (MediatR), Domain-Driven Design, microservices
Data Access EF Core, Dapper, MySQL / Amazon RDS, ClickHouse, Redis
Real-Time &
Protocols gRPC / Protobuf, SignalR / WebSocket, HTTP/2, REST / OpenAPI, OAuth 2.0 / OIDC, TLS
Messaging Kafka, RabbitMQ, AWS SNS / SQS, EventBridge
Concurrency &
Performance async/await, TPL / PLINQ, concurrent & immutable collections, Span<T>, BenchmarkDotNet, dotnet-trace / counters, GC tuning
Testing TDD, xUnit / NUnit, Testcontainers, contract testing, integration testing
CI/CD & Release Docker, GitHub Actions, Terraform, ECS Fargate, blue/green & canary
Observability OpenTelemetry, Grafana, Datadog, Prometheus, CloudWatch
Cloud AWS (ECS Fargate, RDS, S3, IAM)
Delivery Metrics SLAs / SLOs, DORA, KPIs / OKRs
Domain MT5 / MT4 Manager API, market data, order management
QUALIFICATIONS:
Required
- 4+ years of production backend development, with demonstrated depth in .NET and C#.
- 3+ years building and operating event-driven microservices in production at scale.
- Expert-level C# and object-oriented design, with a thorough command of asynchronous and parallel programming, efficient and thread-safe data structures, the CLR memory and GC model, and performance profiling.
- Proven experience operating real-time streaming data within a deployed backend at scale.
- Comprehensive understanding of distributed systems: consistency, idempotency, partial failure, backpressure, and observability.
- Demonstrated, hands-on application of SOLID, Clean Architecture, CQRS, and DDD in production software.
- Deep microservices expertise - service decomposition, independent deployability, inter-service contracts, and resilience patterns.
- Strong relational and analytical data skills (MySQL; ClickHouse or a comparable columnar/time-series store an advantage).
- Full ownership of CI/CD and containerised deployment to a cloud platform.
- Proven delivery within Agile teams with a product-oriented mindset, and fluency in outcome and delivery measurement.
Preferred
- Experience within fintech, trading, or a comparable regulated, latency-critical domain.
- Trading-platform integration experience (MT5 / MT4 Manager API, FIX, or equivalent).
- High-throughput time-series / market-data systems and columnar analytics (ClickHouse).
- AWS depth (ECS Fargate, RDS, EventBridge) and infrastructure-as-code with Terraform.
- Familiarity with observability platforms (Grafana, Datadog, Prometheus, CloudWatch).
- Degree in Computer Science, Software Engineering, or a related field.
BENEFITS:
- Competitive senior-level salary with annual performance review.
- Certification and professional development budget.
- Hybrid working arrangements and a collaborative team culture.
This is a fantastic opportunity for a dedicated IT professional looking to work in a vibrant and innovative environment. The role offers a competitive remuneration package that reflects your qualifications and experience. Joining this company provides the chance to be part of a growing organisation where your expertise will have a significant impact. The company fosters a collaborative culture and offers excellent career development prospects for the right candidate.