Senior Dotnet Developer

Zensar Technologies; Johannesburg; On-site; ZAR 900,000 - 1,600,000; Full time

Job summary

Zensar Technologies in Johannesburg is seeking a senior .NET Developer to design and deliver high‑throughput software in a distributed microservices environment. You will work with .NET 8+ and C# 12+, drive API design, and optimize performance across databases, caching, and messaging layers.

You’ll lead architectural discussions, mentor peers, and uphold SOLID principles, testing, and observability practices in a fast‑moving, collaborative team. This role is on-site in Johannesburg.

Qualifications

• Expert-level proficiency in .NET 8+ and C# 12+ (async/await, LINQ, performance tuning).
• Strong experience with Dapper and EF Core, including ORM trade-offs and performance tuning.
• Advanced SQL Server skills: query tuning, indexing, execution plans, statistics.
• Understanding of ACID, isolation levels, deadlocks, sharding, and partitioning (beneficial).
• Redis expertise in distributed caching and invalidation strategies (beneficial).
• Elasticsearch experience (indexing, search and aggregation performance).
• API design (REST / gRPC), backward compatibility, and versioning strategies.
• Strong ability to lead design discussions and influence architecture without formal authority.

Responsibilities

• Lead design discussions and influence architecture without formal authority.
• Build and maintain scalable systems within a distributed microservices architecture.
• Design and implement RESTful APIs with strong versioning and documentation standards.
• Develop event driven services using message queue technologies to support high volume, asynchronous workloads.
• Design and optimize databases, queries, and indexing for ultra high throughput environments.
• Implement advanced caching patterns (Redis, distributed caching) to reduce latency and boost performance.
• Drive code quality through rigorous reviews, adherence to SOLID principles, and best practice engineering standards.
• Mentor junior and mid-level developers and support their growth.
• Lead adoption of testing practices (unit, integration, contract, load testing).
• Identify opportunities for system refactoring, modernization, and performance improvement.

Skills

.NET 8+

C# 12+

Dapper

EF Core

SQL Server

API design REST/gRPC

Distributed microservices

Caching patterns (Redis)

OpenTelemetry

Testing automation

SOLID & design patterns

Code reviews

Mentoring

Education

Bachelor's degree in Computer Science or related field

Tools

Azure DevOps

OpenTelemetry

Redis

Elasticsearch

Kafka / message queues

Logging/Monitoring tooling

Job description

We’re a bunch of hardworking, fun-loving, people-oriented technology enthusiasts. We love what we do, and we’re passionate about helping our clients thrive in an increasingly complex digital world. Zensar is an organization focused on building relationships with our clients and with each other—and happiness is at the core of everything we do. In fact, we’re so into happiness that we’ve created a Global Happiness Council, and we send out a Happiness Survey to our employees each year. We’ve learned that employee happiness requires more than a competitive paycheck, and our employee value proposition—grow, own, achieve, learn (GOAL)—lays out the core opportunities we seek to foster for every employee. Teamwork and collaboration are critical to Zensar’s mission and success, and our teams work on a diverse and challenging mix of technologies across a broad industry spectrum. These industries include banking and financial services, high-tech and manufacturing, healthcare, insurance, retail, and consumer services. Our employees enjoy flexible work arrangements and a competitive benefits package, including medical, dental, vision, 401(k), among other benefits. If you are looking for a place to have an immediate impact, to grow and contribute, where we work hard, play hard, and support each other, consider joining team Zensar!

Zensar is looking for .NET Developer in Johannesburg

Role Overview

• Expert‑level proficiency in .NET 8+ and C# 12+ (async/await, LINQ, performance tuning, reflection).
• Strong experience with Dapper / EF Core, including ORM trade‑offs and performance tuning.
• Advanced SQL Server skills: query tuning, indexing, execution plans, statistics.
• Deep understanding of ACID, isolation levels, deadlocks, sharding, and partitioning. (Beneficial)
• Redis expertise in distributed caching and invalidation strategies. (Beneficial)
• Elasticsearch experience (indexing, search and aggregation performance optimizations). (Beneficial)
• API design (REST / gRPC), backward compatibility, and versioning strategies.
• Strong ability to lead design discussions and influence architecture without formal authority.

DevOps, CI/CD & Observability:

• Advanced Azure DevOps pipeline design and release management.
• Understanding of modern deployment strategies (blue‑green, canary, etc).
• Experience with logging, tracing, and performance monitoring (OpenTelemetry). (Beneficial)

Software Quality & Craftsmanship:

• Deep experience with testing automation across all testing layers.
• Strong understanding of SOLID principles, design patterns, and refactoring practices.
• Performance profiling, optimization, and debugging complex scenarios.

Production Ownership:

• Experience leading incident response, post‑mortems, and operational improvement efforts.
• Ability to maintain composure and lead through high‑severity production challenges.

Soft Skills & Professional Strengths:

• Excellent technical communication and ability to explain complex concepts to diverse audiences.
• Strong ownership mindset — you take responsibility for outcomes, not just tasks.
• Adaptability in a fast‑moving environment with changing priorities.
• Collaborative and team‑oriented, with strong cross‑functional communication.
• High attention to detail, especially in regulated environments.
• Proactive, solution‑driven, and resilient under pressure.

Core Development & Architecture:

• Build and enhance scalable systems within a distributed microservices architecture.
• Design and implement RESTful APIs with strong versioning and documentation standards.
• Develop event driven services using message queue technologies to support high volume, asynchronous workloads.
• Design and optimize databases, queries, and indexing for ultra high throughput environments.
• Implement advanced caching patterns (Redis, distributed caching) to reduce latency and boost performance.

Code Quality & Technical Leadership:

• Drive code quality through rigorous reviews, adherence to SOLID principles, and best practice engineering standards.
• Mentor junior and mid-level developers and support their growth.
• Lead adoption of testing practices (unit, integration, contract, load testing).
• Identify opportunities for system refactoring, modernization, and performance improvement.

Zensar believes that diversity of backgrounds, thought, experience, and expertise fosters the robust exchange of ideas that enables the highest quality collaboration and work product. Zensar is an equal opportunity employer. All employment decisions shall be made without regard to age, race, creed, color, religion, sex, national origin, ancestry, disability status, veteran status, sexual orientation, gender identity or expression, genetic information, marital status, citizenship status or any other basis as protected by federal, state, or local law. Zensar is committed to providing veteran employment opportunities to our service men and women. Zensar is committed to providing equal employment opportunities for people with disabilities or religious observances, including reasonable accommodation when needed.