Danai Zerai

Danai Zerai

Backend Engineer · Solution Architect

Manchester, UK
Available for contract & freelance work

About Me

I'm a backend engineer based in Manchester, UK with a First Class BSc in Computer Science from the University of Liverpool. I specialise in building high-performance backend systems — from greenfield APIs to complex distributed architectures — primarily in Go and C#/.NET.

Most recently, I worked at WM Reply, a Microsoft Partner consultancy, where I built serverless Azure solutions, AI-driven automation tools, and enterprise data-processing pipelines for clients including ASOS. Before that, I owned the full backend of a product at 21D — scaling it from zero to 10,000+ users in weeks, migrating from Go on AWS to C#/.NET on Azure with zero downtime, and maintaining 99.9% uptime.

I'm available for backend contracts and freelance projects. If you need a backend that's fast, reliable, and built to scale — let's talk.

Work Experience

Software Developer

WM ReplySept 2024 – July 2025Manchester, UK
  • Built serverless Azure Functions in C#/.NET processing large-scale CSV workloads, saving clients ~£5k/quarter
  • Delivered AI-driven automation tools reducing manual workload by 35% and improving query response speed 5x
  • Developed full-stack internal tool for 200 users, improving satisfaction by 90%
  • Worked on engagements converting trials to contracts — including ASOS

Backend Engineer

21D2024Remote
  • Owned end-to-end backend development scaling 0 → 10,000+ users in weeks
  • Maintained 99.9% uptime handling ~35k API requests/day
  • Led zero-downtime migration from Go on AWS to C#/.NET on Azure
  • Reduced p95 latency from 1,200ms to 280ms via async processing and caching

Full-Stack Developer

Self-EmployedJan 2024 – Aug 2024Manchester, UK
  • Built production systems for multiple clients across AWS, Azure, and on-prem
  • Developed Go/Next.js booking app saving clients ~5 admin hrs/week
  • Delivered JBaker.uk portfolio — 3x more employer attention, interviews at 2 major firms
  • Built fitness tracker serving 500+ users

Tech Stack

primary

GoC#TypeScriptJavaScript

cloud

AzureAWSAzure FunctionsAzure Service Bus

frameworks

.NETASP.NET CoreNext.jsNode.jsReact

databases

PostgreSQLSQL ServerRedis

tools

DockerGitGitHub ActionsAzure DevOpsApplication Insights

Education

BSc Computer Science (First Class)

University of Liverpool

First Class Honours
AlgorithmsDatabasesCloud ComputingSoftware EngineeringAI & Machine Vision

Certifications

  • Backend Web Development with .NET
  • Web Security: OAuth and OpenID Connect
  • Java Spring Framework in Depth
  • Designing RESTful APIs
  • Microsoft Certified: PL-900 Power Platform Fundamentals

Let's Work Together

I'm currently available for new contracts and freelance projects. If you have a backend challenge, I'd love to hear about it.