Aleksei K.
Senior Full-Stack .Net | AI Integration, Umbraco
Full-stack developer, 16+ years in C# and .NET, React and TypeScript on the front end. I build SaaS platforms and business applications, add AI features that do real work, and take over systems other teams started. You hand me a task. We agree on the scope, the deadline and what "done" looks like. On that date you get it back built, tested and debugged. You don't have to manage the work in between. What I build SaaS platforms: multi-tenant data, roles, subscriptions, payments, admin dashboards AI inside your product: LLM integration, AI agents with tool calling, MCP servers, RAG over your documents Business systems: bookings, inventory, reporting, replacing spreadsheets Takeovers: audits, fixes, .NET Framework to .NET 8+ migrations, Umbraco 7 to 18 upgrades How I work I build with AI agents daily: Claude Code and Codex with multi-agent orchestration, while I own the architecture and review and test every change. Your repo, your branching, your ticket tracker, your staging. I can work behind the scenes or join client calls as part of your team. If the scope grows, you hear about it before it costs you anything. Stack: C#, ASP.NET Core, REST APIs, Node.js, React, TypeScript, Angular, Blazor, PostgreSQL, SQL Server, Azure, Docker, OpenAI and Claude APIs, Umbraco, Stripe. Projects include Lawify, a multi-tenant SaaS for US law firms, and sites for Twinings (UK), The Rocks and Darling Harbour (Sydney). Based in Ukraine, European hours. Backup power and internet; working without interruption since 2022. Send me a short description of your product or task, and I'll tell you how I'd approach it.
Earnings and projects
Last 6 months ÷ 6
Last 6 months: $22k
Billed in all: $631,382$631k
$3.1k in the last 6 months
Across 183 contracts
Earnings, last 30 days
Skill rankings: Top 4% in REST API
Ranked by MRR among everyone on Upwork with the skill.
- #9Umbraco161 freelancers · 🇺🇦 #3Top 6%🇺🇦#3 of 7
- #21LLM Agent Development242 freelancers · 🇺🇦 #3Top 9%🇺🇦#3 of 16
- #48Blazor656 freelancers · 🇺🇦 #7Top 7%🇺🇦#7 of 31
- #122ASP.NET Core2,272 freelancers · 🇺🇦 #13Top 5%🇺🇦#13 of 120
- #189REST API5,062 freelancers · 🇺🇦 #17Top 4%🇺🇦#17 of 346
- #263Microsoft Azure4,659 freelancers · 🇺🇦 #17Top 6%🇺🇦#17 of 149
- #320SaaS Development5,201 freelancers · 🇺🇦 #21Top 6%🇺🇦#21 of 209
- #368Docker8,761 freelancers · 🇺🇦 #42Top 4%🇺🇦#42 of 659