Author profile
Daniel Killyevo
Founder & Technical Lead
Daniel Killyevo started Design Key with a vision to empower businesses with cutting-edge technology and tailor-made solutions. After years of experience in the tech industry, Daniel recognized the gap between clients' needs and available services. This realization led to the creation of Design Key, an agency that would bridge the divide and help clients achieve their goals with better-designed products.
Daniel is an accomplished technical leader with a Master's degree in Computer Science from Poltava National Technical University (2005-2011). Born to a Ukrainian mother and Tanzanian father in Tanzania and raised in Ukraine, he brings a unique global perspective to his work.
With over a decade of experience in software development and product design, Daniel has successfully delivered more than 50 web and mobile applications. He began his career as a software developer and went on to work with prominent companies such as Ciklum, Corrigo (Terminix), and JustEat, helping build more than 40 prototypes and MVPs for startups.
His expertise includes architecting complex cloud-based software solutions, API and data integrations, and building and scaling tech teams. As a seasoned entrepreneur, Daniel has gained invaluable experience working on personal startups and establishing two software agencies.
Articles
Written by Daniel
Design
Core Web Vitals in 2026: What Still Matters
Only 48% of mobile sites pass all three Core Web Vitals in 2026. INP is the metric most fail. And fast pages now correlate 3x with AI citations. Here is what still matters and what to ship.
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SaaS Pricing Models: Tiered vs Usage vs Hybrid
61% of SaaS companies will run hybrid pricing by year-end 2026. Pure per-seat is dying for AI products and pure usage-based is scary for buyers. Here is the 2026 update on which model fits which business.
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3 AI Agent Patterns That Ship in Production
Across audited engagements in 2026, three agent patterns ship reliably and one keeps failing. The three: routing, orchestrator-workers, evaluator-optimizer. The one: peer-to-peer multi-agent. Anthropic's guidance backs this. Here is when each fits and where each fails.
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Ecommerce Design: 2026 Conversion Patterns
Cart abandonment is stuck at 70.22% across 50 studies. Mobile is 80%. Ecommerce takes 69-77% of every ADA website lawsuit filed. The patterns that move the conversion needle in 2026 are not new - most sites still get them wrong.
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Why Custom Software Projects Fail in 2026
After 12 years and a few hundred audited projects, custom software project failure modes barely change. They take new shapes. AI-amplified tech debt is the 2026 entry, and it shows up in launches that look fine and decay in six months. Here are the ten.
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Custom MCP Servers: Build vs Buy in 2026
By March 2026 there are 10,000+ public MCP servers. Most teams should never write one. The 10% who should are usually the ones with auth, audit, or proprietary data needs that the catalog cannot meet. Here is the build vs buy decision.
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How to Hire a Web Design Agency in 2026
Portfolio screenshots are the worst way to evaluate a 2026 web design agency. AI search rewrote the rules, ADA lawsuits crossed 3,948 in 2025, and the line between a good launch and a lawsuit is process. Here is the framework we wish prospects used on us.
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Inside a 14-Week SaaS Sprint: Case Study
A real 14-week SaaS sprint, broken down week by week. The brief, the team, the Next.js + Supabase + Stripe + Resend stack, the AI-augmented engineering pattern, what shipped on time, what got cut, and the metrics we hit at launch.
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What an 'AI-Augmented Workflow' Actually Looks Like at an Agency
Most agencies talk about AI. Few will tell you what their actual day looks like. Here is the honest version from inside our shop in 2026 - the tools, the prompts, the moments it works, the moments it fails, and what it has done to the 2024 baseline.
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SaaS Website Design: Patterns That Convert in 2026
We tore down the 2026 SaaS sites that actually move pipeline - Linear, Vercel, Stripe, Cursor, Anthropic, Resend, Posthog. Here are the 12 patterns that show up across all of them, why they work, and how to use them without copying the surface.
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Top 10 Tech Stacks for SaaS in 2026
There is no single best SaaS tech stack in 2026. There are roughly 10 that win their category. This is the honest read on each: what they do well, who uses them, where they bite, and how much they cost to run.
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The Anthropic Claude Agent SDK in Plain English
Anthropic shipped the Claude Agent SDK on April 8, 2026 with Notion, Rakuten, Sentry, and Allianz already on board. Here is what it actually does, where it beats LangGraph and the raw API, and the use cases where it pays back fast.
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