Denys Zaichenko

Forward Deployed Engineer · Porto, Portugal

I am a Forward Deployed Engineer based in Porto. I work directly with the owner or the team, learn how the business really runs, and ship the software it needs. There is no account manager in between: the person who understands the problem is the person who builds the answer.

Most developers ask for a spec. I start with how the work is really done, what a failure costs and where the real bottleneck is. For one client, that turned a 2–3 week process into 2–3 minutes.

What I work on

Web apps and SaaS
Products and internal systems with payments, roles and clean data access.
AI agents
Chatbots, document extraction and agents that act inside your systems.
Fixing AI-built apps
Security and reliability work on apps that already have real users.
Automation
Workflows and data pipelines that replace manual steps.

What you can check yourself

What clients say

5.0 / 5
Comprehensive security assessment and bug fix for new website. Worked very quickly and jumped on a video call to talk me through the changes and next steps. Was super impressed and would 100% work with him again. Thanks a million!
Cybersecurity Specialist: Security Review of a Lovable-Built Web App (1-Day Engagement) · Oct 2026
- Committed to Quality
- Solution Oriented
- Clear Communicator
5.0 / 5
Fantastic work. We have finished the padel app, and I want to sincerely thank you for everything.
You were tireless throughout the process, always patient, highly professional, and extremely effective. You solved every issue that came up, took initiative whenever needed, and helped move the project forward with great commitment and quality.
It was a real pleasure working with you. Your technical skills, attitude, and ability to understand the project made a big difference.
Thank you again for the excellent work.
Padel Community App MVP – Portugal · Jun 2026
- Committed to Quality
- Solution Oriented
- Professional
5.0 / 5
Excellent developer! High-quality delivery and great communication on two of my personal projects. He is efficient, professional, and easy to work with. Highly recommended!
Full-Stack Dev (Python/Next.js): End-to-End SaaS Platform · Mar 2026
- High-Quality Delivery
- Great Communication
- Efficient
5.0 / 5
Denys is a great specialist, and he always does more than required! Very highly recommended!
Technical Strategy & Architecture Roadmap for AI-powered MVP · Jan 2026
- Committed to Quality
- Solution Oriented
- Clear Communicator
5.0 / 5
Full-Stack Dev (Python/Next.js): Pricing Intelligence Platform
Mar 2026
- Solution Oriented
- Clear Communicator
- Accountable for Outcomes

Selected work

Property document automation
Real-estate document service for property sales
Property certificates in 2–3 minutes instead of 2–3 weeks.
2–3 minper certificate, instead of 2–3 weeks
Live-broadcast audio quality control
Live-broadcast audio quality control for a media operations team
Audio faults now alert the moment they happen; checking used to be manual.
1 hourof readings kept on the site machine during a network outage; events for 24 hours
Travel price intelligence
Package-holiday price benchmarking for a travel agency, EU market
Competitor package prices, collected on schedule by jobs that recover from outages.
~5×dates collected per minute on one site after dropping the browser (8 → 43)

All work

Latest articles

All articles

How I write

Numbers in my articles come from my own tests or from a named source, and each post shows when it was published.

If something is wrong, write to me and I will correct it.

Get in touch

The fastest way to reach me is email. yes@madsalt.tech