Pavel Zaitsau
Tech Lead · AI / ML Systems · .NET

Pavel Zaitsau

Builds production RAG & LLM systems. 15+ years across .NET, data-heavy backends, and team leadership.

Open to opportunities · 1k+ GitHub contributions/yr · 8,500+ km on Strava · 600+ Vivino ratings
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Experience

9 roles · 15 years · every entry shipped to production

Tech Lead, AI / ML @ ADF Solutions, Inc 2022 - 2026

Forensic data analysis software appliance for law enforcement and cybersecurity teams. Designed the system from scratch and led its shift to AI-powered analysis - multiple ML pipelines and an on-prem RAG stack over seized-device data.

  • Built multiple ML / AI and algorithm-driven data processing pipelines in Python on Apache Airflow - ingestion, enrichment, extraction, and indexing over large seized-device datasets
  • Shipped a production on-prem RAG system with an LLM-agnostic backend - swap models and providers without touching the app; retrieval entirely in Elasticsearch with cross-encoder reranking and no separate vector database to operate; orchestrated in .NET with Semantic Kernel, answers cited to source, full data isolation and audit logging
  • Tech lead for 5-9 engineers; system design from scratch - architecture, delivery, code review, and engineering standards
  • Owned CI/CD end to end - build, test, and release pipelines for an air-gapped appliance, including reproducible offline builds and versioned deployments
  • Shipped ML modules: speech-to-text, OCR, image classification, object detection, scene classification, person and age detection, document understanding, summarization, and social graph analysis
  • Built the platform underneath: air-gapped Kubernetes appliance, .NET microservices and APIs, and the Elasticsearch indexing layer - ingestion, annotation, and case management
RAG LLMs LLM-agnostic Semantic Kernel Hugging Face Transformers PyTorch TensorFlow OCR Computer Vision Object Detection Speech-to-Text Social Graph Analysis Elasticsearch Python .NET Kubernetes Apache Airflow Azure Docker
Co-Founder @ Góra Print 2025 - present

Pet business building custom 3D-printed physical terrain models from open geospatial data. Combines cartographic data processing, terrain modeling, and small-scale manufacturing into an end-to-end product.

  • Built a Python pipeline that turns open geospatial data (FABDEM, OpenStreetMap) into terrain models
  • Built a toolchain to prep models for 3D printing
  • Added an LLM-driven order flow: intake, payment, shipping
PythonFABDEMOpenStreetMap Transformer ModelsLLMs3D printing
Software Engineer @ Ryanair 2021 - 2022

Schedule management system for one of Europe's largest low-cost carriers (100M+ passengers/yr). High-volume, latency-sensitive backend services.

  • Designed microservices for flight scheduling at airline scale
  • Migrated .NET 4.7 to .NET 6 with zero downtime
  • Cut API response times through performance work
  • Improved CI reliability and deploy frequency
  • Built internal WPF tooling for scheduling operations
.NET 6MicroservicesAWSDockerPostgreSQLJenkinsWPF
Tech Lead @ VEB Technologies 2020 - 2021

Integrated B2B fintech platform for a major Belarusian bank, built on a private cloud with 50+ interconnected microservices.

  • Led development and QA for a B2B banking platform
  • Designed architecture across 50+ microservices on private cloud
  • Managed 5+ engineers; set up code review and testing
  • Owned infra, CI/CD, and releases
.NET CoreMicroservicesKubernetesDockerPostgreSQLMongoDBRedisRabbitMQELK Stack
Senior Software Engineer @ Domino's Pizza UK & Ireland 2019 - 2020

Multi-market high-performance e-commerce platform serving millions of orders across UK and Ireland.

  • Shipped features on a high-traffic e-commerce backend
  • Worked with stakeholders and QA across markets
  • Mentored engineers; drove code quality
.NET CoreAzureKubernetesDockerMicroservices
Senior Software Engineer @ Coral Technology 2017 - 2019

Cloud-based B2B platform for media distribution and ad sales, serving broadcast industry clients.

  • Built modules for a cloud B2B media platform (Coral MSP)
  • Built a load-testing system from scratch
  • Drove code quality: reviews, UI tests, profiling
  • Delivered features for the ad sales system
.NET FrameworkAzureSQL ServerRedisRabbitMQELK StackJenkins
Senior Software Engineer @ Wolters Kluwer 2014 - 2017

SaaS governance, risk, and compliance (GRC) platform and HITRUST CSF integrated risk assessment tool.

  • Built core GRC components: logging/search, encrypted data store
  • Led architecture and code reviews; drove CI/CD and test automation
  • Owned releases and support for the HITRUST CSF platform
.NET FrameworkSQL ServerLuceneSeleniumNuGet
Tech Lead @ Belarusian-Russian University 2012 - 2017

Public website and internal subsystems - built from scratch. Full ownership over 5 years: architecture, team, infrastructure, and delivery.

  • Built the web portal and internal systems from zero: CMS, event hub, asset and schedule management
  • Led the team across the full lifecycle
  • Set up load balancing and CI/CD for high availability
.NET FrameworkSQL ServerIISWindows ServerPowerShellTeamCity
Key Developer @ Netologic Inc. (Investars) 2011 - 2014

Investment analytics platform and mobile applications. Early-career, full-stack engineering.

  • Delivered features for an investment analytics platform
  • Built the mobile backend; worked across the codebase
.NET FrameworkSQL ServerJavaScriptNode.jsMongoDBiOSTeamCity

GitHub Activity

Contributions over the last year

Tech Stack

Tools and platforms I work with day to day.

AI / ML

RAG LLMs LLM Orchestration LLM-agnostic Backends Semantic Kernel Vector Search / Embeddings Hybrid Retrieval Cross-encoder Reranking Fine-tuning NLP On-prem Model Serving Hugging Face Transformers PyTorch TensorFlow OCR / Document Understanding Computer Vision / Object Detection Speech-to-Text

Languages

C# / .NET Python JavaScript Bash

Backend

Microservices REST APIs Apache Airflow

Infrastructure & Cloud

Kubernetes Docker Azure AWS

Data & Messaging

Elasticsearch PostgreSQL SQL Server Redis MongoDB RabbitMQ

CI / CD

GitHub Actions Jenkins TeamCity

Leadership

How I lead teams - consistent, hands-on, delivery-focused

5-9
Engineers Managed

Direct team at ADF and VEB Technologies. Covered hiring, mentoring, performance alignment, and engineering culture. Never just a title - always in the codebase with the team.

3×
Teams Built from Zero

Assembled and onboarded engineering teams at VEB Technologies, Belarusian-Russian University, and Netologic - each time from no team to full delivery.

100%
Hands-On Delivery

Player-coach at every leadership role. Architecture decisions backed by code written, not slides presented. Code reviews aren't delegated - they're the job.

Beyond the Code

What I get up to away from the keyboard

🏃

Running

Long-distance and trail running - 780 activities and 8,500+ km logged. Keeps me consistent, clear-headed, and outdoors.

Strava profile →
🍷

Wine

A curious wine enthusiast - 600+ wines rated. Tasting, tracking, and learning the stories behind regions, vintages, and producers.

Vivino profile →
✈️

Travel

Remote-first for years. I enjoy working across timezones, seeing new places, and adapting quickly to new contexts.

🏂

Snowboarding

Winters on the mountain whenever I can - reading the terrain, committing to the line, and enjoying the ride.

Let's talk LinkedIn GitHub