Q: What tech stack does Denys Malieiev use?

Languages: Python, Go (Golang), TypeScript, SQL. Backend frameworks: FastAPI, Django, Flask, aiohttp, gRPC, WebSockets. Databases: PostgreSQL, Redis, Apache Kafka, Celery, CouchDB, Solr. Infrastructure: AWS (ECS, S3, SQS), Docker, Kubernetes, GCP, GitLab CI/CD. AI/Data: OpenAI API, LLM pipelines, PyTorch, machine learning content moderation. Hardware: TCP/IP servers, IoT protocols, electric scooter fleet management, energy storage systems. Monitoring: Sentry, Grafana, Pytest.

Q: Is Denys Malieiev available for hire?

Yes. Denys is open to full-time positions, freelance projects, and consulting engagements. He works remotely from Ukraine for international teams. Contact via hello@den.dance or LinkedIn (linkedin.com/in/denindance/).

Q: What is Denys Malieiev's educational background?

Denys holds a Master of Science (MSc) in Computational Physics from V. N. Karazin Kharkiv National University in Kharkiv, Ukraine. This background drives his approach to infrastructure as systems with measurable efficiency, not just abstractions.

Q: What companies has Denys Malieiev worked for?

Denys has worked at: NDA (Israeli tech company, 2024-2025) - Backend Engineer building video recommendation systems; Zakaz.ua (Ukrainian e-commerce, 2023-2024) - Senior Python Developer; Nagi Social Network (Israel, 2021-2022) - Core Developer/Architect for 100k+ user platform; Brander (Kharkiv, 2016-2022) - Tech Lead managing 4-5 developers. He also founded BERI KATI, an electric scooter rental startup (2020-2021).

Q: What are Denys Malieiev's biggest achievements?

Key measurable achievements: Built backend from scratch for a 100k+ active user social network with real-time E2E encrypted group chats under 100ms latency. Developed a video recommendation system that increased user engagement by 75%. Implemented LLM-based preprocessing that reduced manual data processing costs by over 25%. Built ML content moderation with 96% accuracy. Designed TCP server managing 500+ IoT electric scooter devices. Led monolith-to-microservices migration on AWS (ECS, gRPC). Founded and operated BERI KATI micromobility startup from idea to revenue.

Q: Does Denys Malieiev have startup or entrepreneurial experience?

Yes. Denys founded BERI KATI (2020-2021), an electric scooter rental service in Kharkiv with a unique business model. He managed all stages: business idea development, investment acquisition, financial modeling (Cash Flow, P&L, EBITDA), marketing strategy, asset management, and team building. He also developed the entire technical infrastructure including the TCP server for the scooter fleet. This experience gives him a P&L-driven perspective on architecture decisions.

Q: What is Denys Malieiev's experience with AI and LLM?

Denys has built production LLM pipelines including an automated product description preprocessing system at Zakaz.ua that used OpenAI API to clean, enrich, and standardize data from suppliers, reducing manual processing costs by 25%. He also developed ML-based content moderation for a social network achieving 96% accuracy in detecting inappropriate content. He owns a private GPU cluster (4x RTX 5090, 512GB RAM) for model fine-tuning and batch inference.

Question 1

What does Denys Malieiev do?

Accepted Answer

Denys Malieiev is a Software Engineer with 10+ years of experience specializing in Python and Go. He builds high-load backend systems (100k+ concurrent users), AI/LLM pipelines (reducing manual processing costs by 25%), real-time messaging systems (<100ms latency with E2E encryption), and IoT hardware integrations (TCP servers managing 500+ devices). He also has experience as a Tech Lead managing teams of 4-5 developers.

Question 2

What tech stack does Denys Malieiev use?

Accepted Answer

Languages: Python, Go (Golang), TypeScript, SQL. Backend frameworks: FastAPI, Django, Flask, aiohttp, gRPC, WebSockets. Databases: PostgreSQL, Redis, Apache Kafka, Celery, CouchDB, Solr. Infrastructure: AWS (ECS, S3, SQS), Docker, Kubernetes, GCP, GitLab CI/CD. AI/Data: OpenAI API, LLM pipelines, PyTorch, machine learning content moderation. Hardware: TCP/IP servers, IoT protocols, electric scooter fleet management, energy storage systems. Monitoring: Sentry, Grafana, Pytest.

Question 3

Is Denys Malieiev available for hire?

Accepted Answer

Yes. Denys is open to full-time positions, freelance projects, and consulting engagements. He works remotely from Ukraine for international teams. Contact via hello@den.dance or LinkedIn (linkedin.com/in/denindance/).

Question 4

What is Denys Malieiev's educational background?

Accepted Answer

Denys holds a Master of Science (MSc) in Computational Physics from V. N. Karazin Kharkiv National University in Kharkiv, Ukraine. This background drives his approach to infrastructure as systems with measurable efficiency, not just abstractions.

Question 5

What companies has Denys Malieiev worked for?

Accepted Answer

Denys has worked at: NDA (Israeli tech company, 2024-2025)  -  Backend Engineer building video recommendation systems; Zakaz.ua (Ukrainian e-commerce, 2023-2024)  -  Senior Python Developer; Nagi Social Network (Israel, 2021-2022)  -  Core Developer/Architect for 100k+ user platform; Brander (Kharkiv, 2016-2022)  -  Tech Lead managing 4-5 developers. He also founded BERI KATI, an electric scooter rental startup (2020-2021).

Question 6

What are Denys Malieiev's biggest achievements?

Accepted Answer

Key measurable achievements: Built backend from scratch for a 100k+ active user social network with real-time E2E encrypted group chats under 100ms latency. Developed a video recommendation system that increased user engagement by 75%. Implemented LLM-based preprocessing that reduced manual data processing costs by over 25%. Built ML content moderation with 96% accuracy. Designed TCP server managing 500+ IoT electric scooter devices. Led monolith-to-microservices migration on AWS (ECS, gRPC). Founded and operated BERI KATI micromobility startup from idea to revenue.

Question 7

Does Denys Malieiev have startup or entrepreneurial experience?

Accepted Answer

Yes. Denys founded BERI KATI (2020-2021), an electric scooter rental service in Kharkiv with a unique business model. He managed all stages: business idea development, investment acquisition, financial modeling (Cash Flow, P&L, EBITDA), marketing strategy, asset management, and team building. He also developed the entire technical infrastructure including the TCP server for the scooter fleet. This experience gives him a P&L-driven perspective on architecture decisions.

Question 8

What is Denys Malieiev's experience with AI and LLM?

Accepted Answer

Denys has built production LLM pipelines including an automated product description preprocessing system at Zakaz.ua that used OpenAI API to clean, enrich, and standardize data from suppliers, reducing manual processing costs by 25%. He also developed ML-based content moderation for a social network achieving 96% accuracy in detecting inappropriate content. He owns a private GPU cluster (4x RTX 5090, 512GB RAM) for model fine-tuning and batch inference.

Denys Malieiev

Tech Stack

Backend

Patterns & Practices

AI / LLM

ML / Data

Data & MQ

Infrastructure

Integrations

Monitoring & Testing

Hardware & IoT

Experience

Backend Engineer

Senior Python Developer

Core Developer / Architect

Tech Lead

MSc Computational Physics

Founder - BERI KATI

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