You will get a high-performance software written in Rust.
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Project details
Struggling with inconsistent freelancers and exhaustive management? As a certified Rust Software Engineer, I bring clarity and excellence to your projects.
Technologies and crates I'm comfortable with:
Back-end frameworks: actix-web, axum, hyper
Network: WebRTC, LibP2P, QUIC, WebSocket
Data scraping: voyager, crabler
Async runtimes: tokio, actix
Databases: sqlx, diesel, rusqlite, PostgreSQL, MySQL, SurrealDB, Firestore
CLI/TUI: clap, tui
Full-stack framework and web-to-app: tauri, dioxus, leptos
Containers and orchestration: Docker, Kubernetes
Columnar Databases: ClickHouse, Snowflake, Google BigQuery, Amazon Redshift
Languages: Rust first, C++, TypeScript/JavaScript, Python
DevOps Tools: Terraform, Jenkins, GitHub CI/CD
Security: OpenSSL, JWT, OAuth 2.0
Big Data: Apache Hadoop, Apache Spark
Observability: Prometheus, Grafana, ELK Stack
Communication: gRPC, tonic, GraphQL
Cloud Services: AWS, GCP, Azure
Streaming broker: Apache Kafka, RabbitMQ
Machine Learning: TensorFlow, PyTorch, Bern, Linfa
APIs for Generative AI: OpenAI API, Anthropic API, Hugging Face
LLMs and Adapters: OpenLLaMA, BERT, KALOSM, Mistral, Candle Transformers
BOOK A FREE CALL BEFORE PLACING AN ORDER!
Technologies and crates I'm comfortable with:
Back-end frameworks: actix-web, axum, hyper
Network: WebRTC, LibP2P, QUIC, WebSocket
Data scraping: voyager, crabler
Async runtimes: tokio, actix
Databases: sqlx, diesel, rusqlite, PostgreSQL, MySQL, SurrealDB, Firestore
CLI/TUI: clap, tui
Full-stack framework and web-to-app: tauri, dioxus, leptos
Containers and orchestration: Docker, Kubernetes
Columnar Databases: ClickHouse, Snowflake, Google BigQuery, Amazon Redshift
Languages: Rust first, C++, TypeScript/JavaScript, Python
DevOps Tools: Terraform, Jenkins, GitHub CI/CD
Security: OpenSSL, JWT, OAuth 2.0
Big Data: Apache Hadoop, Apache Spark
Observability: Prometheus, Grafana, ELK Stack
Communication: gRPC, tonic, GraphQL
Cloud Services: AWS, GCP, Azure
Streaming broker: Apache Kafka, RabbitMQ
Machine Learning: TensorFlow, PyTorch, Bern, Linfa
APIs for Generative AI: OpenAI API, Anthropic API, Hugging Face
LLMs and Adapters: OpenLLaMA, BERT, KALOSM, Mistral, Candle Transformers
BOOK A FREE CALL BEFORE PLACING AN ORDER!
Coding Expertise
Performance Optimization, SecurityWhat's included
| Service Tiers |
Starter
$450
|
Standard
$950
|
Advanced
$9,500
|
|---|---|---|---|
| Delivery Time | 3 days | 7 days | 60 days |
Number of Revisions | 0 | 0 | 0 |
Design Customization | - | - | - |
Content Upload | - | - | - |
Responsive Design | - | - | - |
Source Code | - | - | - |
Frequently asked questions
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KK
Ken K.
Jun 2, 2026
Next Phase Back End Engineer for Tofu
We had an excellent experience working with Kos and his team at Out of the Box Systems.
Over the course of our partnership, they became an important part of our backend engineering efforts and contributed significantly to several critical areas of our product. Their work included stabilizing integrations with external services such as QBO and Xero, improving the reliability of our backend systems, optimizing complex database queries, and helping move key engineering projects forward with a high level of autonomy.
The quality of their work, communication, and ownership were consistently strong. They were able to take on complex technical challenges independently, deliver meaningful improvements, and operate very much like embedded members of our internal engineering team.
We truly appreciate the work Kos and his team contributed to our company, and we would be happy to recommend them to anyone looking for strong backend engineering support.
Over the course of our partnership, they became an important part of our backend engineering efforts and contributed significantly to several critical areas of our product. Their work included stabilizing integrations with external services such as QBO and Xero, improving the reliability of our backend systems, optimizing complex database queries, and helping move key engineering projects forward with a high level of autonomy.
The quality of their work, communication, and ownership were consistently strong. They were able to take on complex technical challenges independently, deliver meaningful improvements, and operate very much like embedded members of our internal engineering team.
We truly appreciate the work Kos and his team contributed to our company, and we would be happy to recommend them to anyone looking for strong backend engineering support.
KK
Ken K.
Apr 28, 2026
Backup Back End Engineer for Tofu
We've been working with Kos and his team for about six months now, and they have become one of the main engineers on our backend team. What started as a contractor role has turned into something much more — we treat them as a full-time members of our engineering team.
Kos and his team delivered our Version 1 integration project ahead of schedule, handling QBO and Xero integrations, complex database optimizations, and API extraction logic almost entirely independently. They work very autonomously, have started leading projects, and are showing real leadership on our team, which has been great. We are looking forward to continuing this partnership long-term.
Kos and his team delivered our Version 1 integration project ahead of schedule, handling QBO and Xero integrations, complex database optimizations, and API extraction logic almost entirely independently. They work very autonomously, have started leading projects, and are showing real leadership on our team, which has been great. We are looking forward to continuing this partnership long-term.
GG
Gary G.
Feb 20, 2026
Back-end Development - Graphical Specialist
Out of the Box Systems matched me with an exceptional graphics developer, Yevhenii Avramenko, who demonstrated outstanding professionalism and deep conceptual mastery throughout the project. His contributions were critical to the project’s success.
GG
Gary G.
Feb 4, 2026
Rust/Python Implementation
RK
Roman K.
Jan 7, 2026
Times software
About Kostiantyn
Platform Engineer, AI, Secure Systems, Rust, C++ + 5 more languages
100%
Job Success
Batumi, Georgia - 12:12 am local time
100,000+ concurrent WebSocket connections -- in production. A 12-week roadmap shipped in 4.
30 senior engineers. Dedicated project teams, not rotating freelancers. Every engagement starts with a paid Discovery phase -- we scope the architecture before we write a line of code.
Not a fit: no-code workflows, or projects solvable with Zapier.
WHAT I BUILD
- High-Performance Backends: Production backends with actix-web, axum, and Tokio -- millions of requests/day, zero GC pauses. REST, GraphQL, WebSocket, and gRPC services for throughput and latency-sensitive workloads.
- Full-Stack Platforms: React, Next.js, TypeScript frontends with production backends -- SaaS, MVPs, and custom web applications from architecture to deployment. Designed for 1K to 100K concurrent users without a rewrite.
- Autonomous AI Agents: Agentic pipelines with OpenAI and Anthropic Claude -- lead qualification, data analysis, customer support running 24/7. Multi-step reasoning, error recovery, state persistence. 11+ projects for one client.
- Computer Vision: Object detection, tracking, real-time inference, OCR, document processing -- CUDA-optimized, deployed as production APIs or edge devices. Not Jupyter notebooks.
- Real-Time 3D & Visualization: WebGL and WebGPU rendering -- product configurators, data dashboards, architectural viewers at 60fps in-browser on mid-range hardware.
- Data Pipelines: Rust-native processing with Polars and DataFusion -- replacing Python/JavaScript bottlenecks. Kafka streaming, PostgreSQL persistence.
- Cloud & Infrastructure: AWS, GCP, Azure with Terraform and Kubernetes -- auto-scaling, zero-downtime deployments, infrastructure-as-code.
RECENT OUTCOMES
- Crypto trading platform dropping connections above 8,000 users. Rebuilt proxy in Rust, Tokio, Kubernetes -- 100,000 connections at under 10ms, zero crashes.
- GovTech blockchain payment router on Go. Rebuilt IAVL Tree in Rust -- 20–30% faster, Clutch-reviewed (Alex Kampa, AZKR Research).
- Recruitment team spending 4 hours daily on manual data entry. Built automated extraction and processing pipeline -- 95% reduction.
- Data analytics platform hitting memory limits in JavaScript. Replaced core with Rust and Polars -- 5x faster processing, 70% lower memory.
- Blockchain gaming 3D pipeline loading in 8+ seconds. Rebuilt within 4GB RAM budget -- 45% faster, Clutch-reviewed (Ruslan Varets).
TECHNOLOGIES
- Systems & Backend: Rust, C++, Python, TypeScript, actix-web, axum, Tokio, Node.js, WebAssembly
- Frontend: React, Next.js, TypeScript, Tauri, Dioxus
- AI & Agents: OpenAI, Anthropic Claude, Hugging Face, LangChain, RelevanceAI
- Graphics: WebGL, WebGPU, OpenGL, Vulkan, three.js, GLSL/WGSL shaders, bevy
- Vision: OpenCV, CUDA, PyTorch, TensorFlow, Keras, Mediapipe
- Data: Polars, DataFusion, PostgreSQL, Kafka, Snowflake, Apache Arrow
- Cloud & DevOps: AWS, GCP, Azure, Terraform, Kubernetes, Docker, GitHub Actions
- Networking: WebRTC, LibP2P, QUIC, WebSocket, gRPC
Delivery: Discovery → Architecture Review → Platform Build → Performance Testing → Production Deploy → Runbook Handoff. Fixed scope per phase.
This profile is for engineering teams building production platforms under real load. Send your project brief -- I'll reply within 48 hours to assess fit.
Steps for completing your project
After purchasing the project, send requirements so Kostiantyn can start the project.
Delivery time starts when Kostiantyn receives requirements from you.
Kostiantyn works on your project following the steps below.
Revisions may occur after the delivery date.
Initial Consultation and Requirement Gathering
We’ll discuss your project’s vision, key goals, and technical needs to ensure I fully understand the scope. This helps set a clear foundation for the development process.
Technology Stack and Architecture Discovery
I’ll work with you to explore your project’s needs in detail, ensuring we choose the right frameworks, databases, and dependencies. This discovery process helps guarantee we use the best tools for performance, scalability, and security.