Kozak Agency

Tech Stack:
• Backend: Node.js with Nest.js
• Database: PostgreSQL with RDKit integration, Prisma ORM
• REST, Swagger
• Unit & e2e tests

We offer:

• Cooperation with a stable company with well-established processes and a positive atmosphere
• Experience in project management of different levels of complexity, methodology, and approaches
• Flexible schedule: Mon-Fri (8 hours a day)
• 18 days of paid vacation; 15 days sick leave
• A decent level of remuneration with regular reviews of the results of cooperation
• Extensive loyalty program 

Шукаємо FullStack розробника (NodeJS + React + MongoDB) на аутстаф

- 3-6 років досвіду
- Досвід імплементації RBAC або подібних систем авторизації
- Домен - cybersecurity
- Гарна розмовна англійська

We offer:

• Cooperation with a stable company with well-established processes and a positive atmosphere
• Experience in project management of different levels of complexity, methodology, and approaches
• Flexible schedule: Mon-Fri (8 hours a day)
• 18 days of paid vacation; 15 days sick leave
• A decent level of remuneration with regular reviews of the results of cooperation
• Extensive loyalty program 

Tech Stack:
• Backend: Node.js with Nest.js
• Database: PostgreSQL with RDKit integration, Prisma ORM
• REST, Swagger
• Unit & e2e tests

We offer:

• Cooperation with a stable company with well-established processes and a positive atmosphere
• Experience in project management of different levels of complexity, methodology, and approaches
• Flexible schedule: Mon-Fri (8 hours a day)
• 18 days of paid vacation; 15 days sick leave
• A decent level of remuneration with regular reviews of the results of cooperation
• Extensive loyalty program 

Requirements:
• Strong experience with React Native and TypeScript
• Hands-on experience with Expo and Firebase
• Solid understanding of modern app architecture and clean code principles
• Ability to work with server-driven UI concepts
• Good English communication skillsSchedule:
• Ideally available from 1 PM to 9 PM Kyiv time for strong overlap with EST timezone (Toronto/New York)

Nice to have:
• Experience with weather or data-heavy apps
• Familiarity with CI/CD and mobile app deployment
• Understanding of performance optimization in mobile apps
 

We have a new request for ML engineer on a 6-months project.
Role: ML Engineer

Task: Develop an automated satellite verification platform for Agricultural subsidy programs.

Tech Stack: Python, PyTorch, Sentinel 1/2, TensorFlow, QGIS, GCP, Vertex AI, GIS, FastAPI, Google Earth, Presto, Clay, AlphaEarth

Seniority: Middle-Senior
Time zone: CET (EU)
Duration: 6+ months
Involvement: Full-time

Start date: Mid-late November 25.
English: Upper-Intermediate/Advanced
 

The project is an all-in-one workplace management platform that enables users to book desks and meeting rooms, schedule meetings, coordinate teams, and manage visitors. We are looking for an experienced backend engineer to help scale our PHP-based SaaS platform and build new features across a large distributed system.

RESPONSIBILITIES

• Build highly performant, scalable PHP-based SaaS applications.
• Architect, develop, and optimize backend services using PHP 8.3 and Symfony 7.2 (or Laravel if preferred).
• Design, build, and maintain RESTful APIs consumed by web and mobile applications.
• Develop backend solutions interacting with AWS-based services, PostgreSQL, Redis, and distributed systems.
• Collaborate closely with backend engineers, DevOps, product managers, and designers.
• Contribute to architectural decisions and challenge technical approaches when needed.
• Write clean, maintainable, secure, and testable backend code.
• Troubleshoot and resolve complex technical issues across services and infrastructure.
• Write and maintain automated tests to ensure product quality.
• Create and maintain technical documentation for backend services and APIs.
   

SKILLS AND EXPERIENCE

• 5+ years of experience in backend software engineering.
• Strong expertise in PHP and the Symfony framework (Laravel knowledge or willingness to learn is a plus).
• Experience building large-scale, distributed, consumer-facing web applications.
• Solid understanding of REST API architecture, microservices, and backend best practices.
• Strong grasp of MVC, SOLID principles, clean architecture, and design patterns.
• Experience with PostgreSQL, Redis, and performance optimization.
• Experience with AWS services, Kubernetes, Docker, or other cloud-native tooling is a strong plus.
• Experience with multi-tenancy is a bonus.
• Familiarity with unit testing, automated testing, and CI/CD pipelines (Jenkins/GitHub Actions).
• Ability to work in Scrum/Agile processes and adapt quickly based on feedback.
• Upper-intermediate+ English for communication and documentation.
• Excellent collaboration and communication skills.
• BSc in Computer Science, Software Engineering, or a related technical field.
   

Our Current Tech Stack

• Backend: PHP 8.3, Symfony 7.2, API Platform, Node.js (Lambdas)
• Databases: PostgreSQL, Redis (ElastiCache)
• Cloud: AWS (20+ services), Kubernetes, Docker
• Tools: Jira, Jenkins, GitHub, Automated Testing
• AI tools: Cursor, ChatGPT, Junie for debugging and test generation

Task: Develop an automated satellite verification platform for Agricultural subsidy programs.

Tech Stack: Python, PyTorch, Sentinel 1/2, TensorFlow, QGIS, GCP, Vertex AI, GIS, FastAPI, Google Earth, Presto, Clay, AlphaEarth,

Seniority: Middle-Senior
Time zone: CET (EU)
Duration: 6+ months
Involvement: Full-time
English: Upper-Intermediate/Advanced

We are seeking a skilled Full-Stack Developer with strong expertise in Java and Spring framework. The ideal candidate should be comfortable working on both front-end and back-end development, and have a solid understanding of database management. You will be responsible for building scalable web applications and enhancing existing features. If you are a problem solver who loves coding and can work collaboratively in a team environment, we want to hear from you!

The company’s focus on identity management, governance, and privileged access management as critical to protecting digital and physical identities across various domains, including emerging AI agent identities.

The team culture emphasizes continuous learning, including adoption of AI development tools like Microsoft Copilot and Cursor, aiming for developers to grow their skills and take on increasing responsibilities.

The role offers long-term engagement with an expectation of stable tenure, providing opportunities to work on end-to-end identity solutions rather than narrow components

Requirements:
– Teams app framework (tabs/bots/message extensions)
– Graph API and Microsoft 365 integration

We offer:

• Cooperation with a stable company with well-established processes and a positive atmosphere
• Experience in project management of different levels of complexity, methodology, and approaches
• Flexible schedule: Mon-Fri (8 hours a day)
• 18 days of paid vacation; 15 days sick leave
• A decent level of remuneration with regular reviews of the results of cooperation
• Extensive loyalty program 

Requirements:
– Solid experience in Python (Django)
- Strong Azure experience
– LLM integration, integration with Jira or similar systems via REST APIs, APIs, data layer
– plus IaC, CI/CD and observability on Azure (nice to have)

We offer:

• Cooperation with a stable company with well-established processes and a positive atmosphere
• Experience in project management of different levels of complexity, methodology, and approaches
• Flexible schedule: Mon-Fri (8 hours a day)
• 18 days of paid vacation; 15 days sick leave
• A decent level of remuneration with regular reviews of the results of cooperation
• Extensive loyalty program 

Start: ASAP (really urgent)
Duration: 6 months + possible extension
Workload: Full-time (9 AM – 6 PM UK time)
Device: Mac required

Tech Stack:

Backend:
 • Node.js
 • AWS (SNS, SQS, Lambda, EventBridge)
 • Event-driven architecture
 • MongoDB
 • Serverless
 • Terraform
 • GitHub Actions

Frontend:
 • React
 • Redux
 • Next.js
 • MaterialUI

Type: Long-term, Full-time
 

We are looking for a skilled Python Developer to join our team and work on a core product that essentially serves as the main library/framework used by our client. There are no external frameworks — the project itself is the framework, and your work will directly influence its architecture, performance, and reliability.
 

You will work closely with the team lead and engineering team, focusing on high-performance Python development, concurrency, and efficient data handling.
 

Tech Stack

• Python (advanced)
• asyncio
• Multithreading & Multiprocessing
• Databases: PostgreSQL (primary), SQLite (local)

Project start: ASAP
Duration: Until the end of March (with a possibility of extension)
Workload: Full-time
English: B2

To summarize:
We are currently looking for a Senior Ruby on Rails Developer with 5 years of experience. We require full-time availability and strong communication skills. The role is within one of our largest projects - a B2B platform. The project is split into maintenance and new features work.

Summary:
The main function of this role is to work as a full-stack .NET Developer within a financial technology environment, supporting the transition of applications to a cloud-based infrastructure while extending existing systems to accommodate new entities.We are working with a UK-based financial client on a large-scale .NET platform migration. We’re implementing business logic, optimising it to .NET 8 and one of the latest Angular versions, and moving to an event-driven microservices architecture using Kafka.

Main Responsibilities:

• Develop full-stack solutions using .NET and C#.
• Implement solid design principles in software development.
• Collaborate closely with business analysts and other developers to deliver solutions without dedicated QA teams.
• Support multiple applications within the banking and risk management domains.
• Participate in the migration of apps to containerised cloud solutions.
• Work on extending systems to support merged business operations.
• Engage in unit and integration testing as part of the development process.
   

Key Requirements:

• Proficient in .NET and C# (min. 8+ years of experience)
• Experience with fullstack development, including some experience with Angular
• Familiarity with document-based databases.
• Knowledge of event-based messaging frameworks (Kafka) & event-driven architecture
• Experience with cloud services and containerization.
   

Nice to Have:

• Prior experience in the banking or financial services sector.
• Experience with MongoDB or similar environments.

Other Details:
Environment: .NET, C#, some Angular, MongoDB, moving towards cloud solutions (Azure)Team Structure: Full Stack Developers working closely with Business AnalystsInterview Process: 2 stages, including a technical test, estimated to take 2-5 hours to complete

Our client is a U.S.-based real estate technology company that powers a high-volume enterprise platform for real estate professionals. They are looking for a development partner to scale and enhance a mission-critical data integration system responsible for synchronizing listings, processing large datasets, and maintaining reliable data flows across numerous external providers.

We are looking for a Senior Backend Engineer (Node.js) with deep experience building data-intensive backend systems, distributed processing pipelines, and integrations with third-party APIs. This role focuses on improving the performance, maintainability, and reliability of a large-scale Node.js platform that ingests, normalizes, and processes real estate data.

The engineer will collaborate closely with other backend developers to troubleshoot complex issues, optimize data processing workflows, and build scalable, production-ready backend services.This is a core backend role with significant ownership of key system components.

Key Responsibilities
- Develop, scale, and maintain backend services for large-scale data ingestion and synchronization.
- Build and optimize job queue systems and asynchronous processing pipelines.
- Design and maintain ETL-style data transformation flows to normalize large and diverse datasets.
- Implement automated data validation, enrichment, and monitoring mechanisms to ensure data quality.
- Troubleshoot and resolve issues related to data integrity, performance, and external provider integrations.
- Optimize PostgreSQL queries, schemas, and data access patterns for high-volume operations.
- Collaborate closely with engineering team members to improve overall architecture and system reliability.

Requirements
- Strong hands-on experience with Node.js in high-load, production environments.
- Deep understanding of asynchronous workflows, queues, workers, and distributed processing patterns.
- Proven experience building data integration / ETL / data normalization systems.
- Strong proficiency with PostgreSQL, including schema design and query optimization.
Experience working with REST APIs, third-party integrations, and large datasets.
- Ability to debug complex data issues and implement monitoring for data consistency and performance.
- Strong problem-solving skills, attention to detail, and ability to work independently on mission-critical system components.
- Excellent communication skills and ability to collaborate within a senior engineering team.
- Fluent English for calls with the client.

Nice to Have
Experience with real estate data standards (MLS, IDX, RETS).
Experience with data synchronization strategies across distributed systems.
Background in maintaining high-availability backend processing systems.
Prior experience with Cloud environments, containerization, or distributed architectures.Duration: 12+ months

Interview Stages:
English check
Client’s CV screening
Interview with the Team Lead on the client’s side

Working hours: CET time zone