Kozak Agency

Our client is seeking a Mid-Level Java Engineer to strengthen their product engineering function and help advance a cloud-based platform serving large-scale business clients. This role combines hands-on backend development, close collaboration with distributed engineering teams, and operational support aligned with US business hours.

Schedule
Core working hours are 14:30–22:30 CET

Key Duties
 • Contribute directly to backend and platform development within the client’s engineering organization
 • Collaborate closely with internal developers on ongoing initiatives, implementation tasks, and technical improvements
 • Provide technical support coverage for end customers during US daytime operations
 • Track, investigate, and address high-priority incidents occurring beyond standard European working hours
 • Take part in recurring team syncs, online collaboration sessions, and community-oriented engineering activities
 • Engage with the broader developer ecosystem surrounding the client’s product landscape
 • Support the continued evolution of the SaaS platform by:
 • Connecting with customer ERP environments to extract and process business data
 • Interpreting data flows and helping generate actionable outputs for customers
 • Designing, developing, and maintaining application features across the platform

Required Background
 • 3 to 5 years of commercial experience in Java backend development
 • Strong command of object-oriented programming principles and core Java concepts
 • Practical experience with Spring Boot and the design/build of REST APIs
 • Working knowledge of SQL and relational database systems
 • Ability to operate with a high level of ownership during late-shift or non-standard working hours
 • Strong communication skills and the ability to collaborate effectively in remote, multicultural teams
 • Professional-level English, both written and spoken

Preferred Qualifications
 • Experience integrating software with ERP platforms
 • Previous involvement in SaaS product engineering
 • Familiarity with CI/CD practices and container-based development or deployment environments
 • Exposure to AWS or similar cloud ecosystems
 • Background in customer support, production issue handling, or client-facing technical assistance

Location: any
Start: ASAP
Duration: long-term (with potential extension)
Engagement: Full-time
English: B2+

The mission:
Extending the existing API to support self-service features for a new recruitment/hr application.

Requirements:
- Strong Ruby on Rails expertise: Deep experience in scaling and expanding API endpoints.
- React Native (Bonus): Skills in RN are a huge plus and will allow for more flexible task distribution.
- Availability: Ready to start immediately.

Recruitment Process:
1) Introductory Call (15 min): A quick chat to put a face to the name and discuss the role.
2) Case Study: A technical task with specific requirements. Note: This takes approximately 8 hours and must be completed within a 9 AM – 5 PM window.
3) Technical Interview: A deep dive into the case study.
4) Culture Fit Interview: A final conversation with the company's CEO

Searching for an Ember Developer with experience in JavaScript (ES6+), TypeScript, HTML5, and CSS3.

English: B2
Location: Ukraine & Europe

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:

• 7 years total
• 3+ yrs - Next.js
• 5+ yrs - Node.js (Nest), Typescript
• 1+ year of experience with AI domain
• Experience with Clickhouse preferable

An AI platform for YouTube creators that analyzes channels and competitors, searches for viral ideas, generates video scripts and engaging thumbnails, prepares SEO-optimized titles and descriptions, analyzes retention and CTR, provides detailed channel analytics, offers AI agents for content creation, includes a Telegram bot and web app for management, and facilitates content planning.

Core responsibilities:

• Support and development of the ClickHouse scraping pipeline,
• Monitoring core platform logs,
• Improving the current architecture,
• Developing new features.

Work directly with CEO and CTO with no project managers, well defined tasks - tasks are set in chat Strong ownership; knowledge of architecture patterns.

This is a hands-on engineering role focused on building a fast, reliable, and user-friendly interface for DeFi workflows. You will work closely with backend engineers and product stakeholders to deliver production-ready features for real users.

Responsibilities:
Frontend Development

• Own and maintain the frontend application built with Next.js, React, and TypeScript
• Build scalable and high-performance interfaces for DeFi workflows, dashboards, and portfolio views
• Implement wallet connectivity and transaction flows
• Maintain strong standards for code quality, performance, testing, and maintainability

Web3 & Data Integration

• Translate complex on-chain data into clear user-facing product experiences
• Integrate blockchain data from RPC endpoints, event logs, indexed sources, and subgraphs
• Work with DeFi protocols and yield-related products
• Ensure correct handling of token decimals, pricing logic, balances, APY calculations, and other financial data

Product Development

• Build features such as portfolio tracking, transaction history, yield opportunities, delegation flows, and dashboard analytics
• Collaborate on product decisions and help shape intuitive UX for complex blockchain functionality
• Improve real-time data handling and frontend performance

Collaboration

• Work closely with backend engineers on APIs, data models, and system design
• Participate in code reviews, technical discussions, and architecture decisions
• Contribute to scalability and long-term engineering standards

Tech Stack

• Frontend: Next.js, React, TypeScript
• Blockchain: Viem, Ethers, smart wallet integrations
• Database: PostgreSQL, Prisma
• UI / Styling: Tailwind CSS, charting libraries
• Data Fetching: SWR
• Infrastructure: GitHub Actions, Docker, cloud hosting
• Blockchain Scope: EVM-compatible chains
• Protocol Integrations: Lending, swapping, yield, and routing protocols

Requirements

• 4+ years of experience building Web3 or crypto-native products
• Strong experience shipping production applications used by real users
• Strong proficiency in TypeScript, React, and Next.js
• Experience working with on-chain data, including RPC, logs, subgraphs, and multicall
• Strong understanding of wallet integrations, transaction lifecycle, gas mechanics, and token standards
• Familiarity with DeFi primitives such as lending, liquidity pools, swaps, vaults, and yield strategies
• Ability to turn complex blockchain data into intuitive product experiences
• Strong ownership mindset and ability to work independently in a fast-moving environment

Nice to Have

• Experience working at a DeFi, crypto infrastructure, analytics, or exchange product
• Familiarity with smart wallet infrastructure
• Experience with typed signing standards such as EIP-712
• Experience building financial dashboards or real-time data-heavy applications
• Contributions to Web3 open-source projects

What Success Looks Like

• A stable and high-quality frontend application that makes complex DeFi workflows easy to use
• Accurate and reliable presentation of on-chain portfolio and yield data
• Smooth wallet and transaction UX across multiple EVM chains
• Strong collaboration with backend and product stakeholders to deliver production-ready features quickly

Requirements:
• 5+ years of experience with Java (Spring / Spring Boot)
• Strong expertise in WebRTC protocols and architecture
• Solid experience with VoIP / SIP / RTP / signaling servers
• Experience integrating backend systems with iOS & Android apps
• Strong understanding of real-time data streaming
• Experience with distributed systems & microservices architecture
• Hands-on experience with cloud platforms (AWS / GCP / Azure)
• Familiarity with Kafka / WebSockets / REST APIs

Nice to have:
• Experience with Twilio / Agora / Vonage or similar RTC platforms
• Experience with media servers (Kurento, Janus, FreeSWITCH, Asterisk)
• Knowledge of AI / voice processing / speech analytics
• Background in telecom or communication products

Requirements:
• 6+ years of software development experience, including 5+ years in AI/ML or LLM-focused roles
• Strong Python skills
• Hands-on experience with LibreChat (deployment, customization, integrations) !!!
• Experience with LLMs (OpenAI, Google Gemini, etc.)
• Strong knowledge of RAG architecture, prompt engineering, and agent workflows
• Experience with LangChain, LlamaIndex or similar frameworks
• Experience with Vector DB (pgvector/PostgreSQL) and MongoDB
• Experience with Docker, Kubernetes (GKE), CI/CD
• Experience with Microsoft 365 integrations (Teams, Outlook, SharePoint, Graph API)
• Strong system design and architecture skills
• Good communication skills

It is a New Zealand-based business consultancy and advanced monday.com delivery partner. We help Kiwi businesses streamline their operations through process automation, platform integration, and smart workflow design

We're looking for an experienced integration developer to join our team on an ongoing basis. You'll work directly on client projects — building monday.com integrations, automating workflows, and connecting platforms across our client base. This is a hands-on technical role with real client exposure, so clear communication matters as much as clean code.

What You'll Be Doing:

• Building and maintaining custom monday.com integrations using the monday.com API and SDK
• Developing automation workflows in Make (formerly Integromat) connecting monday.com to third-party platforms
• Writing Python and JavaScript/Node.js scripts to extend platform functionality and handle data transformations
• Implementing robust error handling, logging, and monitoring across integrations
• Collaborating directly with clients to understand their workflow requirements and translate them into technical solutions
• Documenting integrations clearly so clients and the internal team can maintain them
• Troubleshooting and resolving issues in live client environments

Must-Have Skills: !!!

• monday.com API & SDK
• Python
• JavaScript
• Node.js
• Make (Integromat)
• Error handling & logging
• Workflow automation
• REST APIs
• Native English fluency !!!
• Nice to Have
• Zapier
• Webhooks
• Xero API
• HubSpot API
• AWS / Azure
• Git / version control
• monday.com Apps Framework
• Power BI
• Power Automate

What We're Looking For

• Proven experience building monday.com integrations — please include examples or portfolio links in your application
• Strong written and spoken English — you'll be communicating directly with NZ business clients
• Available during NZT business hours for at least part of your working day (overlap for meetings and client calls)
• Reliable, self-directed, and comfortable working asynchronously across a remote team
• Someone who takes ownership — you flag problems early and bring solutions, not just issues

For one of our clients, we are looking for a Senior Database Administrator (On-Premise) (m/f/d).
Candidate Location: Worldwide, max. ±1 hour to CET.

About the Role
This is a hands-on senior on-premise DBA role focusing on the operation, optimization, and further development of critical production database systems. The role requires deep technical expertise and active involvement in daily operations, troubleshooting, and optimization.
?? Cloud environments (Azure, AWS, etc.) are NOT part of this project and are explicitly excluded by the client.
The consultant will work closely with DevOps teams, internal IT providers, and business stakeholders to ensure stability, performance, and security of distributed database environments.

Must-Haves:

• Senior DBA with 5–10+ years of professional experience
• Proven working experience as Senior Database Engineer / Database Administrator in on-premise environments
• Strong hands-on experience with:
• Distributed MS-SQL and NoSQL databases
• Database design, documentation, and implementation
• Monitoring, performance tuning, and optimization
• Disaster recovery, backup, and data integrity
• Excellent knowledge of T-SQL and solid scripting skills
• Experience with monitoring tools such as:
• Foglight, PRTG, ELK Stack, Grafana, Splunk
• Strong analytical and problem-solving mindset
• Business awareness and ability to translate requirements into technical solutions

Nice to have:

• Database containerization experience (Docker, Kubernetes, OpenShift)
• Relevant certifications (e.g. Azure DBA – certification only, no cloud usage)

Responsibilities

• Maintain database systems at a safe operational level with high availability and performance
• Design and implement database solutions aligned with business requirements
• Apply patches, upgrades, and system changes
• Roll out and maintain Always-On concepts for critical databases
• Ensure reliable backup, recovery, and disaster-recovery processes
• Manage database users and harden security
• Monitor systems and resolve issues sustainably
• Analyze deadlocks and optimize query performance
• Implement indexing strategies and performance improvements
• Ensure seamless data synchronization across distributed systems
• Define, document, and maintain database policies and standards
• Provide Level-4 incident support together with 12 DevOps teams
• Train DevOps teams and developers on database best practices
• Review existing implementations and proactively propose enhancements

Project Details
Start: ASAP / within 4 weeks
Duration: Until 31.12.2026, with option for long extension (12+ months)
Location: Remote (99%), 1-2 trips a year to Hamburg (costs covered)!!!
Workload: Full-time (35–40h/week)
Language: English (fluent)
Candidate Location: Worldwide, max. ±1 hour to CET.

Project title: Support implementation efforts for the Agent Data Loop project

Must-haves:

• Golang: Strong proficiency and experience is required as a primary language
• API Development: Extensive experience with REST APIs.
• Databases: Basic knowledge and hands-on experience, for example with PostgreSQL or SAP HANA
• AI & LLMs: General knowledge of Large Language Models (LLMs) and AI Agents.

Nice-to-Haves:

• OpenTelemetry experience
• Performance & Load Testing: Familiarity with testing frameworks, for example Locust

Expertise & Seniority Level:

• Senior-Level Independence: Must be able to work autonomously with minimal onboarding.
• Architectural Alignment: Capable of high-level collaboration on system design and project goals without needing tactical intervention on daily tasks.

Language: English
Location: remote from Poland/EU
Duration: potentially until end of year

AI Systems Full-Stack Engineer ASAP

Location: UK-based !!!
English: B2+
Start: ASAP
Duration: long-term
Engagement: Full/Part-time

We're looking for a Full-Stack Engineer to build scalable, intelligent data applications that combine modern web development, cloud infrastructure, and AI capabilities.

Tech Stack:

• Backend: R (Shiny, Golem, R6), Plumber
• Frontend: Bootstrap 5, HTML5, CSS3, JavaScript
• Data: MariaDB (AWS RDS), S3, SQL
• DevOps: GitHub Actions, Docker, Heroku / DigitalOcean
• AI/ML: LLM APIs (OpenAI, Claude), ellmer (R), Python

What You'll Do:
- Design and develop modular, production-grade applications with interactive dashboards and responsive user interfaces.
- Structure scalable backend systems, implement clean architecture patterns, and ensure maintainability of complex applications.
- Create polished, responsive UI using modern frameworks (Bootstrap, HTML/CSS, JavaScript), going beyond default templates.
- Connect applications to databases and storage systems, optimize queries, and design efficient data pipelines.
- Implement LLM-powered features such as chat interfaces, data assistants, and automated workflows.
- Manage CI/CD pipelines and deploy applications in cloud environments (Heroku, Docker, or similar platforms).
- Maintain clean code practices, documentation, testing, and performance optimization.

Must-have:
* Strong full-stack development experience
* Solid backend architecture skills (modular design, state management)
* Experience with modern frontend development (responsive UI, component-based approach)
* Advanced SQL and database design knowledge
* Experience with CI/CD pipelines (e.g., GitHub Actions)
* Cloud deployment experience (Heroku, Docker, or similar)
* Hands-on experience integrating LLMs / AI features into applications

Nice-to-have:
* Experience with data-heavy or analytics platforms
* Knowledge of AI systems (RAG, agents, workflow automation)
* Familiarity with AWS ecosystem (S3, RDS, IAM)
* Python for AI/ML workflows
* Understanding of web security best practices

Location: any
Start: ASAP
Duration: long-term (around 6 months)
Engagement: Full-time
English: B2+

Key Responsibilities 
We are looking for someone who can contribute further to our Agentic AI platform for construction, need an LLM engineer who understands the following:
 

• Design and implement deterministic workflows that ensure consistent, reliable outputs from LLMs
• Solve fundamental challenges like making LLMs perform accurate mathematical operations (e.g., ensuring 1+1=2 consistently)
• Build robust evaluation frameworks to measure and guarantee deterministic behavior
• Implement comprehensive guardrails leveraging structured output and Pydantic models for input/output validation
• Understanding of training dynamics, loss functions, and optimization strategies
• Experience with parameter-efficient fine-tuning methods (LoRA, QLoRA, etc.)
• Proficient in implementing and managing tool calling mechanisms
• Deep understanding of Model Context Protocol (MCP) architecture and implementation
• Experience in building and deploying LLM-powered applications using FastAPI/Flask and Streamlit for front-end interfaces, solid understanding of REST principles, HTTP Methods, websockets and API lifecycle management;
• Experience with SQL, NoSQL (PostgreSQL, MySQL, MongoDB, Redis) and vector databases (Pinecone, Weaviate, pgvector) for structured data storage and semantic search

We have a fully built real estate & rental management platform (React + TypeScript + Supabase, 200+ DB tables, live in production). We need an AI engineer to build and integrate the AI layer — the "brain" of the platform.

WHAT YOU'LL BUILD:
1. 3-Layer AI Architecture:
• Platform Brain — central AI that oversees all data across multiple companies
• 7 Department AI Agents — each with its own expertise (Investment, Sales, Finance, HR, Marketing, Operations, Leads), unique system prompts, and scoped database access
• Employee Personal AI — learns each employee's communication style over time, auto-replies to messages, drafts emails in their voice, gets smarter with every interaction

2. AI Features:
• Auto-fill property listings from just an address (AI generates descriptions, neighborhood info, nearby transport, amenities)
• AI Chat widget for website visitors (multilingual: EN/ES/HE)
• AI Meeting system — summarizes video meetings, extracts action items, runs "AI Agent Meetings" where all 7 agents discuss strategy using real company data
• AI Competitor tracking — auto-analyzes competitor websites and social media
• Content generation for marketing (text, social posts, suggestions)

3. API Integrations:
• Claude API (Anthropic) — primary LLM
• ElevenLabs — voice generation
• Vector embeddings with pgvector (built into our Supabase)

TECH STACK (already built, you integrate AI into it):
• Frontend: React + TypeScript + Tailwind
• Backend: Supabase (PostgreSQL + Edge Functions + Auth + Realtime)
• Deployment: Lovable Cloud
• Code: GitHub

REQUIREMENTS:
• 3+ years with LLM APIs (Claude and/or OpenAI) in production !!!
• Experience building multi-agent AI systems !!!
• Strong TypeScript/Node.js
• Supabase or PostgreSQL experience
• Vector embeddings & RAG (Retrieval Augmented Generation)
• Prompt engineering expertise

We are looking for a hybrid profile combining Data Engineering and DevOps experience

The role is until April 2027 with potential extension.

The role is full time full remote for a Major international client.

To help you we need ideally a profile of Senior Data Engineer with Senior experience with Snowflake ETL/ELT pipeline,  data pipelines in production,  data warehouse,  data workflows,  Data Platform,  DevOps, cloud infrastructure, CI/CD AWS,  GIT, modern development ,  with Terraform or Docker

Data Engineer Snowflake with relevant experience with Data Platform
We are looking for a hybrid profile combining Data Engineering and DevOps experience.
Looking for someone with Senior capacity, at least 4 years of exp.as data engineer, someone who can thrive as part of a team, but can work independently.

Nothing specified as years of experience rather than 4+ general one. Still we are looking for people with senior capacity.
Only candidates with truly relevant and strong experience will be considered in the process. This will be assessed by our team
 

• Must to have relevant experience wih Snowflake
• Must to have relevant experience with ETL/ELT pipeline
• Must to have relevant experience with data pipelines in production
• Must to have relevant experience with data warehouse
• Must to have relevant experience with data workflows
• Must to have relevant experience with Data Platform
• Must to have relevant experience with DevOps
• Must to have relevant experience with cloud infrastructure
• Must to have relevant experience with Terraform or Docker
• Must to have relevant experience with CI/CD
• Must to have relevant experience with AWS
• Must to have relevant experience with GIT
• Must to have relevant experience with modern development workflows

You’ll be working on event-driven, distributed, and scalable systems in Python, building large-scale data and service pipelines on AWS that support project’s content enrichment and metadata systems. This is a long-term remote opportunity with a supportive international team and strong ownership from day one.
This is a long-term, fully remote opportunity with a supportive international team and plenty of room for ownership.

Client is an American ebook and audiobook subscription service that includes more than one million titles. They began as a site to host and share documents and has grown into a global digital library with over 1.5 million subscribers in nearly every country worldwide.
The team focuses on building scalable metadata pipelines that utilize traditional tools, in-house ML models, and LLMs. In this role, you’ll design and optimize large-scale data and service pipelines running on AWS, supporting project’s content enrichment and metadata systems. You’ll work closely with cross-functional teams to design reliable backend services that integrate machine learning models and LLM-based components when needed. This role offers the opportunity to work on cutting-edge generative AI and metadata enrichment problems at a truly global scale.

Platform Tech Stack:
Python 3.10.x, PySpark, Airflow, pytest, Pandas, AWS, Delta Lake, MySQL (Aurora), Databricks, Terraform, Datadog, AWS Lambda, ECS, SQS, SNS, ElastiCache, CloudWatch.

Responsibilities:
● Provide technical leadership, mentorship, and guidance to engineers across the organization, driving secure coding best practices
● Lead the design, implementation, and scaling of event-driven, distributed systems to extract, enrich, and process metadata from large-scale document and media datasets
● Partner with Data Science, Infrastructure, ML Engineering, and Product teams to architect and deliver robust systems that balance scalability, high performance, and rapid iteration
● Contribute to the team’s engineering strategy, identifying gaps, proposing new initiatives, and improving existing frameworks
● Build and maintain scalable APIs and backend services for high-throughput content processing
● Leverage AWS services such as ECS, Lambda, SQS, ElastiCache, and CloudWatch to design and deploy resilient, high-performance systems
● Optimize and refactor existing backend systems for scalability, reliability, and performance
● Ensure system health and data integrity through monitoring, observability, and automated testing

Required skills:
- 7+ years of experience as a professional software engineer
- Strong proficiency in Python
- Proven ability to lead the design and delivery of complex software systems with minimal supervision
- Expertise in designing and architecting large-scale event-driven and distributed systems
- Strong cloud expertise with AWS services such as ECS, Lambda, SQS, SNS, and CloudWatch
- Familiarity with data processing frameworks such as Spark and Databricks
- Experience with infrastructure-as-code tools like Terraform
- Solid understanding of system performance, profiling, and optimization
- Experience leading technical projects and mentoring engineers
- Experience building and maintaining data-intensive backend systems or pipelines
- Upper-Intermediate English or higher

Nice to Have:
● Experience with Scala
● Familiarity with Ruby
● Bachelor’s degree in Computer Science or equivalent professional experience
● Experience with workflow orchestration tools such as Airflow
● Experience integrating ML or LLM-based models into production systems


Working Conditions:
— Work schedule: EST working hours !!!!
— Fully Remote
— Engagement: Long-term
— Full-time workload
— 2-week sprints with kickoff on Monday evenings and demos on Friday evenings