Kozak Agency

About the Project
We are looking for an experienced Senior Product Analytics Lead to join a fast-growing international fintech company developing digital payment and customer experience solutions for the hospitality industry.
The company already has a Product Analytics function, a Data Engineering team, and an existing experimentation platform. The next step is to scale experimentation beyond Product into Operations, Sales, and other business functions.
The key objective is to establish a scalable experimentation framework that enables teams to independently design, execute, and evaluate 50+ A/B tests per month.

Key Responsibilities

• Own and scale the company’s experimentation framework across Product, Operations, Sales, and other departments.
• Improve and configure the existing A/B testing infrastructure (currently GrowthBook), evaluate alternatives, and implement improvements where needed.
• Establish standards for experiment design, sample sizing, statistical significance, success metrics, and guardrails.
• Apply advanced statistical methods, including power analysis, variance reduction, and sequential testing.
• Enable experimentation across web and mobile applications.
• Develop experimentation playbooks, templates, documentation, and best practices.
• Train Product Managers, Operations Leads, and other stakeholders to design and run experiments independently.
• Review experiment quality, interpret results, and translate findings into actionable business recommendations.
• Collaborate with Product, BI, Data Engineering, and leadership teams to improve data-driven decision-making.
• Contribute to analytics tooling and data modeling decisions where relevant.

Requirements

• 5+ years of experience in Product Analytics, Experimentation, Data Science, or a related field.
• Proven hands-on experience building or significantly scaling an experimentation program in a data-driven organization.
• Strong knowledge of A/B testing methodology, experiment design, and statistical analysis.
• Practical experience with experimentation platforms such as GrowthBook, Statsig, Optimizely, or similar tools.
• Experience designing and implementing scalable experimentation processes, not just analyzing test results.
• Ability to independently configure experimentation tools and improve existing infrastructure.
• Strong SQL skills and experience working with product analytics data.
• Experience collaborating with Product, Engineering, Data, and business teams.
• Proven ability to introduce new processes, train stakeholders, and drive adoption across departments.
• Strong communication skills and ability to work independently with senior stakeholders.
• Upper-intermediate or higher English proficiency.

Nice to Have

• Experience in large, data-driven companies or established experimentation environments (e.g., Uber, Booking, Delivery Hero, Amazon, Meta).
• Experience with Data Modeling, dimensional modeling, SCDs, event schemas, and data governance.
• Experience with dbt, BigQuery, ClickHouse, or other modern analytical data platforms.
• Familiarity with Mixpanel, Amplitude, Tableau, or similar analytics tools.
• Experience setting up experimentation for mobile applications.
• Experience in fintech, payments, e-commerce, or high-traffic consumer products.
• Experience leading or mentoring analytics teams.
• Familiarity with AI-powered analytics tools and workflows.
• Current Environment

Experimentation: GrowthBook (existing setup, open to improvements or alternative platforms)
Data Warehouse: BigQuery
BI: Tableau (planned transition to other tooling)
AI: Claude with MCP integration
Communication: Slack, Google Workspace
The selected specialist will have the opportunity to influence future tooling decisions.

A dynamic international trading company is looking for an experienced C++ Developer for development of an in-house ultra-low-latency trading platform. The platform has been developed internally and continues to evolve with new modules, exchange connectivity, and trading capabilities. The role involves contributing to the ongoing development, performance optimization, and expansion of this system.

Responsibilities
• Develop and enhance components of a high-performance, ultra-low-latency trading platform
• Design & implement ultra-low-latency trading modules from scratch within a Linux environment. • Optimize existing codebases for microsecond-level performance and deterministic execution.
• Work with high-throughput market data and order routing systems
• Implement and maintain exchange connectivity and data feed handlers
• Contribute to improving system architecture, performance, and scalability
• Collaborate with traders and engineers to deliver robust trading infrastructure • Develop client-server data exchange systems using raw TCP/UDP and multicast protocols.
• Interface with global exchanges using FIX and SBE binary protocols.

Required Experience
• 6+ years professional C++ development experience, with at least 3 years with high-performance / low-latency systems
• Strong knowledge of modern C++ (C++17/20 preferred) and STL
• Deep understanding of Linux internals, multithreading, and memory management
• Experience with multithreaded and concurrent programming
• Proficiency in TCP/IP sockets and network protocol design programming
• Understanding of client-server architecture and distributed systems
• Experience writing highly optimized, performance-critical code
• Strong debugging and problem-solving skills

Preferred Experience
• Experience with FIX protocol (text-based or binary FIX/SBE)
• Experience with multicast networking & high-performance message processing systems
• Experience in financial markets or electronic trading systems
• Familiarity with market data feeds and exchange connectivity
• Knowledge of performance profiling and latency optimization

Key requirements:

• 3+ years of commercial Full-Stack development experience with Angular, TypeScript, Tailwind CSS
• Strong Python backend skills, SQL, REST APIs and third-party integrations
• Experience with testing and CI/CD
• Daily use of AI coding tools (Claude Code, Cursor, Copilot, etc.)
• Experience working in R&D, DefenceTech, or MedTech environments.

English B2+
Nice to have: Azure, Docker, CRM/ERP integrations, AI Agents

Remote|Full-time|CET hours

Location: Poland (Kraków preferred)
Work format: Full-time
Project: International fintech payments platform combining traditional payment systems with crypto infrastructure.

Responsibilities:

• Build and scale a modern fintech payments platform.
• Develop real-time processing, settlement, reconciliation, and wallet services.
• Provide technical leadership for teams of 5–15 engineers.
• Drive architectural decisions, conduct code reviews, and mentor engineers.
• Stay hands-on with daily coding and end-to-end technical ownership.

Requirements:

• 8+ years of production experience with TypeScript/JavaScript (frontend & backend).
• Strong expertise in React, Node.js, and GraphQL/Apollo.
• Hands-on experience with AWS Serverless architecture.
• Strong knowledge of DynamoDB/NoSQL and PostgreSQL.
• Proven experience leading technical teams of 5–15 engineers.
• Experience with AI-assisted development tools, including 1+ year with Anthropic Claude.
• Tech stack: TypeScript, React 19, Node.js, GraphQL/Apollo, AWS, DynamoDB, PostgreSQL, Playwright, CDK.

Nice to have:

• Experience in fintech/payments, settlement systems, PCI compliance, ledger systems, or fee models.

Important: Candidates must be physically located in Poland. Kraków is preferred, but other Polish cities are also considered !!!!

We are looking for an experienced Mobile App Developer to support a project in the financial IT sector, focusing on implementing offline capabilities in an existing mobile application.

Start Date: ASAP
Duration: 6 months (extension possible)
Workload: 80–100%
Location: Remote

Language: German preferred; English-speaking candidates also considered
 

Responsibilities
Gather and analyze business and technical requirements.

Familiarize yourself with technical parameters, particularly security-related requirements.

Align technical requirements with the current versions of MobileIron and iOS 27.

Estimate the effort required for development and implementation.

Implement necessary adjustments within the available project budget.

Must-Have Requirements

Experience in mobile application development.

Knowledge of MobileIron and MDM environments.

Experience with security-related requirements.

Knowledge of EWS and Kerberos.

Nice-to-Have Requirements

Experience in the financial IT sector.

Experience with offline scenarios.

Knowledge of Exchange and VPN access.

Критично досвід з:

MobileIron / Ivanti MDM

MDM environments (Microsoft Intune, Samsung Knox, -Workspace ONE or similar)

EWS (Exchange Web Services)

Kerberos authentication

Microsoft Exchange and VPN integration

Enterprise mobile security requirements

Offline functionality and data synchronization

Project Description:
Technical Project Description
Configure and extend Dynamics 365 Customer Service to manage praise, feedback, complaints and treatment-error cases. The scope includes case configuration, statuses, SLA tracking, queues, routing, email intake, reminders, escalations, dashboards, permissions and Power Automate workflows. Integration with the client’s existing expert software may also be required.

Project Architecture
Dynamics 365 Customer Service based on the standard Case entity in Dataverse. Native queues, SLAs, email templates, views and dashboards will be combined with Power Automate flows. Custom code or API integration should only be used where standard configuration and low-code automation cannot meet the agreed requirements.

Tech Stack:

• Dynamics 365 Customer Service
• Microsoft Dataverse
• Power Automate
• Dynamics 365 App for Outlook
• Exchange / shared mailboxes
• Entra ID
• Dataverse Web API
• Power Platform solutions and environment management

Must-Have Technologies!!!

• Dynamics 365 Customer Service
• Microsoft Dataverse
• Power Automate
• Case management, queues and routing
• SLA and entitlement configuration
• Dynamics security roles and access model
• Outlook and Exchange integration
• Power Platform solution deployment

Responsibilities:

• Review the requirements and fit-gap assessment.
• Inspect the client’s Dynamics tenant and existing configuration.
• Clarify process, licensing, security and integration dependencies.
• Design the Dynamics 365 solution and provide an effort estimate.
• Configure cases, forms, fields, queues, SLAs, views and dashboards.
• Implement Power Automate reminders, notifications and escalations.
• Configure email intake and Outlook workflows.
• Support integration with the existing expert software.
• Prepare tests, deployment documentation and handover materials.

Nice to Have:

• Dataverse Web API and external system integrations
• Microsoft Entra ID
• Power Pages
• Dynamics telephony or Contact Center integrations
• Copilot Studio
• Experience with GDPR-sensitive or healthcare-related workflows

Workload
Project-based, initially part-time for discovery and solution design, followed by implementation. Final workload will be defined after tenant inspection and scope validation.

The specialist should prioritise standard Dynamics functionality and supported low-code configuration. The current documents are assessment materials, not an approved final specification. Strong English communication and the ability to work directly with business stakeholders are required.

Start: immediately
Location: Remote, EU, Ukraine
Workload: full-time, 40 h/week
Start: ASAP
Language: English min. B2
Experience: 7 Years+
Contract: flexible; 6 months fixed, option to convert to permanent
Rate: open to proposals

CONTEXT
An agentic enterprise AI platform, currently running in the cloud (per customer).
They are building an on-prem version for customer / colocation data centers.
This is a founding engineer role for the on-prem product: the candidate builds the tooling so customers can install, upgrade, back up, restore and troubleshoot the platform without Kubernetes knowledge.

MUST-HAVE

• Kubernetes in production (strong, hands-on)
• Writing and maintaining Kubernetes operators (CRDs, controllers)
• Building a CLI / lifecycle tooling: install, configure, upgrade, scale, backup, restore
• Distributed, microservice-based systems
• Platform engineering / developer tooling / internal infra products
• Load, stress and resilience testing, performance baselines and sizing
• Operational security, secure deployments, incident response
• Strong in at least 2 programming languages (Go is a natural fit for operators/CLI)
• Product mindset, ownership, good communication (English, German is a plus)
• Lead-level seniority: able to shape technical decisions

NICE-TO-HAVE

• SUSE Rancher, k3s
• On-prem deployments in customer environments
• Azure
• .NET 10, ASP.NET Core, Aspire
• Self-hosted / customer-operated products, installers, appliances
• Security-sensitive or regulated environments
• Functional programming / formal verification

CANDIDATE PROFILE
Senior/Lead, ideally 7+ years, with clear on-prem Kubernetes experience
Available to start immediately

Location: Barcelona or Remote (EU Only) !!!
Employment: Full-time, B2B
Start: January 1, 2027!!!!!
Duration: 6 months
Work format: Fully Remote / Barcelona

About the Project
We are looking for a Senior Android Developer to join an international project focused on developing and maintaining modern Android applications using Kotlin and Jetpack Compose.

 Key Responsibilities:

• Develop and maintain Android applications using Kotlin and Jetpack Compose.
• Build scalable UI components and implement clean architecture.
• Integrate REST APIs, Firebase, AWS, and third-party services.
• Optimize application performance and troubleshoot production issues.
• Write unit and integration tests, conduct code reviews.
• Collaborate with cross-functional teams in an Agile environment.

Technical Requirements:

• Strong experience with Kotlin & Jetpack Compose.
• Koin DI & Room Database.
• Firebase & AWS.
• Contentful CMS & PhraseApp.
• Instabug for bug reporting.
• Splunk & New Relic for monitoring.
• REST API integration.
• GitHub, Jira & Confluence.
• Unit & integration testing.

Soft Skills:

• Strong English communication skills.
• Excellent problem-solving abilities.
• Experience working in Agile teams.

Duration: long-term
Start: ASAP
Location: EU, Ukraine
Time zone: UK
 

We are looking for a strong Senior Platform Engineer with relevant security experience to urgently replace a team member who has left the project.

The project is confidential, so we cannot share requirements or technical details. The tech stack is not the main criterion for the client. They need a broad, experienced engineer who is comfortable with a wide range of technologies, is trustworthy, and will stay on the project long-term.

Engagement: Full-time
Location: EU (mandatory)
English: Upper-Intermediate (B2)
Availability: Full-time
 

About the Role

We are looking for an experienced Back End Engineer to join our team and work on a project using Python and FastAPI.

We need an engineer who can independently manage the entire backend development lifecycle — from understanding requirements and designing solutions to implementation, testing, deployment, and production support.
 

Requirements

• Commercial experience with Python and FastAPI in production.
• Hands-on experience with asyncio, Dependency Injection, and background tasks.
• Strong knowledge of PostgreSQL, including transactions, locking, indexes, and safe migrations.
• Experience implementing authentication and authorization using OAuth2/OIDC and JWT.
• Understanding of stateless services and backend architecture principles.
• Production experience with AWS or Azure.
• Daily use of AI-powered development tools such as GitHub Copilot, Cursor, Claude, or similar.
• Ability to work autonomously, translate requirements into technical solutions, make engineering decisions, write tests, and deliver features to production.
   

Nice to Have

• Experience with Redis.
• Knowledge of Hasura and GraphQL.
   

Important Details

• Candidates must be physically located in an EU country.
• Full-time availability is required.
• English level: Upper-Intermediate (B2) or higher.

Engagement: Full-time
Location: EU (mandatory)
English: Upper-Intermediate (B2)
Availability: Full-time
 

About the Role

We are looking for an experienced Full Stack Engineer to join our team and work on a project using a modern technology stack.

We are looking for an engineer who can independently manage the entire development lifecycle — from understanding requirements and designing solutions to testing, deployment, and production support.
 

Requirements

• Commercial experience with Python  in production.
• Hands-on experience with asyncio, Dependency Injection, and background tasks.
• Strong knowledge of PostgreSQL, including transactions, locking, indexes, and safe migrations.
• Experience implementing authentication and authorization using OAuth2/OIDC and JWT.
• Understanding of stateless services and backend architecture principles.
• Production experience with AWS or Azure.
• Daily use of AI-powered development tools such as GitHub Copilot, Cursor, Claude, or similar.
• Ability to work autonomously, translate requirements into technical solutions, make engineering decisions, write tests, and deliver features to production.
   

Additional Requirements for the Full Stack Role

• Confident Middle-level experience with React.
• Commercial experience with TypeScript.
• Hands-on experience with Next.js.
   

Nice to Have

• Experience with Redis.
• Knowledge of Hasura and GraphQL.
   

Important Details

• Candidates must be physically located in an EU country.
• Full-time availability is required.
• English level: Upper-Intermediate (B2) or higher.

Engagement: Contract, 40 h/week (full-time)
Location: Fully remote; candidates must be based in the EU or UK
Start date: Mid-November 2026
Duration: 6 months initially, extension likely
English: B2-C1
Interview process: 3 rounds
 

About Us
We’re a fast-growing semiconductor and hardware engineering company building the core architecture for next-generation computing. We believe great engineering can happen anywhere, so we’re growing a distributed team. We’re looking for a Senior RTL Design Engineer to join us remotely on a contract basis.
If you live in the European Union or the United Kingdom and want to take high-performance, low-power digital designs from micro-architecture all the way to silicon, we’d like to hear from you.
 

The Role
You’ll own the micro-architecture and write clean, maintainable RTL for advanced digital integrated circuits. You’ll work closely with the architecture, verification, synthesis, and physical design teams so that every design moves smoothly from code to tape-out.
 

What You’ll Do

Micro-architecture and design: turn architecture specifications into robust, scalable, high-performance micro-architectures and RTL (Verilog, SystemVerilog, or VHDL).
Work with verification: debug RTL issues together with the verification team, help shape test environments, and make sure the design reaches full coverage.
IP integration: handle integration at block and subsystem level, and keep releases and documentation clean and up to date.

What We’re Looking For

Experience: 5+ years in digital front-end design, RTL coding, and complex IP/SoC integration.

Technical skills:
Expert-level Verilog, SystemVerilog, or VHDL.
Deep knowledge of synchronous design, clock domain crossing (CDC), and low-power design techniques.
Hands-on experience with industry-standard EDA tools (Synopsys, Cadence, or Siemens EDA) for simulation, linting, synthesis, and static timing analysis (STA).

Architecture knowledge: a strong grasp of computer architecture, such as high-speed datapaths, bus protocols (AMBA/AXI), memory controllers or custom compute blocks.

Education: a Bachelor’s or Master’s degree in Electrical Engineering, Computer Engineering, or a related STEM field.
Location: you must live in the EU or UK and have the right to work there. The role is fully remote, but we need you to be based in these regions for tax and compliance reasons.
Soft skills: you work well on your own, solve problems proactively, and explain technical ideas clearly in English.

Workload: full-time
Duration: long-term till 30th of June 2027, with possible extension
Start: asap
Location: any
English: B2

We are looking for an experienced SAP ABAP Senior Developer with full-time availability and an immediate start to join the existing client's team.
Client Company Domain: Retail / Food Retail / Supermarket & Grocery Retail

Key Responsibilities – SAP ABAP Developer:

• Develop, enhance, and maintain SAP ABAP applications based on business requirements.
• Analyze functional specifications and translate them into technical solutions.
• Develop and support reports, interfaces, enhancements, forms, and other custom SAP developments.
• Troubleshoot and resolve technical issues, including debugging and performance optimization.
• Collaborate with functional consultants and other developers to deliver SAP enhancements and integrations.
• Perform unit testing and provide technical documentation.

Workload: full-time, 100% remote
 Start: ASAP
 Duration: long-term
 Format: staff augmentation
 English: strong communication skills required
 

Project Overview
Fintech project. The client needs a strong Senior Data Scientist with hands-on LLM experience who can own the technical stack end to end, work with leadership on data science strategy, and explain technical decisions clearly to non-technical stakeholders.
 

What You’ll Do
Work with leadership to shape and implement the company’s data science strategy and find opportunities to use data for business value
Own the full technical stack needed for development and deployment
Develop and maintain scalable ML models and systems
Keep data management and engineering practices solid, with efficient data pipelines
Gather requirements from cross-functional teams and provide insights
Explain complex technical concepts to non-technical stakeholders
 

Must-Have Requirements
7+ years of total experience, including participating in and/or leading complex projects
Master’s or PhD in Data Science, Computer Science, Statistics or a related field, or equivalent knowledge and experience
Hands-on expertise in modern language models and ML frameworks
Practical experience with different LLMs of various sizes and from different providers
Optimizing LLM-based pipelines for performance and cost efficiency
Building agents that work across different tools and LLMs
LLM-based data capture and extraction
Experience with modern LLM-supporting frameworks and tools
Modern LLM prompting techniques
Building evaluation pipelines using data-driven approaches
Managing feedback and training pipelines, and fine-tuning models
Python, R, or another strongly typed language
Cloud platforms (AWS, GCP or Azure) and deployment processes
Excellent communication: must confidently explain ideas and technical decisions
 

Nice to Have
Big data technologies (Spark, Hadoop, data warehouse / data lake technologies)
Data architecture and database management background
Data management and engineering tools
Knowledge of accounting and bookkeeping
Commitment to ethical AI practices and data governance
 

Key Competencies
 Problem-solving and strategic thinking, ability to innovate and drive process improvements, collaboration.
 

CV must be reworked to match the requirements above