Kozak Agency

Department: e-Health & AI
Reporting to: Head of AI & Data
Working hours: Full-time, 9:00 AM - 6:00 PM CET

Project Overview
We are looking for a Senior NLP & Python Developer to join a product team building a Clinical Trial Management System (CTMS) for research sites.
The platform helps clinical research organizations activate and manage studies efficiently while ensuring full regulatory compliance. A major component of the system is an AI-powered protocol intelligence engine that analyzes complex clinical trial protocols (100–400+ page medical documents) and converts them into structured workflows.

The AI system extracts and processes:
* Schedule of Assessments (SoA)
* Visit structures and timelines
* Inclusion / Exclusion criteria
* Investigational product requirements
* Regulatory and operational tasks

This is a technically demanding environment requiring:
* RAG pipeline architecture
* medical document parsing
* structured data modeling
* deterministic AI output design
* traceability and auditability
* validation-ready engineering practices aligned with regulated environments

Tech Stack
Backend / Infrastructure
* Python 3.x
* FastAPI
* SQLModel / SQLAlchemy
* PostgreSQL
* pgvector
* Docker / Docker Compose
* Celery
* Redis
* RabbitMQ

AI / NLP
* LangChain
* LangGraph
* RAG pipelines
* embeddings
* vector search
* LLM orchestration
* NER models
* VLMs
* document extraction pipelines

Engineering / Quality
* CI/CD
* structured logging
* observability / monitoring
* automated testing
* secure coding practices

Team Structure
Cross-functional product team including:
* Senior ML/Python Engineer
* ML Architect
* Frontend Engineer
* QA Engineer
* Business Analyst
* Project Manager

Responsibilities
AI / NLP Architecture
* Design and optimize RAG-based pipelines for medical protocol parsing
* Refactor LangChain workflows for scalability, modularity, and cost efficiency
* Implement dynamic model orchestration based on task complexity
* Improve explainability and traceability of AI outputs
* Build deterministic transformation layers from extracted AI output to executable workflows
* Optimize vector search performance
* Integrate external regulatory and medical knowledge sources
* Develop document/content classification pipelines

Backend & Data Architecture
* Design scalable PostgreSQL schemas
* Model complex clinical entities:
  * Studies
  * Visits
  * SoA
  * Eligibility criteria
  * Regulatory tasks
* Ensure audit trail capabilities
* Improve database performance and transactional consistency

System Hardening & Validation
* Implement monitoring and structured logging for AI pipelines
* Improve reproducibility and explainability
* Expand automated testing coverage
* Support validation readiness for regulated environments
* Enforce secure engineering practices

DevOps & Scalability
* Maintain Docker-based deployments
* Improve CI/CD workflows
* Support monitoring and error tracking
* Ensure scalability for multi-site / multi-study usage

Required Experience
Backend / Architecture
* 5+ years with Python
* Strong FastAPI experience
* Deep SQLAlchemy expertise
* Strong PostgreSQL knowledge (schema design, indexing, migrations, tuning)
* Experience with Docker-based deployments
* Experience with Celery / Redis / RabbitMQ
* Strong system architecture skills
* Experience with document extraction systems

NLP / AI
* Hands-on experience with LangChain
* Production RAG implementation experience
* Experience with vector databases (preferably pgvector)
* Knowledge of embeddings and model orchestration
* Prompt engineering experience
* Experience designing deterministic AI systems

Domain Experience
Experience in regulated industries is strongly preferred:
* healthcare
* life sciences
* fintech
* other compliance-heavy environments

Nice to Have
* GxP / validation-ready AI systems experience
* experience with pre-commit / Ruff / Poetry
* large-scale system re-architecture experience

Ideal Profile
Looking for someone who:
* thinks architecturally, not just feature-by-feature
* can balance AI innovation with production reliability
* is comfortable in early-stage product environments
* communicates well across engineering, product, and QA teams
* has real production AI/NLP ownership, not only experimentation or prototypes



Start date: beginning of June
Duration: 6 months
Working hours: 9 AM – 6 PM CET
Payment terms: 40 days

We’re looking for a Full-Stack Engineer (PHP/Laravel, React) for a short-term project lasting from 2 weeks to 3 months. It will start as a full-time engagement and then transition to part-time.

Details:

• Senior Full-Stack Engineer (PHP/Laravel, React) with 8 years of experience.
• Strong proficiency in English (Upper-intermediate level or Advanced).
• Full-time
• Fully remote
• Location: Ukraine or Europe.
• Start: ASAP!

Experience / Skills:

• At least a Bachelor's with a background in tech or equivalent, based on work experience
• 8 years of work experience with the Laravel and React frameworks
• Experience building applications with JavaScript/Typescript, PHP, HTML5, CSS, and MySQL 8
• Passionate about usability, user experience, beauty, and elegance of UI's
• Eager to learn, discuss, and share knowledge with the rest of the teams
• Nice to have: knowledge of Kubernetes, Docker, and other tools used in DevOps
• Absolute fan of TDD and CI/CD pipelines
• Strong track record of leading technical projects and coordinating teams of 3+ engineers
• Experience mentoring and supporting the professional growth of fellow engineers
• Background in product-based companies with multiple products and engineering teams
• Proven track record of driving engineering initiatives that impacted other teams or the wider organization
• Excellent presentation and communication skills, with the ability to clearly explain technical concepts and join customer calls when needed

Required Skills
Experience building RAG pipelines and agentic systems
Strong understanding of LLM orchestration frameworks:
LangChain, LangGraph, Langfuse for example
Strong backend engineering experience with Python
Hands‑on experience building APIs/services with FastAPI
Experience integrating with MCP tools, internal APIs, and enterprise systems
Experience building Agent Factories, agent workflows, or multi-agent systems
Solid understanding of distributed systems and event-driven architectures
Experience deploying and operating services on AWS (EKS, S3, Lambda, IAM, networking)
Familiarity with GitLab CI for automated testing and deployments

Desired Skills
expertise with OpenSearch:
Index design, ingestion pipelines, analyzers, relevance tuning
Vector search, hybrid search, embeddings integration
Performance tuning and scaling clusters
Knowledge of embeddings generation and vector database best practices
Experience with OpenSearch plugins, custom scoring, or ingestion frameworks
Familiarity with Kubernetes
Experience with observability stacks (OpenTelemetry, Prometheus, Grafana, Langfuse)
Understanding of enterprise security, RBAC, and data governance
Prior experience building internal knowledge platforms or developer tools

Start ASAP
Duration 6 MM
Location: EU
English language

Qualifications:
— 8+ years of professional backend development experience using modern languages (Go, Python, or JavaScript/TypeScript).
— 4+ years of hands-on Blockchain development experience.
— Vast experience designing and scaling high-scale distributed systems.
— Deep expertise in microservices architecture and robust API design.
— Strong knowledge of consensus mechanisms, cryptographic primitives, and distributed ledger principles.
— Hands-on experience with Docker, Kubernetes, and Helm.
— Proven track record of building blockchain solutions specifically for enterprise or institutional use cases.

* Location: Remote (based in Poland).
* Time Zone: CET / European time zones.
* Engagement: Full-time (40 hours per week) with a long-term commitment (minimum 1 year).
* English: Upper-intermediate

Project: A production-grade platform for deploying enterprise AI-powered voice and chat agents at scale. The system features real-time voice bots handling inbound/outbound calls, multi-agent orchestration, and telephony integration with sub-100ms latency.
- Architect and manage real-time voice pipelines processing concurrent calls.
- Implement multi-agent orchestration, state machines, and RAG pipelines.
- Build and scale multi-tenant distributed systems using asynchronous processing.
- Integrate telephony protocols (SIP/PBX) and real-time streaming technologies.
- Own the end-to-end system lifecycle from infrastructure and databases to monitoring.

Requirements:
- 10+ years of professional software engineering experience.
- Deep expertise in Python and asynchronous frameworks (asyncio).
- Solid knowledge of relational databases, vector databases, Redis, and message queues.
- Extensive experience in designing and scaling distributed systems and multi-tenant SaaS architectures.
- Hands-on experience with LLM orchestration, agent frameworks, and NLP.
- Experience with real-time audio/video, telephony/VoIP, and deploying self-hosted STT/TTS models.
- Proficiency with container orchestration, cloud storage, monitoring, and tracing tools.

Nice to have:
- Advanced expertise in WebRTC and real-time audio systems.
- Deep knowledge of PBX/SIP integrations.
- Experience with speech model optimization.
- Prior experience working in startup environments.

Full-time, 10-12 months, start in 3-4 weeks

Project Description:
Our client is building data- and AI-driven solutions in a cloud-first environment, with a strong focus on GCP, BigQuery, and large-scale data workflows. The current work is centered around exploring and defining new solution directions, especially in voice-related use cases, where architecture decisions must balance feasibility, scalability, and production readiness.
The environment is highly collaborative and cross-functional, bringing together technical leadership, data scientists, and engineering teams to shape complex solutions from early discovery through implementation.

We are hiring a Lead Data Engineer to help define and shape solution architecture for new data- and AI-driven initiatives.
This is an architecture-focused role working on GCP-based systems, big data modeling, and agentic / LLM-oriented solution design, with a strong emphasis on turning ambiguous requirements into clear technical options.
You will work on early-stage solution design, feasibility analysis, production architecture planning, and proof-of-concept preparation. The role is especially relevant for candidates with experience in voice data, call-agent systems, or similar real-time / unstructured data environments.

Responsibilities:

• Evaluate technical feasibility of proposed voice-agentic systems
• Design production-grade solution approaches on GCP, especially around BigQuery
• Work with large, unstructured datasets and define storage / transformation strategies
• Support solution design involving LLMs and agentic workflows
• Prepare architecture documentation and technical recommendations
• Help shape proof-of-concept direction and technical scope
• Collaborate closely with technical leadership, data scientists, and engineering teams
  
  
  Required skills:
  Tech Stack:
• Python
• GCP
• BigQuery
• SQL / data modeling
• Large-scale data systems
• LLM / agentic solution design
• Streaming systems (nice to have)
• Voice / call-agent environments (strong plus)

What We’re Looking For

• Strong experience with GCP and cloud-native architecture;
• Strong Python background;
• Deep understanding of big data, data modeling, and analytical storage systems;
• Experience designing scalable, production-oriented architectures;
• Ability to operate in ambiguous environments and translate ideas into solution options;
• Strong communication and documentation skills;
• Ability to explain trade-offs clearly and collaborate across technical streams.

Interview process:

• EnglishCheck
• Internal Tech Interview
• Interview with the client

Nice to Have:

• Experience with LLM / agentic system design
• Experience with voice, speech, or call-agent platforms
• Experience with streaming architectures
• Experience working closely with data scientists on early-stage solution design

We are looking for a Senior DevSecOps with strong Azure background to join a product team working on a high-load AI-powered application.

Key areas of focus:
Azure infrastructure and security (Entra ID, Managed Identity, networking)
Async task processing and scalable queue-based architectures
CI/CD security practices - vulnerability scanning, dependency management
Observability - logging, tracing, monitoring at scale
Experience with Python-based backends in high-load environments
The role requires hands-on problem-solving ability, not just configuration experience. The candidate will be expected to advise on architecture decisions.

Location: Warsaw!
Start: as soon as possible
Duration: long-term
Languages: Polish is mandatory !! English: B2

Project domain: telecommunication

Hybrid: 1-2x week in Warsaw | 5+ years Java exp | English B2+
 

• Backend Core: Expert-level Java 21+ (Virtual Threads, Records) and Spring Boot 3.x production proficiency.
• Reactive & Security: Spring WebFlux/WebClient for non-blocking I/O; Spring Security with OAuth2/JWT validation.
• Event-Driven Architecture: Designing high-scale ecosystems with eventual consistency, idempotency, and process orchestration.
• Migration Leadership: Leading domain-specific transitions from Java to Node.js/TypeScript (Key Differentiator).
• API Design: Contract-first development with OpenAPI 3.x and automated client generation.
• Database & State: Spring Data MongoDB (document modeling) and distributed state handling with Redis/Caffeine.
• Observability: Micrometer, Prometheus, and OpenTelemetry for distributed tracing and post-mortem analysis.
• Resilience: Advanced Resilience4j implementation (retries, backoffs, rate limiting, and graceful degradation).
• Testing & Tooling: Spock/Groovy (BDD), WireMock, and Maven multi-module management.

Location: Warsaw!
Start: as soon as possible
Duration: long-term
Languages: Polish is mandatory !!, English: B2

Project domain: telecommunication

Hybrid: 1-2x week in Warsaw | 4+ years Architect exp | English B2+
 

• Systems Design: Mastery of DDD (Bounded Contexts, Ubiquitous Language) and distributed systems (CAP theorem, eventual consistency).
• Tech Evaluation: Strategic oversight of TS/Node/Bun, React 19, PostgreSQL, Kafka, and Kubernetes.Migration Patterns: Lead execution of Strangler Fig, Anti-Corruption Layers (ACL), and Branch by Abstraction strategies.
• Documentation: Establishing organization-wide SDD standards using C4 Model and Diagrams-as-Code (Mermaid/PlantUML).
• API & Commerce: Designing Headless/Composable architectures using OpenAPI 3.1 and oRPC for multi-channel orchestration.
• AI Orchestration: Designing agentic workflows to translate SDDs into architectural skeletons and code templates.
• Security & Resilience: Implementation of STRIDE threat modeling, Zero Trust principles, and Circuit Breaker/Bulkhead patterns.
• Validation: Spending 40% of time on technical spikes, POCs, and high-level code reviews to ensure compliance.

Location: Warsaw!
Start: as soon as possible
Duration: long-term
Languages: Polish is mandatory !!, English: B2

Hybrid: 1-2x week in Warsaw | 4+ years React exp | English B2+
 

• Core Stack: Expert-level React 19+ (Hooks, Suspense, RSC) and TypeScript (Strict Mode, Utility Types, Generics).
• Architecture: Next.js (Web) and Turborepo/Nx for unified monorepo management across platforms.
• State & Forms: XState/TanStack Query (no Redux), Zod, React Hook Form, and nuqs for type-safe params.
• Styling & UI: Tailwind CSS v4+ and NativeWind for cross-platform component consistency.
• Performance Engineering: Expert profiling of Core Web Vitals (LCP, INP, CLS) and React Native bridge/memory optimization.
• Quality Assurance: Vitest, React Testing Library, and Playwright with a focus on 80%+ critical path coverage.
• BFF & API: Next.js API routes and oRPC for end-to-end type safety.
• AI & Security: Designing agentic workflows for dev-velocity; expert OWASP Top 10 mitigation and dependency auditing.

Summary:
Our client is searching for an experienced Python Developer to join their team.

General Information:
The client is a leading agriculture company helping to improve global food security by enabling millions of farmers to make better use of available resources.

Tasks and Deliverables:
- Design and implement solutions using Python and Azure services to address various business problems.
- Conduct experiments and prototype new concepts to improve existing processes and to explore new capabilities.
- Maintain and optimize existing systems for performance and scalability.
- Document processes, systems, and protocols for internal and external stakeholders.
- Ensure compliance with data privacy and protection regulations.

Required Experience:
Strong programming skills in Python and familiarity with common data science libraries (e.g., NumPy, Pandas, Scikit-learn).
In-depth knowledge of Azure services and cloud architecture.

Nice to have
- Proven experience as an AI Engineer or similar role.
- Experience with Bedrock AI platform for model management and deployment.
- Familiarity with Langchain for integrating language models.
- Understanding of machine learning frameworks (e.g., TensorFlow, PyTorch).
- Experience with Natural Language Processing (NLP) and computer vision

Engagement highlights:
Work in a big enterprise company on exciting global projects

Detailed Required Skills: FastAPI, Python, NumPy, LangGraph, Artificial Intelligence (AI), Pandas, Azure, LangChain
Job Timezone: Asia/Kolkata
Work Type: Remote
Estimated Length: 6-12 months

Project Description:
Our client is building data- and AI-driven solutions in a cloud-first environment, with a strong focus on GCP, BigQuery, and large-scale data workflows. The current work is centered around exploring and defining new solution directions, especially in voice-related use cases, where architecture decisions must balance feasibility, scalability, and production readiness.
The environment is highly collaborative and cross-functional, bringing together technical leadership, data scientists, and engineering teams to shape complex solutions from early discovery through implementation.

We are hiring a Solutions Architect to help define and shape solution architecture for new data- and AI-driven initiatives.
This is an architecture-focused role working on GCP-based systems, big data modeling, and agentic / LLM-oriented solution design, with a strong emphasis on turning ambiguous requirements into clear technical options.
You will work on early-stage solution design, feasibility analysis, production architecture planning, and proof-of-concept preparation. The role is especially relevant for candidates with experience in voice data, call-agent systems, or similar real-time / unstructured data environments.

Required skills:
Tech Stack !!!:

• Python
• GCP
• BigQuery
• SQL / data modeling
• Large-scale data systems
• LLM / agentic solution design
• Streaming systems (nice to have)
• Voice / call-agent environments (strong plus)

What We’re Looking For !!!:

• Strong experience with GCP and cloud-native architecture;
• Strong Python background;
• Deep understanding of big data, data modeling, and analytical storage systems;
• Experience designing scalable, production-oriented architectures;
• Ability to operate in ambiguous environments and translate ideas into solution options;
• Strong communication and documentation skills;
• Ability to explain trade-offs clearly and collaborate across technical streams.

Interview process:

• EnglishCheck
• Internal Tech Interview
• Interview with the client

Responsibilities:

• Define architecture options for new data and AI solutions
• Evaluate technical feasibility of proposed voice-agentic systems
• Design production-grade solution approaches on GCP, especially around BigQuery
• Work with large, unstructured datasets and define storage / transformation strategies
• Support solution design involving LLMs and agentic workflows
• Prepare architecture documentation and technical recommendations
• Help shape proof-of-concept direction and technical scope
• Collaborate closely with technical leadership, data scientists, and engineering teams

Need overlap with Australia timezone !!!

We are looking for a Java developer with experience in building high-performing, scalable APIs and web applications.
You will be a part of a talented software development team that works on internal and external Company’s applications. You will work on new APIs as well as on supporting existing applications, refactoring, and creating new solutions, building scalable distributed systems, and integrating AI-powered capabilities into existing platforms.

Responsibilities
● Contribute in all phases of the development lifecycle including the communication with the clients and partners
● Helping Project manager to figure out the requirements and translate them to the actual tasks for the team
● Write well designed, testable and efficient code
● Ensure designs are in compliance with specifications
● Prepare and produce releases of software components
● Support continuous improvements by investigating new technologies and alternatives and presenting them for architectural review AI / Intelligent Systems Responsibilities
● Integrate AI/LLM-based capabilities into backend systems (e.g., APIs, data pipelines, internal tools)
● Design reliable orchestration flows for AI components (prompt pipelines, tool usage, fallback logic)
● Implement observability for AI systems (latency, cost, error rates, unsafe outputs)
● Ensure proper governance: validation, policy enforcement, and safe handling of AIgenerated outputs
● Work with structured and unstructured data sources to support AI-driven features
● Collaborate on designing systems where AI is a component of a larger architecture, not a standalone solution

Requirements!!!
● BS/MS degree in CS, Engineering or similar subject
● Good English
● 5+ years of proven hands-on software development experience
● Excellent knowledge of Java 17+
● Experience in Spring and Spring boot frameworks
● Experience with test-driven development
● Experience in developing web applications and REST APIs
● Good knowledge of *nix based OS
● Experience with K8s and building scalable multipod APIs
● Experience with next stack: JPA, Hibernate, AMQP(RabbitMQ/Kafka), SQL and noSQL databases, Feign, REST template, web sockets, OAuth2.0, JWT, Lombok, ElasticSearch AI / Data Experience (Preferred)
● Experience integrating external AI services (e.g., OpenAI, Anthropic, or similar) via APIs
● Understanding of prompt design and limitations of LLM-based systems
● Experience building or integrating RAG pipelines (vector search, embeddings, retrieval systems)
● Familiarity with data pipelines and preprocessing for AI-driven features
● Understanding of failure modes in AI systems and how to design around them
● Experience implementing guardrails, validation, and fallback mechanisms
Nice to Have
● Experience designing AI systems in regulated environments (compliance, auditability, traceability)
● Understanding of system-level AI architecture (separation of orchestration, business logic, and model layer)
● Experience with monitoring and cost control for AI workloads

We are seeking a skilled backend developer to take ownership of our trading account integrations, reporting, and subscription management systems. This role is critical to ensuring our prop firm runs reliably around account lifecycle management, end-of-day processing, subscription sync, and account integrity across multiple third-party trading platforms.
The ideal candidate has experience integrating with trading platform APIs (Tradovate, Rithmic, Ignite, cTrader, MetaTrader, CQG, or similar), strong REST API skills, and a track record of building reliable, failsafe systems in a high-volume trading environment.

Key Responsibilities 
● Own and manage all trading platform integrations — account creation, suspension, reactivation, and balance adjustments across our API (currently Ignite/Tickblaze) and any future platform integrations.
● Take full responsibility for end-of-day reporting workflows — ensure reports run reliably, process correctly, and update trader dashboards without disruption.
● Build monitoring and alerting around EOD failures, sync issues, and webhook delivery failures, so problems are caught before they impact traders or dashboards.
● Develop automatic recovery systems (retry logic with exponential backoff, token refresh, idempotent operations) to minimize downtime and manual intervention.
● Reconcile WooCommerce subscription statuses with trading accounts to ensure only paid users retain active accounts.
● Create audit tools to detect and clean up ghost accounts, orphan statistics, and balance chain inconsistencies.
● Handle webhook integrations with signature verification (Ed25519, HMAC) and replay protection.
● Collaborate with the WordPress/WooCommerce developers to ensure a smooth subscription-to-account creation flow.
● Maintain clear documentation and SOPs for all integration processes.
● Stay updated on trading platform API changes and best practices.

Qualifications Required 
● Proven experience integrating trading platform APIs in production. Rithmic (R|API+, RTrader Pro SDK), Tradovate, Ignite, cTrader, MetaTrader, or CQG all qualify — the underlying account management patterns transfer across platforms.
● Strong C# experience for backend service development.
● Experience with REST API consumption including pagination, retry logic, rate limiting, and authentication token management.
● Experience with webhook implementations including signature verification
(Ed25519, HMAC) and idempotent event processing.
● Experience building robust error handling, monitoring, and failover systems. As this system handles large amounts of money, resilient systems that notify on failures and handle them gracefully are critical.
● Strong SQL skills (PostgreSQL preferred) including debugging data integrity issues across related tables.
● Ability to work independently while coordinating with other developers on the team.

Preferred 
● Exposure to prop firm infrastructure, trader risk management, or drawdown/payout systems.
● Java / Spring Boot experience (current primary codebase; planned migration to C#).
● Docker and cloud deployment experience (AWS, DigitalOcean, Azure, or similar).
● CI/CD pipeline experience (GitHub Actions, GitLab CI, or similar).
● Exposure to compliance and audit requirements in fintech.
● Experience debugging distributed system issues — duplicate events, race conditions, cross-system timing bugs.

Work Environment & Expectations 
● Fully remote contractor engagement.
● Must maintain at least 5 hours of overlap with U.S. Eastern Time for meetings and collaboration.
● High responsiveness and accountability in a fast-moving, global team environment.
● Engagement typically requires 40+ hours per week, with flexibility to manage your own schedule while meeting deadlines.
● The system is up and running in production. You will be taking ownership of an
established integration stack and will have support during onboarding.