DevBrother

Our client is an innovative cryptocurrency and fintech startup focused on building secure, scalable, and user-friendly digital asset products and services for the retail market. Driven by a mission to simplify access to the crypto ecosystem, the company provides reliable infrastructure, seamless transactions, and exceptional user experiences. As an agile, forward-thinking organization, they are positioned to capture significant market share by bridging the gap between traditional finance and decentralized digital assets.
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Position Summary
​We are seeking a veteran, exceptionally skilled Hands-on Technical Lead to act as the ultimate Key Person and architect of our engineering ecosystem. This is a high-impact, elite technical role tailored for an absolute master of the JavaScript/TypeScript landscape who thrives when building complex platforms from the ground up.

​Initially, you will lead from the front lines by getting your hands dirty in the codebase—architecting and writing the core high-performance engine for our proprietary cryptocurrency exchange.

As you establish the initial code baseline, you will act as the foundational pillar to build and scale a brilliant team around you. For the right individual, this role offers an immediate and structured pathway to transition into the Chief Technology Officer (CTO) position as the company grows.

​This role is designed for a technical heavyweight who loves coding, architecture, and team design. You will write the core engine, set the standards, and transition into executive leadership as the engineering organization scales.

Key Responsibilities

• ​Hands-on Development & Architecture: Architect and implement robust, highly optimized backend systems using JavaScript/TypeScript (Node.js) for exchange infrastructure, order books, and transactional systems.
• ​Team Building & Growth: Serve as the central hiring pillar. Screen, recruit, and assemble an elite group of engineers to build a team around your technical vision.
• ​Technical Leadership & Standards: Set pristine code standards, architecture principles, and secure coding practices across the entire codebase. Mentor and coach incoming engineers.
• Product-to-Tech Alignment: Partner closely with business stakeholders to rapidly translate high-level product strategies into performant, clean technical implementations.
• ​Security & Resilience: Personally oversee the secure design of hot/cold wallet mechanics, API routing, matching systems, and regulatory reporting capabilities within the JavaScript stack.

​Required Qualifications & Experience

• ​Minimum 15 years of professional experience in software development and technical leadership.
• ​Mandatory Fintech/Trading/Crypto Exchange Background: Extensive experience building, maintaining, or optimizing trading platforms, complex transactional systems, or cryptocurrency exchange frameworks.
• ​JavaScript/TypeScript Mastery: World-class expert level in the JavaScript ecosystem. Deep, thorough understanding of asynchronous programming, Node.js memory management, event loop optimization, and building highly scalable, low-latency microservices.
• ​Foundational Team Builder: Demonstrated track record of acting as a "Key Person" whom previous engineering teams look to for direction and around whom technical talent naturally gathers.
• ​Executive Trajectory: Possess the strategic vision, communication skills, and high emotional intelligence required to swiftly step into a Chief Technology Officer (CTO) role.
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What We Offer

• ​A direct, fast-track trajectory to the Chief Technology Officer (CTO) title based on performance.
• Compensation plan that matches your status as a vital "Key Person."
• ​Technical autonomy to shape the architecture and team culture from the absolute beginning.
• Medical Insurance in Ukraine and Multisport program in Poland.
  Offices in Ukraine (Kyiv, Kharkiv) and Poland (Wroclaw) or Remote.
• Paid vacation, sick leaves, and official holidays.
• Legal & Accounting services.
• The company provides all necessary equipment.
• English classes and Education reimbursement.
   

We are looking for a motivated software engineer to join our engineering team. In this role, you will work across our entire stack to build products that are changing how users interact with the web safely. This is a perfect opportunity for an experienced developer ready to take on greater ownership and work with a modern, specialized tech stack.

The Role

You will be an integral part of our agile team, contributing to everything from our browser extension logic to our backend data pipelines. You’ll be expected to write clean, maintainable code, participate in design discussions, and help us scale our security-focused solutions.

Responsibilities:

• Feature Development: Design and implement product features across the full stack (React, Node.js, and C#).
• Code Excellence: Contribute to and uphold our code quality standards through thorough testing and thoughtful peer reviews.
• Rapid Problem Solving: Debug complex issues and ship fixes quickly to maintain a seamless user experience.
• Collaborative Engineering: Partner with teammates to brainstorm and solve architectural challenges creatively.
• Codebase Evolution: Take ownership of extending and optimizing our existing codebase as we add new capabilities.

Qualifications

• Experience: 2–4 years of professional software development experience.
• Education: BS/BA in Computer Science or a related field, or equivalent practical experience.
• Core Stack: Proven proficiency in TypeScript, Node.js, and React. 
• C# / .NET: Familiarity with the .NET ecosystem for backend services.
• Databases: Experience working with SQL databases, ideally PostgreSQL.
• Cloud & Tools: Comfort working in AWS environments and familiarity with Git and Jira.
• Communication: Strong verbal and written communication skills with a collaborative mindset.
• Drive: Self-motivated and capable of hitting the ground running in a fast-paced environment.

Our Tech Stack

We lean into modern tools to build fast and stay secure:

TypeScript · Node.js · React · PostgreSQL · AWS · Plasmo · C#/.NET

​Nice to Have

If you have experience in any of the following, you'll have a head start:

• ​Browser Extensions: Experience building or maintaining extensions (especially using frameworks like Plasmo).
• ​​Cybersecurity Knowledge: Interest or experience in data loss prevention (DLP), DNS security, or credentials analysis.
• ​Startup Savvy: Experience working in a startup or a similarly fast-moving environment.
• Design Literacy: Familiarity with Figma to help translate designs into functional code.

🎁 We Offer

• Growth: Daily support for your technical and personal growth through mentoring and educational programs.
• Team Culture: A professional and friendly environment where help is always available.
• Medical Insurance in Ukraine and Multisport program in Poland.
• Offices in Ukraine (Kyiv, Kharkiv) and Poland (Wroclaw) or Remote.
• Paid vacation, sick leaves, and official holidays.
• Legal & Accounting services.
• The company provides all necessary equipment.
• English classes and Education reimbursement.

We are building the next generation of AI Agentic Marketing Solutions specifically for the Game Development industry. We don’t just build simple chatbots; we build autonomous agents that plan, execute, and optimize User Acquisition (UA) and marketing campaigns for gaming studios.

We are looking for a versatile Product Engineer based in Europe to join our high-performance team and build the end-to-end features that power our agents.

The Role

You will be the bridge between our AI logic and the user experience. You will work across the entire stack—from developing AI agents to building the FastAPI endpoints that drive our agents that our clients use to manage their AI marketing teams.

Key Responsibilities

• Agents Development: Build and maintain AI agents and features from the database level up to the UI.
• Agent Integration: Work closely with our AI team to integrate LangGraph/LangChain workflows into the platform.
• API Design: Develop and optimize high-performance APIs using Python (FastAPI).

Requirements

• AI Expertise: Proven track record of building and scaling AI-powered products. You know the difference between a tutorial and a production-grade agentic system. While you don't need to be an AI researcher, you should have experience with LLM integration and agentic frameworks. 
• Engineering Mastery: 5+ years of experience in software engineering. Solid Python skills with a focus on asynchronous programming (FastAPI, AsyncIO). Familiarity with PostgreSQL, Redis, and modern CI/CD practices. 
• Agentic Frameworks: Deep experience with LangGraph, LangChain, and/or similar libraries.
• Product Mindset: You care about the user experience and understand how your code impacts the business goals of our GameDev clients. 

What We Offer

• High Impact: No bureaucracy. Your code shapes the future of GameDev marketing.
• Elite Team: Work alongside senior experts who value "Delivery in 1 Second" and relentless improvement.
• Medical Insurance in Ukraine and Multisport program in Poland.
• Offices in Ukraine (Kyiv, Kharkiv) and Poland (Wroclaw) or Remote.
• Paid vacation, sick leaves, and official holidays.
• Legal & Accounting services.
• The company provides all necessary equipment.
• English classes and Education reimbursement.

We are building the next generation of AI Agentic Marketing Solutions specifically for the Game Development industry. We don’t just build simple chatbots; we build autonomous agents that plan, execute, and optimize User Acquisition (UA) and marketing campaigns for gaming studios.

We are looking for an AI Jedi—a top-tier engineer who lives and breathes agentic orchestration and can solve the most complex problems in the LLM space.

The Role

This is a high-impact, individual contributor role for a master of AI engineering. You will be responsible for the "brain" of our platform. We need someone who can move beyond basic RAG and prompt engineering to build sophisticated, self-correcting, and autonomous agentic workflows that deliver results for the world’s biggest gaming studios.

Key Responsibilities

• Architecting Autonomy: Design and implement high-level agentic orchestration using LangGraph or custom state-machine frameworks.
• AI Excellence: Solve complex challenges related to agent memory, long-term planning, and multi-agent collaboration.
• Performance & Reliability: Build robust evaluation loops and guardrails to ensure our agents perform reliably in production environments.
• Innovation: Stay at the absolute bleeding edge of AI research, quickly turning new papers and techniques into production-ready features.

Requirements

• Deep AI Expertise: Proven track record of building and scaling AI-powered products. You know the difference between a tutorial and a production-grade agentic system.
• Python Mastery: Expert-level Python skills with a focus on asynchronous programming (FastAPI, AsyncIO).
• Agentic Frameworks: Deep experience with LangGraph, LangChain, and/or similar libraries.
• Infrastructure Savvy: Comfortable with Vector Databases, high-scale data pipelines, and cloud infrastructure (AWS/K8s).
• Startup DNA: You are a "Builder." You value speed, pragmatism, and shipping code that works over theoretical perfection.

What We Offer

• High Impact: No bureaucracy. Your code shapes the future of GameDev marketing.
• Equity & Growth: A fast-track path to a key leadership role with a stake in the company’s success.
• Elite Team: Work alongside senior experts who value "Delivery in 1 Second" and relentless improvement.
• Medical Insurance in Ukraine and Multisport program in Poland.
• Offices in Ukraine (Kyiv, Kharkiv) and Poland (Wroclaw) or Remote.
• Paid vacation, sick leaves, and official holidays.
• Legal & Accounting services.
• The company provides all necessary equipment.
• English classes and Education reimbursement.

We are looking for a highly motivated Trainee Full-stack Developer to join our team. You will work on an innovative project focused on browser security and privacy tools. This is a unique chance to kickstart your career in a product-led environment, learning from senior engineers while contributing to real-world security solutions.

Requirements:

• Bachelor's degree in Computer Science, or related field.
• Solid foundational knowledge of JavaScript (ES6+).
• Basic experience or projects built with Node.js and backend principles (REST APIs).
• Understanding of React.js.
• Familiarity with TypeScript is a significant plus, but not mandatory.
• Willingness to learn new frameworks (e.g., Fastify) and security-focused patterns.
• English Proficiency: Strong spoken English is mandatory — level: Minimum B1 (Intermediate), ideally B2 (Upper-Intermediate). You must be able to comfortably discuss technical tasks and participate in team meetings.

What you will do:

• Develop and maintain web applications using React and Node.js.
• Collaborate with the team on building secure browser extension features.
• Participate in code reviews and learn to write production-grade code.
• Engage in daily stand-ups and agile processes.

We thank you to all those who apply, however, there is a possibility from our side, of not responding to some candidates who do not match the requirements, due to a large number of applicants. Thank you for your understanding.

We Offer:

• Opportunity to join a prospective product team and work on a cutting-edge solution in the security domain.
• Competitive compensation during the internship period.
• Direct mentorship from experienced software engineers.
• A flat management structure with no unnecessary bureaucracy.

We are looking for a skilled and mature Software Engineer to join a stable startup based in New York dedicated to developing cutting-edge browser security solutions. Our mission is to provide users with a secure and private online experience. We are a close-knit team of passionate individuals who thrive on creativity and collaboration. As we continue to grow, we are seeking talented individuals to join us in building a safer digital future.

We are seeking engineers who are passionate about building innovative solutions and high-quality software. Our ideal candidate works diligently to solve complex problems, appreciates a culture of learning and collaboration, and is invested in the future of security.

You will play a crucial role in enhancing the security and privacy features of the product, ensuring a seamless and protected online experience for our users.

Requirements:

• Bachelor's degree in Computer Science, related field, or equivalent practical experience.
• 2+ experience as a Software Engineer with experience in TypeScript, Fastify, NodeJS, and Next.js.
• Solid understanding of web security principles and best practices.
• Experience with browser extensions and security software products is a plus.
• Strong problem-solving skills and attention to detail.
• Excellent communication and collaboration skills in a remote work environment.

Responsibilities:
 

• Collaborate with cross-functional teams to design, develop, and deploy high-quality software solutions for browser security.
• Write clean, maintainable, and efficient code using TypeScript, Node.js, and Next.js.
• Conduct code reviews to ensure code quality and adherence to coding standards.
• Work closely with product managers and UX/UI designers to implement new features and improvements.
• Identify and address performance bottlenecks, security vulnerabilities, and other issues proactively.
• Participate in the agile development process, including sprint planning, daily stand-ups, and retrospectives.

We thank you to all those who apply, however, there is a possibility from our side, of not responding to some candidates who do not match the requirements, due to a large number of applicants. Thank you for your understanding.

We Offer:

• Medical Insurance in Ukraine and Multisport program in Poland.
• Offices in Ukraine (Kharkiv) and Poland (Wroclaw) or Remote.
• Paid vacation, sick leaves, and official holidays.
• Legal & Accounting services.
• The company provides all necessary equipment.
• English classes and Education reimbursement.

We are an innovative AI tech lab building next-generation infrastructure for fully autonomous AI systems. We are currently scaling two core bleeding-edge products:
 

1. An Autonomous Agent Framework: A highly autonomous, "configure-once, forget-forever" agent platform that runs complex workflows, manages its own skills, self-corrects outputs, and operates without traditional approval loops or babysitting.
2. An Intelligence Engine: A massive-scale simulation platform capable of spawning hundreds of grounded AI agents within minutes to simulate real-world behavior, interact across social platforms (Twitter, Reddit), trade on prediction markets, and generate comprehensive counterfactual analysis reports.
    

We are looking for a Senior Backend Developer who is passionate about LLMs, multi-agent orchestrations, graph databases, and building autonomous workflows that operate seamlessly 24/7.
 

Core Responsibilities

• Architect Agent Lifecycles: Design, extend, and optimize the backend core responsible for autonomous agent task execution, state management, and memory retention.
• Scale Swarm Simulations: Improve the performance of multi-agent simulation environments, ensuring concurrent execution of hundreds of agents making API calls, processing text, and updating states in real time.
• Expand the Skills Library: Develop and integrate new "skills" and MCP (Model Context Protocol) tools for agents (e.g., automated code/PR reviews, web searching, live market monitoring, API integrations).
• Self-Healing & Quality Loops: Enhance automated fallback mechanisms, error handling, and self-patching algorithms where AI models evaluate their own outputs and fix failing tasks without human intervention.
• Data & Graph Modeling: Optimize data storage, retrieval, and relational modeling for agent memories, social graphs, and prediction market consensus.

Technical Requirements & Stack

• Languages: Deep proficiency in Python and Node.js/TypeScript (strong backend fundamentals are non-negotiable).
• AI & LLM Integration: Practical experience working with LLM APIs (OpenAI, Anthropic Claude, Ollama) and vector embeddings. Understanding of prompt chaining and structured outputs.
• Databases: Solid experience with Graph Databases (e.g., Neo4j) as well as relational or NoSQL solutions.
• Automation & CI/CD: Strong knowledge of GitHub Actions (used as a runtime framework), workflow dispatches, and containerization (Docker).
• Integrations: Experience building and consuming webhooks, REST APIs, and integrating with third-party platforms (Discord, Slack, Twitter/X, Reddit, or financial data feeds).
• Architecture: Familiarity with event-driven architectures, parallel/sequential task processing, and file-based state logging (Markdown/JSON).

Nice to Have

• Experience or strong interest in Web3, DeFi, and Prediction Markets (Polymarket, Base network ecosystem, tokenomics).
• Open-source contributions or a history of building custom AI tools/bots.
• Familiarity with local LLM deployment and inference optimization.

What We Offer

• 100% Remote & Flexible: Work from anywhere with asynchronous-friendly communication.
• Cutting-Edge Tech: No legacy enterprise maintenance. You will be shipping code to production for autonomous systems from day one.
• High Autonomy: Just like our agents, we value builders who don’t need micro-management and can own features end-to-end.
• Medical Insurance in Ukraine and Multisport program in Poland.
• Offices in Ukraine (Kyiv, Kharkiv) and Poland (Wroclaw) or Remote.
• Paid vacation, sick leaves, and official holidays.
• Legal & Accounting services.
• The company provides all necessary equipment.
• English classes and Education reimbursement.