Kozak Agency

We are looking for a Growth Engineer to grow our products, mainly through code.

First one is a Shopify app that lets merchants add customizable sections to their stores. Second one is an AI store builder that uses first one as part of its product workflow. Together, they operate as one connected Shopify platform.

This is not a product engineering role. You will not be building core product features. You will be designing and building the systems that bring in users: analytics and funnel tracking, SEO/AEO, AI workflows that automate outreach, affiliate and referral programs, and anything else that drives growth.

You will work directly with the founder, who will set the direction and priorities. You will own how we get there: deciding what to try, building it, measuring the results, and iterating. Your first goal will be to set up tracking with PostHog. After that, a typical day will include reviewing data, finding new growth opportunities, and building and improving the workflows that act on them.

We are an AI-first company. We use AI wherever it saves time, and we expect you to do the same. You’re responsible for reviewing and testing everything before it ships.

Responsibilities
- Set up analytics across our apps
- Ship fixes and experiments based on that data
- Improve SEO and AEO so we show up when people ask Google, ChatGPT, Claude
- Build AI workflows in code (not with n8n, Make, or Zapier) to automate growth tasks, such as finding potential new users
- Build on our affiliate and referral programs
- Create simple reports that show what’s working and what to try next
- Propose and own new growth ideas once the basics are running

What Success Looks Like:
- Data Tracking is set up across our apps with data in one place so its easy to read
- We have baselines to measure every change against
- Funnel conversion is improving, and new acquisition channels are bringing in users
- You are coming up, and implementing your own growth strategies

Requirements:
- Strong TypeScript skills (React, Next.js, Node.js)
- Has grown something before (a product, app, store, or audience) and can share the results
- Has set up product analytics before with PostHog, Mixpanel or Amplitude.
- Has built AI workflows with LLM APIs, and uses AI coding tools daily
- Strong professional written and spoken English
- SEO/AEO experience

Builds and evolves data-heavy product interfaces on a TypeScript stack, owning features end to end from the API layer through to the UI, with a focus on usability and performance under real data volumes.
 

Key Responsibilities:
Build and maintain data-heavy product interfaces using Angular and TypeScript
Develop backend services and APIs with NestJS
Own features end to end — data model, API contract, UI implementation and tests
Implement complex tables, filtering, aggregation and visualisation that stay performant at scale
Design and maintain state management and component structure as the product grows
Write and maintain automated tests, and participate in code review and engineering standards
Work with product and design to shape how complex data is presented to users
 

Requirements:
6+ years of commercial full-stack experience
Fluent English
Strong TypeScript expertise
Recent production experience with modern Angular (not legacy AngularJS only)
Hands-on NestJS backend experience
Proven experience building data-heavy interfaces — complex tables, filtering, visualisation and performance optimisation
Solid REST API design and integration experience
Strong Git, pull request and code review practice
Ability to work independently and take ownership of delivery
 

Nice to Have:
Cypress or equivalent E2E testing experience
State management at scale (NgRx or similar)
RxJS and reactive programming patterns
Experience with design systems and reusable component libraries
Experience with AI-assisted development tools
Experience in the energy sector
Availability to work a Sunday–Thursday working week

We’re looking for an experienced Delphi/Object Pascal Developer to work on established healthcare software products where stability, performance, and backward compatibility are essential.

Must-have skills:
 Several years of senior-level Delphi development
 Strong experience with large Windows desktop applications
 Solid knowledge of VCL and Delphi application architecture
 Strong debugging and troubleshooting skills
 SQL and relational databases
 Experience maintaining and modernizing production codebases
 Fluent English

Nice to have:
 Windows API, COM/ActiveX
 Oracle or other enterprise databases
 Integration with C++, .NET, or Java
 Automated testing and CI/CD
 AI-assisted development tools

Remote — must be able to work from within the EU
Full-time, long-term contract
Start: ASAP

English - B2-C1
Rate - Flexible

We are looking for a Senior Go Developer to join our engineering team and work on a long-term product development project.
 

Requirements

• 5+ years of commercial software development experience
• Strong hands-on experience with Go / Golang
• Experience building and maintaining production backend systems
• Good understanding of software architecture and development best practices
• Experience designing and developing APIs
• Ability to write clean, maintainable and well-tested code
• Experience working with Git and modern development workflows
• Strong problem-solving skills
• Ability to work independently and take ownership of technical tasks
• Good communication skills and ability to collaborate with a development team
   

Responsibilities

• Develop and maintain backend services using Go
• Design and implement new features and APIs
• Participate in architectural and technical decisions
• Write and review production-quality code
• Improve system reliability, performance and maintainability
• Collaborate with other engineers and stakeholders
• Contribute to technical documentation and development best practices
   

Tech Stack

• Go / Golang
• Backend / APIs
• Git
• Modern software architecture

Location: Remote, EU
Duration: Longterm
Workload: Fulltime 40 hrs
Start: ASAP
Languages: English (min. B2). German (min. C1)
Interview rounds: 2-3
Location: Remote, office possible

Responsibility for mission-critical banking systems: help build the next generation of cloud-native banking software.
You'll work with Spring, microservices and Kubernetes on systems that banks rely on, and actively shape both architecture and product.
Our client develops cloud-native banking software and is looking for a Software Developer to strengthen its development team.

Overview

• Location: Remote, office possible
• Working hours: Full-time, 40 hours per week, flexible scheduling
• Focus: Java, Spring, microservices, Kubernetes

Your responsibilities

• Further development of existing microservices, plus analysis, design and implementation of new features together with product management
• Making and justifying architecture decisions as a team
• Code reviews and technical onboarding of new team members
• Creating and maintaining automated tests
• Active support in the deployment process

Your profile

• Professional experience as a software developer in product development
• Very good knowledge of Java and the Spring Framework
• Understanding of banking processes
• Fluent German (C1) in speech and writing, as technical coordination within the team, with product management and with customers is usually conducted in German
• Experience with agile software development
• Experience with cloud-native environments

Workload: full-time, remote
Start: asap
Duration: long-term (6-12 months anticipated, final term TBD)
Location: any (Europe timezone alignment)
English: B2/C1

Working Hours: 8 hours/day | Core availability 10:00-17:00 UK time, with flexibility for overlap with Eastern Canada
Hardware: Candidate may use their own laptop; VPN required for production changes or production-data investigation   

RESPONSIBILITIES

Virtual Signer Engineering
• Maintain and improve the Go Virtual Signer, including signing orchestration, communication between participants, encrypted storage, and recovery from failures.
• Investigate concurrency, timeouts, interrupted sessions, network failures, and service restarts; review outstanding pull requests and address race conditions.
• Improve logging and visibility, assess the existing implementation critically, and make careful, maintainable changes.
• Support agreed transaction approval features and future post-quantum signature work.
Cryptography, SDKs & Cross-Platform Integration
• Maintain integrations with MPC and threshold-signature libraries, working with cryptography specialists where changes affect protocol security.
• Contribute to shared SDKs and bindings connecting Go with Swift, Kotlin, and JavaScript/TypeScript.
• Work with backend and mobile engineers to preserve API compatibility and consistent signing behavior across releases.

Quality, Testing & Operations
• Improve automated tests for signing correctness, failure recovery, and interoperability between virtual and mobile signers.
• Support Linux and Docker deployments, dependency upgrades, monitoring, release processes, and operational documentation.

Ownership & Technical Judgment
• Take primary ownership of a security-critical codebase with limited handover and independently establish a robust production baseline.
• Assess technical risks and trade-offs, explain decisions clearly, and make incremental changes with sound security judgment.
• Collaborate pragmatically with backend, mobile, testing, and cryptography specialists across time zones.

REQUIREMENTS !!!
Essential Technical Experience
• Strong hands-on production Go, including goroutines, channels, context cancellation, race detection, profiling, and resource management.
• Experience owning production services, diagnosing complex failures, and delivering well-tested fixes.
• Distributed-systems knowledge, including asynchronous messaging, retries, idempotency, state management, and partial failures.
• Practical security engineering: authentication, encrypted storage, sensitive-data handling, and safe logging.
• Applied cryptography concepts, including digital signatures, hashing, key management, and signature verification.
• Automated testing, CI/CD, Linux, containers, and production observability.
• Ability to understand an established codebase, make careful incremental changes, and explain technical decisions clearly.

Strongly Preferred / Desirable Technical Experience
• JavaScript/TypeScript SDKs and mobile bindings, including asynchronous APIs, packaging, compatibility, and Go/mobile interoperation.
• React Native/Expo, Swift, or Kotlin; experience with mobile lifecycle, secure storage, or native modules.
• MPC or threshold signatures, distributed key generation, and changes to signing participants.
Blockchain transaction signing, including signing payloads and chain-specific requirements.
• Confidential computing and hardware attestation, particularly AMD SEV-SNP, are especially valuable among the desirable skills.
• MQTT, Protocol Buffers, Prometheus, or Open Telemetry; familiarity with post-quantum signature schemes is also desirable for the longer-term roadmap.