Jan Ivanisevic-Senior Software Engineer — Ai-Ready Full Stack Systems
Check rate
Experience
Senior Software Engineer
MyFreeApp
- Built and maintained application features across full-stack workflows for a remote product environment.
- Integrated external services into existing systems using API-driven patterns and clear data contracts.
- Supported AI-ready feature paths by structuring application flows for automation and third-party service connectivity.
- Tested new features across frontend and backend boundaries before release.
- Documented technical behavior and implementation notes for maintainability and team handoff.
Full Stack / AI Integration Consultant
Self Employed
- Delivered contract software engineering work across frontend, backend, and API integration tasks.
- Prototyped service integrations that could support conversational AI and voice automation workflows.
- Connected application logic with external APIs while managing validation, error handling, and configuration.
- Performed testing and defect resolution for client-facing software features.
- Prepared technical documentation for setup, handoff, and ongoing maintenance.
Full Stack Developer
Exoft
- Developed full-stack software features using JavaScript-based interfaces and backend service integrations.
- Implemented API-connected modules with clear request handling, validation, and response management.
- Improved existing application areas by refactoring integration logic and reducing coupling between components.
- Supported QA activities through troubleshooting, regression checks, and defect fixes.
- Collaborated with remote stakeholders to clarify requirements and deliver maintainable software changes.
Frontend Developer
Exoft
- Built user-facing web application features using JavaScript and component-based frontend practices.
- Integrated frontend modules with backend APIs and handled data loading, validation, and error states.
- Participated in testing and bug fixing for application releases.
- Worked with backend engineers to align UI behavior with API contracts.
- Maintained reusable frontend code patterns for future feature development.
Software Engineer
Diageo
- Developed internal software features and supported application maintenance for business workflows.
- Built API-connected functionality and handled data validation across application modules.
- Supported troubleshooting, testing, and release preparation for production systems.
- Worked with stakeholders to translate business needs into practical technical changes.
- Documented changes and technical behavior for internal engineering reference.
Junior Software Engineer
ING
- Implemented junior-level software features under established engineering standards.
- Assisted with frontend and backend maintenance tasks, bug fixes, and release support.
- Worked with databases, application logic, and basic API-connected workflows.
- Participated in testing and defect reproduction to support stable releases.
- Built foundational experience in structured software delivery, documentation, and team collaboration.
Industry experience
See where this freelancer has spent most of their professional time.
Experienced in Information Technology, Food and Beverage, Banking and Finance, and Professional Services.
Business area experience
See which departments and functions this freelancer has contributed to most.
Experienced in Information Technology, Product Development, Quality Assurance, and Operations.
Summary
Senior Software Engineer with long-term experience across full-stack development, backend services, and remote product delivery. Relevant to Voice AI projects through API integration, application work, backend patterns, testing, and documentation. Experienced in improving existing systems, connecting external services, and supporting production software workflows. Can contribute to ElevenLabs-based voice bot projects through integration work, conversational workflow support, and QA validation. Works well independently while collaborating with distributed engineering and product teams.
Skills
- Ai / Voice: Voice Ai Integration Patterns, Elevenlabs-Style Apis, Conversational Workflow Integration, Ai Service Connectivity
- Backend: Rest Apis, Backend Services, Integration Layers, Authentication, Data Validation
- Frontend: React, Javascript Ui Development, Product Workflow Integration
- Testing / Qa: Integration Testing, Api Validation, Regression Support, Defect Resolution
- Delivery: Remote Collaboration, Technical Documentation, Stakeholder Communication, Agile Implementation
Languages
Education
Lodz University of Technology
Bachelor's Degree · Computer Science · Poland
Statistics
Experience
Expertise
Qualifications
Profile
Frequently asked questions
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Jan is based in Warszawa, Poland.
Jan speaks the following languages: English (Advanced), Polish (Intermediate).
Jan has at least 11 years of experience. During this time, Jan has worked in at least 6 different roles and for 5 different companies. The average length of individual experience is 2 years and 10 months. Note that Jan may not have shared all experience and actually has more experience.
Based on recent experience, Jan would be well-suited for roles such as: Senior Software Engineer, Full Stack / AI Integration Consultant, Full Stack Developer.
Jan's most recent position is Senior Software Engineer at MyFreeApp.
In recent years, Jan has worked for MyFreeApp, Self Employed, and Exoft.
Jan is most experienced in industries like Information Technology, Food and Beverage, and Banking and Finance. Jan also has some experience in Professional Services.
Jan is most experienced in business areas like Information Technology, Product Development, and Quality Assurance. Jan also has some experience in Operations.
Jan has recently worked in industries like Information Technology and Professional Services.
Jan has recently worked in business areas like Information Technology, Product Development, and Quality Assurance.
Jan holds a Bachelor in Computer Science from Lodz University of Technology.
Jan is immediately available full-time for suitable projects.
Daily rate distribution
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Average rates for similar positions
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The average daily rate is the mean of all daily rates from recent contracts of comparable freelancers on our platform.
The median daily rate is the middle value of all daily rates — half of comparable freelancers charge less, half charge more. Unlike the average, it is barely affected by outliers.
Calculated based on our freelancers’ daily rates as of 6 Sep 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
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