Junior Full-Stack Developer – AI, Data & Geospatial Technology

Junior Full-Stack Developer – AI, Data & Geospatial Technology
Company: PlanStream
Location: Remote - Slovakia preferred
Engagement: Freelance / part-time
Time commitment: Approximately 10 hours per week
Hourly rate: €20 per hour
Start date: As soon as possible
About PlanStream
PlanStream is an early-stage PropTech startup developing software to help planning consultants and architects streamline the planning application process in the UK.
The platform combines AI-powered planning research and document analysis with structured planning data and mapping functionality. This includes helping users research planning policies, analyse similar applications, process planning documents and access relevant planning information through interactive mapping tools.
We already have an existing MVP and are looking for a motivated junior developer to help improve the platform, resolve outstanding bugs and develop new functionality.
This is an opportunity to work across AI, software development, data processing and geospatial technology on a real product with potential for long-term growth.
About the role
We are looking for a proactive and resourceful Junior Full-Stack Developer who can work independently and take ownership of technical tasks.
You will work directly with the founder, who will provide product requirements, priorities and business context. However, you will be expected to investigate technical problems, research solutions, make appropriate implementation decisions and deliver agreed tasks without constant supervision.
The role covers several areas of development, including frontend and backend programming, Python-based data processing, database management, API integrations, AI functionality and mapping tools.
You do not need to be an expert in every area. We are looking for someone with solid programming fundamentals, an ability to learn unfamiliar technologies and the initiative to work independently with an existing codebase.
Key responsibilities
Review and understand the existing application, codebase and technical architecture.
Independently investigate and resolve bugs and technical issues.
Develop and maintain frontend and backend functionality.
Use Python and other appropriate technologies to process, clean, transform and structure planning-related data.
Work with databases, APIs and third-party data services.
Maintain and improve interactive mapping functionality displaying planning permissions, planning constraints and other relevant spatial information.
Work with geospatial data formats, spatial queries and mapping services where required.
Assist with integrating AI tools and large language model APIs into planning workflows.
Improve the processing and extraction of information from planning documents, PDFs and other datasets.
Implement new features based on agreed product requirements.
Test functionality, investigate errors and ensure changes do not break existing features.
Help maintain the database, application infrastructure and deployment processes.
Document technical changes and communicate progress, risks and blockers.
Support ongoing maintenance and further development as the platform gains users.
Essential skills and requirements
Practical programming experience through employment, internships, university projects or personal projects.
Familiarity with JavaScript or TypeScript and modern web development.
Basic knowledge of backend development, databases and API integrations.
Familiarity with Python, including writing scripts or working with data.
Understanding of Git and version control.
Ability to troubleshoot technical issues and research solutions independently.
Ability to take responsibility for tasks from investigation through implementation and testing.
Good problem-solving and analytical skills.
Clear communication and the ability to manage work within an agreed weekly commitment.
Desirable skills
Experience with some of the following would be advantageous:
Web development: React, TypeScript, Python, Node.js, Supabase, PostgreSQL and REST APIs.
Geospatial data: QGIS, PostGIS, GeoJSON, interactive mapping libraries (Leaflet/Mapbox) and spatial datasets.
AI and document processing: OpenAI APIs, PDF processing, OCR, data extraction, RAG and semantic search.
Infrastructure: GitHub, deployment, debugging and testing.
Experience with every technology is not required. Practical programming skills, independent problem-solving and willingness to learn are more important.
Working arrangements
Commitment: Approximately 10 hours per week.
Location: Fully remote, with candidates based in Slovakia preferred.
Engagement: Freelance / part-time, initially project-based.
Schedule: Flexible, provided agreed deliverables are completed and progress is communicated regularly.
Future opportunities: Potential for continued paid work as the product develops and acquires customers.
The founder will define product requirements and priorities, but the developer will have substantial autonomy over the technical implementation.
This is not a role where every technical step will be specified in advance. The successful candidate should be comfortable working independently, taking initiative and finding practical solutions.
Initial project objectives
The first engagement will focus on reviewing and improving the existing MVP.
Expected activities include:
Technical review: Understand the current architecture, codebase, integrations and outstanding issues.
Bug fixing: Identify and resolve the most important bugs and technical blockers.
Data and mapping functionality: Review existing data-processing workflows and mapping features, identifying improvements needed for reliability and usability.
Feature development: Implement agreed improvements across the frontend, backend, database and AI integrations.
Testing and launch preparation: Test the application and prepare it for use by initial customers.
Documentation: Document relevant technical changes, dependencies and deployment procedures.
The precise priorities will be agreed following an initial review of the application. Candidates should be able to estimate tasks, recommend implementation approaches and deliver independently within the agreed scope.
What we offer
Flexible remote working.
Meaningful technical responsibility and opportunities to influence implementation decisions.
The opportunity to contribute to an AI-powered PropTech product at an early stage.
Hands-on experience across software engineering, data processing, AI and geospatial technology.
Direct collaboration with the founder and involvement in product development.
Potential for a longer-term working relationship as the company grows.
This is an early-stage freelance opportunity rather than a guaranteed full-time position. The initial engagement and any subsequent work will depend on the agreed scope, budget and business requirements.
How to apply
Please send:
Your CV or LinkedIn profile to filip@planstream.co.uk.
Links to relevant projects, GitHub repositories or portfolio examples.
A short description of your experience with Python, web development, databases, APIs or geospatial data.
Your availability.
An example of a technical problem you solved independently and how you approached it.
We look forward to hearing from motivated developers who enjoy solving problems independently and want to help develop a product at the intersection of planning, data, mapping and AI.

Work arrangement
Yes