One operational picture
Reconcile relevant sources into consistent records, statuses and definitions for day-to-day work.
API and systems integration
API integration between ERP, CRM and other business systems.
Greenwall connects business applications, APIs and files so records and statuses move reliably between systems. We work remotely across Bulgaria and Europe, with client-site work in Sofia by arrangement.
The context
Agree which system owns each record and how changes reach the others.
Important data may live in PostgreSQL, spreadsheets, email attachments, third-party APIs, device messages or an older application that still serves the business. The first task is to understand meaning, ownership, quality and timing across those sources.
Example flow: an online store sends an order to an ERP, which returns a confirmation and order status. This is an illustrative scenario. Feasibility depends on the available APIs or export formats; we define identifiers, update direction, validation and reconciliation before implementation.
Business outcomes
What connected data makes possible
Reliable information should shorten the path between an event, an understanding and a response.
Faster analysis and research
Prepare data for trends, comparisons, mapping and questions that were previously difficult to answer.
Safer gradual change
Introduce new services and interfaces around valuable legacy systems without a disruptive all-at-once replacement.
Selected capabilities
Integration and data capabilities
The exact combination follows the problem, the existing environment and the people who will own the result.
- REST APIs and ERP, CRM or e-commerce synchronisation where supported
- ETL pipelines, validation, reconciliation and transformation
- Spreadsheet, CSV and document import and export workflows
- Email-based intake, attachments, notifications and follow-up
- PostgreSQL, PostGIS, InfluxDB and Cassandra data patterns
- MQTT, WebSocket and time-series ingestion for live data
- Search, maps, dashboards and 3D geospatial visualisation
Working process
Build trust in the data before building on top of it
- 01
Inventory sources and meaning
Identify systems, formats, owners, update frequency and the decisions each field supports.
- 02
Define contracts and quality rules
Agree identifiers, transformations, validation, lineage and handling of incomplete information.
- 03
Connect a bounded flow
Move a valuable set of data end to end with diagnostics, retries and reconciliation.
- 04
Expose useful access
Provide an API, workflow, map or analysis view that turns the integrated data into action.
Relevant experience
Data patterns from delivered and independent work
The experience ranges from enterprise imports to live device streams and public-data products.
Procurement and management data
Nik’s work within an employer-led engagement included structured spreadsheet import and export, validation and service APIs for purchasing and spend analysis.
Read the integration case studyIoT and market time series
MQTT and WebSocket sources have been processed into time-series storage, diagnostics, alerts and usable product views.
3D property intelligence
An independent platform combined cadastral, trade-register, statistical and OpenStreetMap data for parcel, building and market exploration.
Good fit
Situations where integration is the real product work
Operations with scattered sources
Teams make decisions across spreadsheets, inboxes, databases and vendor systems with no reliable shared view.
Products built on live information
Devices, markets or external services generate events that need timely processing and clear failure handling.
Legacy systems with continuing value
The organisation needs modern access and workflows without discarding a stable core prematurely.
Questions
API and systems integration questions
Can you connect systems that do not have an API?
Sometimes an authorised file import, export or documented database interface provides a suitable path. We first check the supplier’s supported options, access permissions and update needs. Feasibility is assessed before promising a connection.
Can public and internal data be combined?
Yes, when source terms, identifiers, update cycles, quality and access responsibilities are understood. The combined product should make provenance and uncertainty visible.
What happens when an integration fails?
Failure handling is designed into the flow through validation, logs, retries, reconciliation and a clear path for human review.
Contact
Turn disconnected sources into a dependable business flow.
Share the systems, formats and decisions that need to connect.