Development services · Warsaw, Poland

API development Warsaw

Design, build and integrate APIs so your systems talk: REST, GraphQL, webhooks, OAuth and third-party connectors with clear documentation.

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API development & integration

✓RESTful API design with versioning and pagination
✓GraphQL schemas and resolvers
✓OpenAPI / Swagger documentation
✓OAuth2, API keys and rate limiting
✓Webhook receivers with signature verification
✓CRM/ERP connectors (HubSpot, Salesforce, Baselinker)
✓SOAP legacy bridges when enterprise clients require it

Integration architecture

Idempotent endpoints for payments and webhooks - duplicates must not double-charge.

Errors return consistent JSON with codes your frontend can handle.

I map fields between systems before writing glue code - mismatched IDs kill projects.

Polish integrations: InPost, PayU, Fakturownia, Subiekt GT APIs.

US integrations: Stripe, Twilio, SendGrid, Shopify Admin API.

API technologies

RESTGraphQLOpenAPILaravel SanctumJWTPostmanRedis queuesSOAP/XML

Warsaw · Poland · Europe · USA

Remote-first development with local presence in Warsaw - the same senior engineer for Polish, European and American clients.

Warsaw

API developer Warsaw - connect your app to Polish logistics and accounting tools.

Poland

B2B integrations for Polish wholesalers and marketplaces.

Europe

Cross-border API flows with GDPR-safe data mapping.

USA

SaaS API layers for US products integrating with mainstream US stacks.

Development + SEO

We do not only build - we promote

Public APIs and landing pages should be discoverable - alongside integration work I provide SEO so your product pages and docs attract organic traffic.

Website promotion & SEO

About me

I'm Viktar Liukevich

Full-stack developer · 15+ years creating web

I am Viktar Liukevich, an API developer in Warsaw. Half my backend work is integrations - REST, GraphQL, webhooks and OAuth with documentation your frontend team can rely on.

I map fields between systems before writing glue code - mismatched IDs kill projects. Polish flows use InPost, PayU and Fakturownia; US flows use Stripe, Twilio and Shopify Admin - always idempotent where money moves.

For SAP, Salesforce enterprise bridges or niche SOAP legacy connectors, I engage integration partners with deep stack expertise in Poland, Europe and the USA, under NDA. I own the API design and review every endpoint before production.

300+

Completed Projects

90+

Clients

10+

Partners

Advantages

15+ years working for myself
Wide technology stack
Rapid development
Warranty and support
Global quality standards
Working with clients worldwide
Innovative technological solutions

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