Design and Architecture web application

Pro

Vasiliy Kuzmenko

Starting at

$

75

/hr

About this service

Summary

Design clear, scalable backend architectures through data-flow diagrams, OpenAPI-based API specifications, and sequence diagrams for system interactions. I specialize in modeling complex data structures with ER diagrams and optimizing PostgreSQL storage and API queries for efficient, minimal data exchange.

Process

Requirements Analysis – Gather and clarify technical and business needs.
Data-Flow Diagramming – Visualize how data moves through the system.
API Design – Define endpoints and structure using OpenAPI specifications.
Sequence Diagram Creation – Map out interactions between services or components.
Data Modeling – Design data structures and relationships via ER diagrams.
Database Implementation – Structure and prepare to deploy the schema optimized for PostgreSQL.
API Optimization – Fine-tune queries to ensure minimal and efficient data exchange.
Sometimes it not that straight, because some decision and disclosure/discovery of data/processes required to make adjustments to previous steps.

FAQs

  • What tools do you use for designing APIs and data models?

    I primarily use OpenAPI (Swagger) via stoplight.io for API specifications, mermaidchart.com for diagrams, and dbSchema for data modeling and storage.

  • Can you work with existing systems or only new projects?

    I can do both. I’m experienced in analyzing and optimizing legacy systems as well as building structured, scalable APIs from the ground up. Existing systems mostly need to fix issues with overfetch unnecessary data, and create strong contracts between data providers (for both internal and external).

  • How do you ensure performance in your API designs?

    I focus on sending only the necessary data, use efficient query patterns in PostgreSQL, and design endpoints with performance in mind from the start.

  • Do you provide documentation as part of the process?

    Yes, I deliver comprehensive technical documentation, including OpenAPI specs, diagrams, and database schemas.

  • What kind of projects do you typically work on?

    Mostly web applications, internal tools, and data-driven platforms that require clear API structure, solid database design, and optimized data flow.

What's included

  • Architecture diagrams

    Architecture diagrams outlining how processes should works, in simple Flowchart diagrams, Architecture diagrams or even Archimate diagrams.

  • Data diagrams

    Class, Sequence, Entity Relationship, Database diagram in DbSchema format or exported to html/pdf format to view easily.

  • Documentation

    Document that describe and explain how process project to works with examples, explain data flows and decision.

  • OpenAPI Specification

    OpenAPI 3.x specification in json/YAML format or via stoplight.io

Skills and tools

Data Analyst

Researcher

Software Architect

Google Drive

Google Drive

LucidCharts

LucidCharts

PostgreSQL

PostgreSQL

Industries

Engineering & Architecture
Computer Software
Data

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