Konstantin Zhdanov

Software Engineer

Konstantin Zhdanov

About

Full-stack AI Software Engineer with 15+ years of experience building and scaling SaaS platforms. Proven expertise in leading frontend teams, modernizing legacy systems, and implementing AI-driven document automation. Strong background in JavaScript/TypeScript, React, Node.js, Next.js, RAG, and cloud-based CI/CD workflows.

Skills

JavaScriptTypeScriptReactReduxRedux-SagaNode.jsWebpackJestReact Testing LibraryPlaywrightC# ASP.NET MVCStorybookAWSGitHub actionsExpoReact NativeNext.jsDrizzle ORMTailwindCSS / SASSLokiGrafanaSentryKibanaGitSqlJiraAgilePDF.jsPostgreSQLPythonDockerDigitalOceanReact-QueryRedux-ToolkitRedis

Experience

· 15 yrs

Alpaca Relay

Part-time · 1 yr

Remote

AI Engineer

Oct 2025 - Present

Boston, Massachusetts, United States

  • • Architected and developed a full-stack AI application using Next.js and the OpenAI SDK, integrating a custom-built intelligent chatbot;
  • • Engineered a sophisticated AI backend using Python and DSPy, optimizing prompt engineering and model interactions;
  • • Implemented RAG for long-term agent memory, utilizing pgVector and PostgreSQL for efficient vector similarity search;
  • • Built a robust observability and A/B testing pipeline using TensorZero and ClickHouse to monitor model performance and optimize user experience;
  • • Designed a real-time notification system leveraging Redis and BullMQ for asynchronous event processing;
  • • Deployed and managed infrastructure on DigitalOcean, ensuring high availability and scalability.

airSlate

Full-time · 2 yrs 8 mos

Hybrid

Senior Software Engineer, Team Lead

Mar 2023 - Present

Boston, Massachusetts, United States

  • • Worked in the "core" editor's teams as senior software engineer and finally team lead in SignNow;
  • • Scaled SignNow revenue from $4M → $45M ARR through improved UX and new features;
  • • Led a frontend team of 9 engineers developing the core document editor (React, PDF.js);
  • • Implemented "shift left" approach to developing, implemented PW integration testing for the product, reducing manual QA load by 60%;
  • • Built an AI assistant to summarize uploaded documents using openAI APIs;
  • • Automated product localization into 10+ languages (AI + Crowdin);
  • • Migrated the legacy Angular 1.5 codebase to modern React/TypeScript;
  • • Implemented CI/CD pipelines via GitHub Actions.

airSlate

Full-time · 4 yrs 9 mos

Hybrid

Senior Frontend Engineer

Jul 2018 - Mar 2023

St Petersburg City, Russia

  • • Introduced Sentry and Grafana monitoring boards to identify and fix user issues early, significantly boosting customer satisfaction, product ratings, and retention;
  • • Built and deployed an A/B testing system that clarified business decision-making and boosted confidence in product hypotheses;
  • • Ensure accessibility compliance with ADA (Americans with Disabilities Act) and WCAG AAA standards, enhancing usability for disabled customers;
  • • Designed and implemented core document creation and editing capabilities, enabling advanced page management and PDF content modification;
  • • Implemented a formula and dependency engine for documents, enabling calculated fields and dynamic visibility through graph traversal;
  • • Automated product localization into 10+ languages (AI + Crowdin);
  • • Added functionality to group multiple documents together, enhancing document organization.

BIARUM

Full-time · 1 yr 5 mos

Hybrid

Senior Frontend Developer

Feb 2017 - Jun 2018

St Petersburg City, Russia

  • • Developed data visualization and geolocation-based analytics tools for US clients;
  • • Worked on projects related to traffic information platforms;
  • • Later transitioned to work on the PDFFiller project, which led to joining airSlate;
  • • Migrate web app PdfFiller from Adobe Flash to React.js.

Credinform Information Agency

Full-time · 1 yr 11 mos

On-site

Full Stack Developer

Apr 2015 - Feb 2017

St Petersburg City, Russia

  • • Contributed to the Globas information system;
  • • Migrated core application stack from Backbone.js/jQuery to React.

C.Nord Ltd.

Full-time · 1 yr

On-site

Full Stack Developer

May 2014 - Apr 2015

St Petersburg City, Russia

  • • Developed business processes in BPM Online CRM using C#;
  • • Maintained company’s e-commerce platform (PHP, Magento, JavaScript).

The HEINEKEN Company

Full-time · 3 yrs 1 mo

On-site

Full-stack Developer / IT Infrastructure support

May 2011 - May 2014

St Petersburg City, Russia

  • • Supported corporate IT infrastructure (Linux, Windows, networking);
  • • Developed internal portals using C# and SharePoint;
  • • Automated IT processes using FIM.

Education

IOSI

Engineer, Computer and Information Security

2004 - 2009

Grade: 4.5

Languages

Russian - fluence, English - advanced.