{"name":"Denis Sineiko","title":"Senior Python Backend & Automation Engineer AI & LLM Integrations","website":"https://sineiko.com/","pdf_url":"https://sineiko.com/Denis_Sineiko_CV_Updated.pdf","contact":{"email":"denis.sineiko@gmail.com","phone":"+44 7957 099523","location":"Poole, Dorset, United Kingdom","linkedin":"https://www.linkedin.com/in/denissineiko/","work_authorization":"UK settled status; no sponsorship required"},"skills":{"Python & Backend":"Python 3, Flask / FastAPI, REST APIs, API integrations, requests, asyncio, async/await, HTTPX, concurrent processing, OOP, SOLID, type hints; Django","Automation & Integration":"Selenium, browser automation, external APIs, webhooks/callbacks, workflow orchestration, data validation, exception handling, file/PDF processing","Data":"MongoDB, PostgreSQL, BigQuery, SQL, Pandas, JSON, XML, CSV, Excel","Reliability & Testing":"pytest, unittest, API testing, Selenium E2E, Sentry, structured logging, health checks, production diagnostics, API-driven regression testing","Delivery":"Docker, GitLab CI/CD, Git, Pylint, AWS/ECS environments, deployment and release support","AI Integration":"OpenAI, Anthropic and Gemini APIs, n8n, AI agents and tool calling, document extraction, speech-to-text workflows, structured output validation, cross-model verification, deterministic fallbacks"},"sections":[{"title":"Professional Summary","text":"Senior Python backend and automation engineer with 9+ years across software automation, integrations and data engineering, including 6+ years owning a production platform in financial services. Built backend APIs and workflows across 30+ lender platforms, supporting thousands of weekly executions. Hands-on experience in Flask / FastAPI, API and browser integrations, concurrent processing, testing and production reliability, with technical ownership from architecture through release. Additional hands-on experience integrating LLMs and AI-assisted workflows."},{"title":"Professional Experience","text":"Senior Python Automation Engineer\nLoan.co.uk\nMarch 2020 - Present\nPoole, United Kingdom\nDesigned and built a production Python backend and automation platform from proof of concept, establishing reusable architecture across 30+ external lender platforms.\nSupport thousands of weekly workflow executions, submissions and data extraction operations, processing multiple cases concurrently to reduce adviser wait time and manual workload.\nDeveloped workflows for data retrieval, validation, submissions, document processing and portal uploads, replacing manual tasks taking approximately 15 minutes to 2 hours per case.\nDesigned, built and maintained production REST APIs using Flask and FastAPI for workflow automation, external integrations, callbacks, file operations, validation and error handling.\nBuilt production observability with Sentry, structured logging, health checks and workflow-level diagnostics to investigate API failures, timeouts and application/container incidents.\nDesigned an API-driven regression and validation framework covering approximately 50 to 60 end-to-end scenarios, using API checks, pytest, Selenium validation, screenshot evidence and failure diagnostics.\nOwn technical delivery across backend architecture, automation development, releases, dependency maintenance and production support, including performance and reliability improvements.\nIntegrated AI/LLM services for document and data extraction, applying structured output validation, inconsistency analysis, cross-model verification and deterministic fallback logic.\nEstablished coding standards and reusable integration patterns; provide code reviews, technical guidance and solution design support within a small product team.\nMaintain project-specific Docker images and GitLab CI/CD workflows with Pylint checks; collaborate with DevOps on AWS/ECS deployments and environment-level issues.\nETL Developer\nLUSH Digital\nJune 2018 - March 2020\nPoole, United Kingdom\nAutomated reconciliation between banking and retail datasets, achieving approximately 96% automatic matching and reducing manual work to exception handling.\nBuilt a reusable Python ETL and data collection framework from scratch across 16+ sources, including APIs, databases, files and business data feeds.\nCleaned and transformed business and global sales data for BigQuery, developing transformation logic, views and reporting datasets used across the organisation.\nCreated and supported 20+ Looker and Data Studio dashboards, translating operational data into metrics for teams and individual stakeholders.\nData Analyst\nFT Solutions Ltd\nSeptember 2016 - October 2017\nSouthampton, United Kingdom\nAutomated daily data cleaning, transformation, template mapping and Excel report generation, reducing routine processing time by approximately 50%.\nOptimised queries and processing logic across large datasets while maintaining data accuracy from raw input through final production output."},{"title":"Technical Skills","text":"Python & Backend\nPython 3, Flask / FastAPI, REST APIs, API integrations, requests, asyncio, async/await, HTTPX, concurrent processing, OOP, SOLID, type hints; Django\nAutomation & Integration\nSelenium, browser automation, external APIs, webhooks/callbacks, workflow orchestration, data validation, exception handling, file/PDF processing\nData\nMongoDB, PostgreSQL, BigQuery, SQL, Pandas, JSON, XML, CSV, Excel\nReliability & Testing\npytest, unittest, API testing, Selenium E2E, Sentry, structured logging, health checks, production diagnostics, API-driven regression testing\nDelivery\nDocker, GitLab CI/CD, Git, Pylint, AWS/ECS environments, deployment and release support\nAI Integration\nOpenAI, Anthropic and Gemini APIs, n8n, AI agents and tool calling, document extraction, speech-to-text workflows, structured output validation, cross-model verification, deterministic fallbacks"},{"title":"Independent Python & AI Projects","text":"Personal & Community Projects\n2024 - Present\nBuilt Python prototypes and project workflows using asyncio, async/await and HTTPX for concurrent API and integration workloads.\nDeveloped practical LLM-enabled workflows using OpenAI, Anthropic and Gemini APIs, including document extraction, speech-to-text processing and AI-assisted automation.\nBuilt n8n workflows and lightweight AI agents with tool calling for chatbot requests, information extraction and response suggestions, using structured outputs and validation around model responses."},{"title":"Selected Project","text":"Spotenda\nCommunity Booking Platform · In development\nDesigning and developing a community-focused booking platform using Python, Django and PostgreSQL to help small businesses promote their services and manage customer bookings without high platform costs. Building the application architecture and workflows for business onboarding, service management, availability and bookings, with AI-assisted features where useful."},{"title":"Community Support","text":"Informal Community Support\n2012 - Present\nOccasionally volunteer my time to help people in my community with technology and practical everyday tasks, particularly where professional help or replacement equipment may be difficult to afford."},{"title":"Education","text":"BSc (Hons) Computing, Software Engineering\nBournemouth University\n2012 - 2016"},{"title":"Languages","text":"English - Fluent | Russian - Native or Bilingual | Ukrainian - Native or Bilingual"}],"source_updated_at":"2026-10-20T21:43:12+00:00"}