Author: Markos Symeonides

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35 ChatGPT-5.5 Prompts for Startup Founders: Pitch Decks, Market Research, Competitive Analysis, and Fundraising Strategy
ByMarkos Symeonides July 3, 2026 Reading Time: 12 minutes

Masterclass: 35 ChatGPT-5.5 Prompts for Startup Founders — Pitch Deck, Market Research, Competitive Analysis, Fundraising, Go-to-Market ChatGPT-5.5 Masterclass for Startup Founders — 35 Prompts to Build, Validate, and Scale Published by chatgptaihub.com — a practical masterclass that gives founders immediate, copy-pasteable prompts for Pitch Decks, Market Research, Competitive Analysis, Fundraising,…

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The Complete Guide to GPT-5.5 Instant: Understanding OpenAI’s Most-Used Model and Its June 2026 Upgrade
ByMarkos Symeonides July 3, 2026 Reading Time: 21 minutes

The Complete Guide to GPT-5.5 Instant: Understanding OpenAI’s Most-Used Model and Its June 2026 Upgrade The Complete Guide to GPT-5.5 Instant: Understanding OpenAI’s Most-Used Model and Its June 2026 Upgrade Note on currency of information: This guide synthesizes community practices, model-class patterns, and publicly discussed design trends of “Instant”-style models….

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How to Use ChatGPT-5.5 for Financial Modeling: Revenue Forecasting, Scenario Analysis, and Investment Memo Generation
ByMarkos Symeonides July 3, 2026 Reading Time: 23 minutes

End-to-End Tutorial: Using ChatGPT-5.5 for Financial Modeling (Revenue Forecasting, Scenario Analysis, DCF, Sensitivity Tables, and Investment Memos) Using ChatGPT-5.5 for Financial Modeling: A Complete Guide Build robust revenue forecasts, run bull/bear/base scenarios, generate institutional-grade investment memos, get DCF assistance, and automate sensitivity tables—augmented by ChatGPT-5.5. Table of Contents Introduction and…

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OpenAI Codex Micro: The First AI Hardware Device for Developers — What We Know About the July 15 Launch
ByMarkos Symeonides July 3, 2026 Reading Time: 22 minutes

OpenAI Codex Micro: The First AI Hardware Device for Developers — What We Know About the July 15 Launch OpenAI Codex Micro: The First AI Hardware Device for Developers — What We Know About the July 15 Launch Type: News/Feature | Published: July 3, 2026 OpenAI’s first foray into developer-facing…

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Why OpenAI Is Merging Codex and ChatGPT: What the Unified AI Platform Means for Developers and Teams
ByMarkos Symeonides July 2, 2026 Reading Time: 21 minutes

Why OpenAI Is Merging Codex and ChatGPT: What the Unified AI Platform Means for Developers and Teams Table of Contents Executive Summary A Brief History of Codex and ChatGPT Codex origins: from language modeling to code ChatGPT origins: conversational UX meets coding Convergence pressures that made a merger inevitable Why…

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The Codex Refactoring Playbook: 20 Prompts for Legacy Code Modernization, Design Pattern Implementation, and Technical Debt Reduction
ByMarkos Symeonides July 2, 2026 Reading Time: 24 minutes

The Codex Refactoring Playbook: 20 Prompts for Legacy Code Modernization, Design Pattern Implementation, and Technical Debt Reduction This playbook provides twenty high-leverage prompts you can feed to OpenAI Codex (or a code-focused successor) to systematically refactor legacy codebases. The goal is to make modernization repeatable, measurable, and safe. Each prompt…

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30 ChatGPT-5.5 Prompts for Content Strategists: Editorial Calendars, SEO Briefs, Audience Research, and Content Repurposing
ByMarkos Symeonides July 2, 2026 Reading Time: 25 minutes

30 ChatGPT-5.5 Prompts for Content Strategists: Editorial Calendars, SEO Briefs, Audience Research, and Content Repurposing Table of Contents Why These Prompts Matter for Content Operations How to Use This Masterclass: Setup, Guardrails, and Output Schemas Editorial Calendar Planning Prompts (5) SEO Content Brief Prompts (5) Audience Persona Research Prompts (5)…

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The Complete Guide to OpenAI Codex Modes: Plan, Execute, and Review — Choosing the Right Mode for Every Task
ByMarkos Symeonides July 2, 2026 Reading Time: 22 minutes

The Complete Guide to OpenAI Codex Modes: Plan, Execute, and Review — Choosing the Right Mode for Every Task Table of Contents Introduction: Why Codex Modes Matter How Modes Work Across Desktop App, IDE Extensions, and CLI Plan Mode Deep Dive: From Objectives to a Concrete Task Graph Execute Mode…

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How to Use ChatGPT-5.5 for Automated Testing: Unit Tests, Integration Tests, and End-to-End Test Generation
ByMarkos Symeonides July 2, 2026 Reading Time: 25 minutes

How to Use ChatGPT-5.5 for Automated Testing: Unit Tests, Integration Tests, and End-to-End Test Generation Table of Contents Introduction Prerequisites and Test Strategy Alignment Prompt Patterns That Consistently Yield High-Quality Tests Unit Test Generation Across Python, JavaScript/TypeScript, and Java Edge Case Identification and Test Data Generation Integration Test Scaffolding with…

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Codex Record and Replay: How OpenAI’s Screen Recording Feature Turns Workflows Into Reusable AI Automation Skills
ByMarkos Symeonides July 2, 2026 Reading Time: 28 minutes

Codex Record and Replay: How OpenAI’s Screen Recording Feature Turns Workflows Into Reusable AI Automation Skills Table of Contents What Launched on July 1, 2026 Why It Matters for Workflow Automation How Codex Record & Replay Works The Capture Layer: Events, Context, and Privacy Representation: From Timeline to Skill Graph…

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