Cheat sheets for developers

The revision companion to Sefism's AI agents and MCP roadmap: ten chapters on the agent loop, tool calling, structured output, memory, multi-agent patterns, frameworks, building MCP servers, evals, guardrails and shipping. It comes in Python and TypeScript editions with working snippets in each. It suits developers who already call model APIs and want to revise a concept quickly, copy a working shape or catch the classic mistake before users do.

• AI
• Programming
• Web

A quick-revision book on building features with LLM APIs: tokens, prompts, streaming, structured output, tool calling, embeddings and RAG, caching, batching, cost, evals and security, in 8 chapters and 56 concepts. It comes in OpenAI, Anthropic and Gemini editions, each showing the same ideas with that provider's official Python SDK. It suits engineers who can already call an HTTP API in Python and now need their AI features to be reliable, affordable and safe.

• AI
• Backend
• Programming

A revision reference for personal branding as an engineer, in 6 chapters and 46 concepts: niche and positioning statement, a profile that works as a landing page, hooks and posts people read, a posting rhythm with a swipe file, networking through comments and weak ties, and the metrics worth tracking instead of vanity numbers. It follows the Sefism LinkedIn and personal branding roadmap stage for stage. Use it to check a draft post or profile section before you publish.

• Career
• Personal branding

A quick-revision companion to the Sefism frontend roadmap in ten chapters: how the web works, semantic HTML and accessibility, CSS layout, JavaScript the language and in the browser, Git and build tooling, your framework, TypeScript and testing, performance and security, and shipping a real product. It comes in React with Next.js, Vue with Nuxt and Angular editions, each concept with a short example and the common mistake. Skim a chapter before a project or a technical conversation, and follow the links when a concept needs depth.

• Web
• Frontend
• Programming

A quick-revision book on the Model Context Protocol for engineers building AI apps: hosts, clients and servers, JSON-RPC messages and lifecycle, transports, tools, resources and prompts, client features, OAuth for remote servers, building and testing servers with the official SDKs, security and tool design. It reflects the 2026-07-28 revision of the specification and notes what older revisions did differently. Use it while building or reviewing an MCP server, alongside the AI agents and MCP roadmap.

• AI
• Backend

A quick-revision companion to the DevOps and cloud roadmap in ten chapters: Linux and Bash, Git workflows, networking, Docker, the core AWS services, Terraform, CI/CD pipelines, Kubernetes and GitOps, observability and incident response, and security basics. It has 79 concepts, command and config snippets where they help, nine rules of thumb and a 142-term glossary. Use it to refresh a command or concept before you touch a server, a pipeline or a cluster.

• DevOps
• Cloud

A quick-revision companion to the AI engineering roadmap in eight chapters: how LLMs work, prompting and model APIs, RAG, evals, tool calling and structured output, MCP, agents and durable execution, and running AI systems in production. It comes in Python and TypeScript editions, with snippets using the official SDKs, Pydantic or Zod. Skim a chapter after each roadmap stage, before changing a prompt or model, or before a technical conversation about AI features.

• AI
• Programming
• Web

A community-maintained, plain-language accessibility checklist organised by area: content, global code, keyboard, images, headings, lists, controls, tables, forms, media, appearance, animation, colour contrast and mobile and touch. A practical pre-release check for designers and developers.

• Web
• Frontend

A quick-revision companion to the Data analytics roadmap: what analysts do, spreadsheets, SQL for analysis, statistics, cleaning and modelling, charts, dashboards and storytelling, and the first analyst role, plus a chapter for your tool. Power BI, Tableau and Python editions each have eight chapters with formulas, SQL, DAX, Tableau calculations or pandas snippets. Use it after each stage, while building a dashboard, and before an analyst technical round or take-home task.

• Databases
• Programming

A quick-revision companion to the Sefism backend roadmap: an essentials chapter for your stack, then terminal and Git, how HTTP works, relational databases and SQL, API design, authentication and API security, caching and queues, testing and CI/CD, and architecture and reliability. It comes in seven editions (Node.js, Python, Java, C#, Go, PHP and Rust), each concept with a short example and the mistake to avoid. Read a chapter before a project, an exam or a technical conversation.

• Web
• Backend
• Databases
• DevOps

The quick-revision companion to the Programming foundations roadmap: language basics, collections, errors and files, a chapter of essentials for Python, JavaScript, Java, C++ or C#, the command line and Git, how computers run code, data structures and Big-O, clean design, testing and shipping projects. Use it to check what you half remember before a project, an exam or a technical conversation.

• Programming
• Web
• Dev tools
• CS fundamentals

A quick-revision companion to the DSA roadmap in nine chapters: complexity, arrays and hashing, linked lists, stacks and queues, recursion, sorting and searching, trees and heaps, graphs, coding patterns, dynamic programming and timed practice habits. Costs are stated for every structure and algorithm, in Python, Java, C++ or JavaScript editions. Use it after each roadmap stage and before a contest or coding round.

• Programming
• DSA
• Web

The companion to the SQL and databases roadmap in PostgreSQL, MySQL and SQL Server editions: setup, single-table queries, joins, aggregation and window functions, schema design, changing data safely, indexes and query plans, SQL in applications, and a short MongoDB comparison. Each concept is a line or two with your dialect syntax and the classic mistake to avoid.

• Web
• Databases
• Backend

The OWASP Cheat Sheet Series is a free collection of short, expert-written guides on specific security tasks, such as authentication, session management, password storage, input validation, JSON Web Tokens, REST security, XSS and SQL injection prevention. It suits developers who need to implement something securely right now and want a concise list of what to do and which mistakes to avoid, rather than a textbook.

• Web
• Backend

A quick-revision companion to the Sefism full stack roadmap in seven chapters: web foundations, Git, npm and React, the server side, data modelling, APIs with authentication and caching, deployment with CI/CD, Linux and AWS, and shipping a complete product. It comes in Next.js, MERN, Django and React, and Spring Boot and React editions, so the server and database chapters match your stack. Skim a chapter before a project or a technical conversation, and use it as a checklist before you ship.

• Web
• Frontend
• Backend
• Databases

A revision reference for every step of a software job search, in 8 chapters and 55 concepts: target role and level, resume and keyword mirroring, proof of work, referrals and reply rate, what technical and behavioural rounds look for, the parts of an offer (total compensation, RSUs, options, vesting and cliff) and polite negotiation. It suits anyone in an active search and follows the Sefism Job search roadmap chapter by chapter. Use it to revise after each stage and to read an offer properly before you reply.

• Career
• Job search

A single page of Git recovery recipes by Katie Sylor-Miller, organised by the mistake you just made rather than by the command that fixes it. It is for anyone who uses Git daily and occasionally breaks something: committing to the wrong branch, needing to amend a commit, or losing work after a reset. A swear-free version and many translations exist.

• Dev tools

A free, community-written collection of short help pages for command line tools. Each page shows a handful of common, real examples instead of a full manual, so you can see how to extract an archive, find files or undo a git change in seconds. It covers common Linux, macOS, Windows and Android commands, and is available from a terminal client or in the browser.

• Dev tools

A free, open source framework by Jorge Fioranelli that describes what each engineering level expects across five axes: technology, system ownership, people, process and influence. Radar charts for developer, tech lead, technical program manager and engineering manager roles make the gap between your current level and the next one visible. Useful for preparing a promotion conversation or writing a case for someone else.

• Career
• Leadership

DevDocs combines the official documentation of hundreds of languages, frameworks and libraries into one fast, searchable interface that works offline. Operated by freeCodeCamp and open source, it offers instant search, keyboard navigation and downloadable doc sets. It replaces a browser full of documentation tabs with a single search box, which is especially helpful on unreliable connections.

• Web
• Frontend
• Programming

A revision reference for moving abroad for a tech job, in 8 chapters and 61 to 66 concepts per edition: the decision maths, how work routes are built, your destination's visa table, attestation and documents, local CV norms, finding sponsors and spotting scams, offer clauses and your first 90 days. It comes in Gulf, Germany and EU, UK and Ireland, and East Asia editions, written from official pages as of October 2026, and follows the Sefism Tech jobs abroad roadmap chapter by chapter.

• Career
• Job search

A reference in 10 chapters and 78 concepts for picking the right database for each job: a decision chart from data and access patterns to a database type, then relational, document, key-value and cache, search, vector, columnar and warehouse, graph, time series and object storage, with one at-a-glance card per type and tables of matching managed services on AWS, Azure and Google Cloud. It follows the Sefism Choosing the right database roadmap. Use it whenever you start a project or someone suggests adding a database.

• Web
• Databases
• Backend
• Cloud

A revision reference for securing and testing LLM apps and AI agents, in 9 chapters and two editions (app and agent security, red-teaming): security foundations, how LLM apps break, the OWASP LLM and agentic lists, MITRE ATLAS, prompt injection and guard layers, agent, tool and MCP security, the data and model supply chain, red-teaming tools and evals, monitoring and incidents, and career routes. It follows the Sefism AI security roadmap chapter by chapter, with no attack payloads.

• AI
• Security
• Testing

A standalone revision book on evaluating LLM apps and agents, in 10 chapters and 67 concepts: golden datasets, metrics by task type, LLM-as-judge and its biases, RAG and agent metrics, offline, online and CI evals, human review, the main tools as of October 2026 and a starter plan for your first week. It suits developers who change prompts and models and need to know whether things got better. Use it to pick a metric, check a judge and set a CI gate.

• AI
• Testing
• AI agents