Guides for developers

A free, browsable index of system design concepts and worked questions, useful as a reference while you practise. A good way to judge whether the paid material is for you before paying for it.

The well known seventy five problem list, presented with the pattern each question belongs to instead of as a bare checklist. Free, and a reasonable place to test whether your preparation is actually working.

Per company breakdowns of the loop structure, the rounds you will face and what each one is scoring, for the major technology employers. Read the guide for your target company in the week before the loop, not the night before.

Recommendations, data pipelines, and a lot of writing about how engineering teams are organised and tooled. Read it for the developer experience posts as much as the architecture ones.

Messaging at scale, real time presence, search and the slow work of migrating a large PHP codebase without downtime. Practical, honest about constraints, and closer to the problems a normal company actually has.

Real time matching, geospatial indexing, payments and the long running story of moving off a monolith. The problems are concrete and easy to picture, which makes this a good blog to start with if architecture write ups usually lose you.

Posts on storage, caching, data centres and the infrastructure behind products used by billions of people. Uneven, and the good ones are very good, particularly anything about how a system was migrated while staying online.

The most consistently readable engineering blog in the industry. Deep posts on networking, DNS, TLS, caching and database scaling, plus unusually candid incident reports. If you only follow one engineering blog, this is a strong pick.

Long form write ups of decisions taken at a scale most of us will never work at, which is exactly why they are worth reading. Streaming architecture, caching, chaos engineering and personalisation, usually with the numbers and the mistakes included.

The gap between an agent that works in a notebook and one that runs for real is memory, deployment, monitoring, cost control and security. This repository is a set of hands on tutorials for exactly that layer, which almost nothing else covers properly.

Most teams reach for multiple agents too early and pay for it in cost, latency and debugging. This argues the other side clearly: when splitting work across agents genuinely helps, and when a single agent with better tools would have done the job. Short, and it will save you a rewrite.

A side by side comparison of the ways you can arrange multiple agents: sequential, concurrent, group chat, handoff and magentic. Each one gets its tradeoffs stated plainly, which is rarer than it should be. Use it as a decision aid rather than a tutorial.

Google's open source framework for building and deploying agents, with support for MCP and agent to agent communication built in. The docs are worth reading even outside Google Cloud because they treat deployment, evaluation and safety as part of the build rather than an afterthought.

A plain convention: put a markdown file at the root of your repository telling coding agents how to build, test and behave in that project. Tens of thousands of repositories now carry one. Adding it takes ten minutes and it is the cheapest way to stop an agent guessing at your build commands.

A small Python framework with only a few concepts to learn: agents, handoffs between them, guardrails on input and output, and tracing so you can see what happened. The docs are short enough to read end to end in an evening, which makes them a decent way to learn agent vocabulary even if you never use the SDK.

Agents fail at tools far more often than they fail at reasoning, and it is usually the tool's fault. This covers naming, parameter design, what to put in a description, and how to evaluate whether a model can actually use what you built. If you are writing an MCP server or a function schema, this is the piece to read first.

A real engineering write up of a shipped multi agent system: a lead agent that plans and subagents that search in parallel. Useful for the failure modes it admits to, like agents duplicating each other's work and token cost growing faster than the quality does. Read it before you decide you need more than one agent.

The single highest leverage thing you can learn once your agent basically works. Prompt tweaking gets you a little; deciding what is allowed into the context window and what gets left out gets you a lot. This explains how to think about that budget, and why long context models did not make the problem go away.

Google's internal guidance on code review, published free, covering both how to review and how to get your own change reviewed. The clearest available answer to what a code review is actually for.

Twelve principles for building services that deploy and scale cleanly, covering configuration, dependencies, statelessness, logging and parity between environments. An hour, and it explains most modern deployment conventions.

The ten most critical web application security risks, with the concrete failures behind each one and how to prevent them. The baseline every developer is assumed to know and many do not.

A short, widely cited essay on the three kinds of one to one and how to tell which one is happening. Fifteen minutes, and it permanently changes how you run and attend these meetings.

Stories and guidance from people who reached staff engineer, covering the archetypes of the role, how they got promoted and what the job actually involves. Free, and the clearest available answer to what the senior plus track is.

A free, detailed and unusually honest account of how to negotiate an engineering offer, written by someone who did it from a bootcamp background and documented the numbers. The single most useful free article on this list.